text:
Office of Scientific and Technical Information
Wind Turbine Generator System Power Performance Test Report for the ARE442 Wind Turbine
DOE Green Energy (OSTI)
This report summarizes the results of a power performance test that NREL conducted on the ARE 442 wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 12: Power Performance Measurements of Electricity Producing Wind Turbines, IEC 61400-12-1 Ed.1.0, 2005-12. However, because the ARE 442 is a small turbine as defined by IEC, NREL also followed Annex H that applies to small wind turbines. In these summary results, wind speed is normalized to sea-level air density.
van Dam, J.; Jager, D.
Wind Turbine Generator System Power Performance Test Report for the Entegrity EW50 Wind Turbine
Report on the results of the power performance test that the National Renewable Energy Laboratory (NREL) conducted on Entegrity Wind System Inc.'s EW50 small wind turbine.
Smith, J.; Huskey, A.; Jager, D.; Hur, J.
Power Performance Test Report for the SWIFT Wind Turbine
This report summarizes the results of a power performance test that NREL conducted on the SWIFT wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 12: Power Performance Measurements of Electricity Producing Wind Turbines, IEC 61400-12-1 Ed.1.0, 2005-12. However, because the SWIFT is a small turbine as defined by IEC, NREL also followed Annex H that applies to small wind turbines. In these summary results, wind speed is normalized to sea-level air density.
Mendoza, I.; Hur, J.
Effects of Changing Atmospheric Conditions on Wind Turbine Performance (Poster)
SciTech Connect
Multi-megawatt, utility-scale wind turbines operate in turbulent and dynamic winds that impact turbine performance in ways that are gradually becoming better understood. This poster presents a study made using a turbulent flow field simulator (TurbSim) and a Turbine aeroelastic simulator (FAST) of the response of a generic 1.5 MW wind turbine to changing inflow. The turbine power output is found to be most sensitive to wind speed and turbulence intensity, but the relationship depends on the wind speed with respect to the turbine's rated wind speed. Shear is found to be poorly correlated to power. A machine learning method called 'regression trees' is used to create a simple model of turbine performance that could be used as part of the wind resource assessment process. This study has used simple flow fields and should be extended to more complex flows, and validated with field observations.
Clifton, A.
Wind Turbines
Energy.gov (U.S. Department of Energy (DOE))
Although all wind turbines operate on similar principles, several varieties are in use today. These include horizontal axis turbines and vertical axis turbines.
Design of wind turbines with Ultra-High Performance Concrete
E-Print Network (OSTI)
Ultra-High Performance Concrete (UHPC) has proven an asset for bridge design as it significantly reduces costs. However, UHPC has not been applied yet to wind turbine technology. Design codes do not propose any recommendations ...
Jammes, Fran�ois-Xavier
Performance of a Wind-Profiling Lidar in the Region of Wind Turbine Rotor Disks
Science Conference Proceedings (OSTI)
As the wind energy sector continues to grow, so does the need for reliable vertical wind profiles in the assessment of wind resources and turbine performance. In situ instrumentation mounted on meteorological towers can rarely probe the atmosphere ...
Matthew L. Aitken; Michael E. Rhodes; Julie K. Lundquist
The EPRI/DOE Utility Wind Turbine Performance Verification Program
In 1992, the Electric Power Research Institute (EPRI) and the US Department of Energy (DOE) initiated the Utility Wind Turbine Performance Verification Program (TVP). This paper provides an overview of the TVP, its purpose and goals, and the participating utility projects. Improved technology has significantly reduced the cost of energy from wind turbines since the early 1980s. In 1992, turbines were producing electricity for about $0.07--$0.09/kilowatt-hour (kWh) (at 7 m/s [16 mph sites]), compared with more than $0.30/kWh in 1980. Further technology improvements were expected to lower the cost of energy from wind turbines to $0.05/kWh. More than 17,000 wind turbines, totaling more than 1,500 MW capacity, were installed in the US, primarily in California and Hawaii. The better wind plants had availabilities above 95%, capacity factors exceeding 30%, and operation and maintenance costs of $0.01/kWh. However, despite improving technology, EPRI and DOE recognized that utility use of wind turbines was still largely limited to turbines installed in California and Hawaii during the 1980s. Wind resource assessments showed that other regions of the US, particularly the Midwest, had abundant wind resources. EPRI and DOE sought to provide a bridge from utility-grade turbine development programs under way to commercial purchases of the wind turbines. The TVP was developed to allow utilities to build and operate enough candidate turbines to gain statistically significant operating and maintenance data.
Calvert, S.; Goldman, P. [Department of Energy, Washington, DC (United States); DeMeo, E.; McGowin, C. [Electric Power Research Inst., Palo Alto, CA (United States); Smith, B.; Tromly, K. [National Renewable Energy Lab., Golden, CO (United States)
Applications: Operational wind turbines
Capability Applications: Operational wind turbines Benefits: Optimize wind turbine performance Summary: Researchers at the Los Alamos National Laboratory (LANL) Intelligent Wind Turbine Program are developing a multi-physics modeling approach for the analysis of wind turbines in the presence of realistic
Wind Turbine Generator System Power Performance Test Report for the Gaia-Wind 11-kW Wind Turbine
This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. It is a power performance test that the National Renewable Energy Laboratory (NREL) conducted on the Gaia-Wind 11-kW small wind turbine.
Huskey, A.; Bowen, A.; Jager, D.
Summary of currently used wind turbine performance prediction computer codes
Informaion on currently used wind turbine aerodynamic/economic performance prediction codes is compiled and presented. Areas of interest to wind energy researchers that are not included in the reported codes are identified. Areas which are weak in experimental support are also identified.
Perkins, F.
Optimizing small wind turbine performance in battery charging applications
Many small wind turbine generators (10 kW or less) consist of a variable speed rotor driving a permanent magnet synchronous generator (alternator). One application of such wind turbines is battery charging, in which the generator is connected through a rectifier to a battery bank. The wind turbine electrical interface is essentially the same whether the turbine is part of a remote power supply for telecommunications, a standalone residential power system, or a hybrid village power system, in short, any system in which the wind generator output is rectified and fed into a DC bus. Field experience with such applications has shown that both the peak power output and the total energy capture of the wind turbine often fall short of expectations based on rotor size and generator rating. In this paper, the authors present a simple analytical model of the typical wind generator battery charging system that allows one to calculate actual power curves if the generator and rotor properties are known. The model clearly illustrates how the load characteristics affect the generator output. In the second part of this paper, the authors present four approaches to maximizing energy capture from wind turbines in battery charging applications. The first of these is to determine the optimal battery bank voltage for a given WTG. The second consists of adding capacitors in series with the generator. The third approach is to place an optimizing DC/DC voltage converter between the rectifier and the battery bank. The fourth is a combination of the series capacitors and the optimizing voltage controller. They also discuss both the limitations and the potential performance gain associated with each of the four configurations.
Drouilhet, S; Muljadi, E; Holz, R [National Renewable Energy Lab., Golden, CO (United States). Wind Technology Div.; Gevorgian, V [State Engineering Univ. of Armenia, Yerevan (Armenia)
Performance Testing of a Small Vertical-Axis Wind Turbine , S. Tullis2
Performance Testing of a Small Vertical-Axis Wind Turbine R. Bravo1 , S. Tullis2 , S. Ziada3 of electric production [1]. Although most performance testing for small-scale wind turbines is conducted vertical-axis wind turbines (VAWT) in urban settings, full-scale wind tunnel testing of a prototype 3.5 k
Tullis, Stephen
PERFORMANCE ENHANCEMENT OF WIND TURBINE POWER REGULATION BY SWITCHED LINEAR CONTROL D.J.Leith W Power regulation of horizontal-axis grid-connected up-wind constant-speed pitch-regulated wind turbines, switched linear control is more suited for application to wind turbines than the nonlinear control strategy
Duffy, Ken
Plasma Aerodynamic Control Effectors for Improved Wind Turbine Performance
Orbital Research Inc is developing an innovative Plasma Aerodynamic Control Effectors (PACE) technology for improved performance of wind turbines. The PACE system is aimed towards the design of "smart" rotor blades to enhance energy capture and reduce aerodynamic loading and noise using flow-control. The PACE system will provide ability to change aerodynamic loads and pitch distribution across the wind turbine blade without any moving surfaces. Additional benefits of the PACE system include reduced blade structure weight and complexity that should translate into a substantially reduced initial cost. During the Phase I program, the ORI-UND Team demonstrated (proof-of-concept) performance improvements on select rotor blade designs using PACE concepts. Control of both 2-D and 3-D flows were demonstrated. An analytical study was conducted to estimate control requirements for the PACE system to maintain control during wind gusts. Finally, independent laboratory experiments were conducted to identify promising dielectric materials for the plasma actuator, and to examine environmental effects (water and dust) on the plasma actuator operation. The proposed PACE system will be capable of capturing additional energy, and reducing aerodynamic loading and noise on wind turbines. Supplementary benefits from the PACE system include reduced blade structure weight and complexity that translates into reduced initial capital costs.
Mehul P. Patel; Srikanth Vasudevan; Robert C. Nelson; Thomas C. Corke
of a building was explored [2]. Referred to such applications, a VAWT can be so small in physical size that its by the present authors to study the aerodynamic performance of small VAWTs using the experimental and numerical1 WIND-TUNNEL STUDY ON AERODYNAMIC PERFORMANCE OF SMALL VERTICAL-AXIS WIND TURBINES J. J. Miau*1
Leu, Tzong-Shyng "Jeremy"
NREL: Wind Research - Large Wind Turbine Research
NLE Websites -- All DOE Office Websites (Extended Search)
Wind Research Search More Search Options Site Map Printable Version Large Wind Turbine Research NREL's utility scale wind system research addresses performance and...
Reference wind speed distributions and height profiles for wind turbine design and performance evaluation applications. [USA
The purpose of this report is to provide a set of reference or standard values of wind profiles, wind speed distributions and their effects on wind turbine performance for engineering design applications. Based on measured Weibull distribution parameters, representative average, low, and high variance data are given for height profiles of mean, 25 percentile, and 75 percentile wind speeds; and for wind speed probability density (velocity frequency) functions and cumulative probability (velocity duration) functions at selected heights. Results of a sensitivity analysis of the dependence of wind turbine performance parameters on cut-in speed, and rated speed for various mean wind and wind variance regimes are also presented. Wind turbine performance is expressed in terms of capacity factor (ratio of mean power output to rated power) and recovery factor (ratio of mean energy output to energy theoretically available in the wind). The representative high, mean, and low variance cases were determined from calculated Weibull distributions at 140 sites across the Continental U.S., and all of the representative functions are evaluated at mean wind speeds of 4, 5, 6, 7, and 8 m/s at standard 10 m level.
Justus, C.G.; Hargraves, W.R.; Mikhail, A.
Energy Basics: Wind Turbines
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Energy Basics Renewable Energy Printable Version Share this resource Biomass Geothermal Hydrogen Hydropower Ocean Solar Wind Wind Turbines Wind Resources Wind Turbines...
Wind turbine
DOE Patents (OSTI)
A wind turbine of the type having an airfoil blade (15) mounted on a flexible beam (20) and a pitch governor (55) which selectively, torsionally twists the flexible beam in response to wind turbine speed thereby setting blade pitch, is provided with a limiter (85) which restricts unwanted pitch change at operating speeds due to torsional creep of the flexible beam. The limiter allows twisting of the beam by the governor under excessive wind velocity conditions to orient the blades in stall pitch positions, thereby preventing overspeed operation of the turbine. In the preferred embodiment, the pitch governor comprises a pendulum (65,70) which responds to changing rotor speed by pivotal movement, the limiter comprising a resilient member (90) which engages an end of the pendulum to restrict further movement thereof, and in turn restrict beam creep and unwanted blade pitch misadjustment.
Cheney, Jr., Marvin C. (Glastonbury, CT)
Feasibility Study of Economics and Performance of Wind Turbine...
Wind Turbine Generators at the Newport Indiana Chemical Depot Site Joseph Owen Roberts and Gail Mosey Produced under direction of U.S. Environmental Protection Agency (EPA) by the...
Cooperative field test program for wind energy systems: Effects of precipitation on wind turbine performance
The purpose of this research is to examine the effect of precipitation on wind turbine performance. This study will be conducted at the Whisky Run windfarm on the southern Oregon coast. Precipitation has been shown to cause significant degradation in the performance of the MOD-O wind turbine by Corrigan and DeMiglio (1985), who found performance reductions of up to 20% for light rainfall, 30% for moderate rainfall and 36% for snow and drizzle. There are several penalties due to rainfall, but it appears that most of the performance degradation is due to rain induced roughness. The Whisky Run windfarm receives around 60 inches of rain per year most of which occurs from October through April. During the summer months drizzle is an occasional weather phenomena. Pacific Wind Energy (PWE) and Pacific Power and Light (PP L) propose to examine the effect of precipitation on wind turbine performance. The Whisky Run windfarm is unique among windfarms because the power sales contract is set up such that the wind farm is considered a research project and the participants have agreed to engage in research that will benefit the industry. PP L will be providing all of the instrumentation except for the recording rate of rain gage. PWE will be performing the analysis of the data and project management.
Not Available
Aerodynamic and Performance Measurements on a SWT-2.3-101 Wind Turbine
This paper provides an overview of a detailed wind turbine field experiment being conducted at NREL under U.S. Department of Energy sponsorship. The purpose of the experiment is to obtain knowledge about the aerodynamics, performance, noise emission and structural characteristics of the Siemens SWT-2.3-101 wind turbine.
Medina, P.; Singh, M.; Johansen, J.; Jove, A.R.; Machefaux, E.; Fingersh, L. J.; Schreck, S.
Wind Turbinie Generator System Power Performance Test Report for the Mariah Windspire 1-kW Wind Turbine
This report summarizes the results of a power performance test that NREL conducted on the Mariah Windspire 1-kW wind turbine. During this test, two configurations were tested on the same turbine. In the first configuration, the turbine inverter was optimized for power production. In the second configuration, the turbine inverter was set for normal power production. In both configurations, the inverter experienced failures and the tests were not finished.
The Influence of Unsteady Wind on the Performance and Aerodynamics of Vertical Axis Wind Turbines.
??Interest in small�scale wind turbines as energy sources in the built environment has increased due to the desire of consumers in urban areas to reduce� (more)
Danao, Louis Angelo
Investigation of transient models and performances for a doubly fed wind turbine under a grid fault
In order to investigate the impacts of the integration of wind farms into utilities network, it is necessary to analyze the transient performances of wind turbine generation systems (WTGS) with the appropriate transient models. According to the grid ... Keywords: crowbar, doubly fed induction generator, drive train, transient performance, wind power
Mingyu Wang; Bin Zhao; Hui Li; Chao Yang; Renjie Ye; Z. Chen
Investigation of vortex generators for augmentation of wind turbine power performance
This study focuses on the use of vortex generators (VGs) for performance augmentation of the stall-regulated AWT-26 wind turbine. The goal was to design a VG array which would increase annual energy production (AEP) by increasing power output at moderate wind speeds, without adversely affecting the loads or stall-regulation performance of the turbine. Wind tunnel experiments were conducted at the University of Washington to evaluate the effect of VGs on the AWT-26 blade, which is lofted from National Renewable Energy Laboratory (NREL) S-series airfoils. Based on wind-tunnel results and analysis, a VG array was designed and then tested on the AWT-26 prototype, designated P1. Performance and loads data were measured for P1, both with and without VGs installed. the turbine performance with VGs met most of the design requirements; power output was increased at moderate wind speeds with a negligible effect on peak power. However, VG drag penalties caused a loss in power output for low wind speeds, such that performance with VGs resulted in a net decrease in AEP for sites having annual average wind speeds up to 8.5 m/s. While the present work did not lead to improved AEP for the AWT-2 turbine, it does provide insight into performance augmentation of wind turbines with VGs. The safe design of a VG array for a stall-regulated turbine has been demonstrated, and several issues involving optimal performance with VGs have been identified and addressed. 15 refs., 34 figs., 10 tabs.
Griffin, D.A. [Lynette (R.) and Associates, Seattle, WA (United States)
Wind Turbine Maintenance Guide
This guideline provides component-level information regarding the maintenance of major components associated with a wind turbine. It combines recommendations offered by major equipment manufacturers with lessons learned from owner/operators of wind turbine facilities.
Photo of a crane lifting the blades onto a wind turbine that reads 'U.S. Department of Energy, NREL.' You can learn more about horizontal axis turbines from the EERE Wind Program's...
A Dynamic Wind Turbine Simulator of the Wind Turbine Generator System
To study dynamic performances of wind turbine generator system (WTGS), and to determine the control structures in laboratory. The dynamic torque generated by wind turbine (WT) must be simulated. In there paper, a dynamic wind turbine emulator (WTE) is ... Keywords: dynamic wind turbine emulation, wind shear, tower shadow, torque compensation
Lei Lu; Zhen Xie; Xing Zhang; Shuying Yang; Renxian Cao
Wind Turbines Under Atmospheric Icing Conditions - Ice Accretion Modeling, Aerodynamics, and Control Strategies for Mitigating Performance Degradation.
??This thesis presents a combined engineering methodology of ice accretion, airfoil data, and rotor performance analysis of wind turbines subject to moderate atmospheric icing conditions.� (more)
Brillembourg, Dwight
Power Performance Test Report for the Viryd CS8 Wind Turbine
This report contains the results of the power performance test that was performed on a Viryd CS8 wind turbine as part of the DOE Independent Testing project. The test is an accredited test to the IEC 61400-12-1 power performance standard.
Roadman, J.; Murphy, M.; van Dam, J.
Comparison of Projections to Actual Performance in the DOE-EPRI Wind Turbine Verification Program
As part of the US Department of Energy/Electric Power Research Institute (DOE-EPRI) Wind Turbine Verification Program (TVP), Global Energy Concepts (GEC) worked with participating utilities to develop a set of performance projections for their projects based on historical site atmospheric conditions, turbine performance data, operation and maintenance (O and M) strategies, and assumptions about various energy losses. After a preliminary operation period at each project, GEC compared the actual performance to projections and evaluated the accuracy of the data and assumptions that formed the performance projections. This paper presents a comparison of 1999 power output, turbine availability, and other performance characteristics to the projections for TVP projects in Texas, Vermont, Iowa, Nebraska, Wisconsin, and Alaska. Factors that were overestimated or underestimated are quantified. Actual wind speeds are compared to projections based on long-term historical measurements. Turbine power curve measurements are compared with data provided by the manufacturers, and loss assumptions are evaluated for accuracy. Overall, the projects performed well, particularly new commercial turbines in the first few years of operation. However, some sites experienced below average wind resources and greater than expected losses. The TVP project owners successfully developed and constructed wind power plants that are now in full commercial operation, serving a total of approximately 12,000 households.
Rhoads, H.; VandenBosche, J.; McCoy, T.; Compton, A. (Global Energy Concepts, LLC); Smith, B. (National Renewable Energy Laboratory)
Wind Turbines | Department of Energy
Energy.gov (U.S. Department of Energy (DOE)) Indexed Site
Turbines Wind Turbines July 30, 2013 - 2:58pm Addthis Energy 101: Wind Turbines Basics This video explains the basics of how wind turbines operate to produce clean power from an...
The wind turbine
In this paper we present the modeling of a wing turbine, using the Euler Lagrange method and circuits theory. We get the mathematical equation (modeling) that describes the wind turbine and we simulate it using the mathlab program. Keywords: modeling, simulation, wind turbine
Jos� De Jes�s Rubio Avila; Andr�s Ferreira Ram�rez; Genaro Deloera Flores; Mart�n Salazar Pereyra; Fernando Baruch Santillanes Posada
NREL: Wind Research - Small Wind Turbine Development
Small Wind Turbine Development Small Wind Turbine Development A photo of Southwest Windpower's Skystream wind turbine in front of a home. PIX14936 Southwest Windpower's Skystream wind turbine. A photo of the Endurance wind turbine. PIX15006 The Endurance wind turbine. A photo of the Atlantic Orient Corporation 15/50 wind turbine at the National Wind Technology Center. PIX07301 The Atlantic Orient Corporation 15/50 wind turbine at the National Wind Technology Center. NREL supports continued market expansion of small wind turbines by funding manufacturers through competitive solicitations (i.e., subcontracts and/or grants) to refine prototype systems leading to commercialization. Learn more about the turbine development projects below. Skystream NREL installed and tested an early prototype of this turbine at the
Real time wind turbine simulator.
??A novel dynamic real-time wind turbine simulator (WTS) is developed in this thesis, which is capable of reproducing dynamic behavior of real wind turbine. The� (more)
Gong, Bing
SERI advanced wind turbine blades
The primary goal of the Solar Energy Research Institute`s (SERI) advanced wind turbine blades is to convert the kinetic energy in the wind into mechanical energy in an inexpensive and efficient manner. To accomplish this goal, advanced wind turbine blades have been developed by SERI that utilize unique airfoil technology. Performance characteristics of the advanced blades were verified through atmospheric testing on fixed-pitch, stall-regulated horizontal-axis wind turbines (HAWTs). Of the various wind turbine configurations, the stall-regulated HAWT dominates the market because of its simplicity and low cost. Results of the atmospheric tests show that the SERI advanced blades produce 10% to 30% more energy than conventional blades. 6 refs.
Tangler, J.; Smith, B.; Jager, D.
The primary goal of the Solar Energy Research Institute's (SERI) advanced wind turbine blades is to convert the kinetic energy in the wind into mechanical energy in an inexpensive and efficient manner. To accomplish this goal, advanced wind turbine blades have been developed by SERI that utilize unique airfoil technology. Performance characteristics of the advanced blades were verified through atmospheric testing on fixed-pitch, stall-regulated horizontal-axis wind turbines (HAWTs). Of the various wind turbine configurations, the stall-regulated HAWT dominates the market because of its simplicity and low cost. Results of the atmospheric tests show that the SERI advanced blades produce 10% to 30% more energy than conventional blades. 6 refs.
Wind Turbines and Health
Wind power has been gaining prominence as a viable sustainable alternative to other forms of energy production. Studies have found that there is increasing population demand for �green� energy 1,2. In Australia, this has been encouraged by the introduction of the Renewable Energy (Electricity) Act in 2000 and the Renewable Energy Target Scheme in 2009. As with any new technology, wind turbines are not without controversy. Those who oppose the development of wind farms contend that wind turbines can adversely impact the health of individuals living in close proximity. Do wind turbines impact on health? Concerns regarding the adverse health impacts of wind turbines focus on infrasound noise, electromagnetic interference, shadow flicker and blade glint produced
unknown authors
Wind power has been gaining prominence as a viable sustainable alternative to other forms of energy production. Studies have found that there is increasing population demand for �green� energy1,2. In Australia, this has been encouraged by the introduction of the Renewable Energy (Electricity) Act in 2000 and the Renewable Energy Target Scheme in 2009. As with any new technology, wind turbines are not without controversy. Those who oppose the development of wind farms contend that wind turbines can adversely impact the health of individuals living in close proximity. Do wind turbines impact on health? Concerns regarding the adverse health impacts of wind turbines focus on infrasound noise, electromagnetic interference, shadow flicker and blade glint produced
Wind turbine | Open Energy Information
Open Energy Info (EERE)
turbine turbine Jump to: navigation, search Dictionary.png Wind turbine: A machine that converts wind energy to mechanical energy; typically connected to a generator to produce electricity. Other definitions:Wikipedia Reegle Contents 1 Types of Wind Turbines 1.1 Vertical Axis Wind Turbines 1.2 Horizontal Axis Wind Turbines 2 Wind Turbine Sizes 3 Components of a Wind Turbine 4 References Types of Wind Turbines There are two basic wind turbine designs: those with a vertical axis (sometimes referred to as VAWTs) and those with a horizontal axis (sometimes referred to as HAWTs). There are several manufacturers of vertical axis turbines, but they have not penetrated the "utility scale" (100 kW capacity and larger) market to the same degree as horizontal axis turbines.[1]
A low order model for vertical axis wind turbines
A new computational model for initial sizing and performance prediction of vertical axis wind turbines
Drela, Mark
NREL: Wind Research - Small Wind Turbine Research
Small Wind Turbine Research Small Wind Turbine Research The National Renewable Energy Laboratory and U.S. Department of Energy (NREL/DOE) Small Wind Project's objectives are to reduce barriers to wind energy expansion, stabilize the market, and expand the number of small wind turbine systems installed in the United States. "Small wind turbine" refers to a turbine smaller than or equal to 100 kilowatts (kW). "Distributed wind" includes small and midsize turbines (100 kW through 1 megawatt [MW]). Since 1996, NREL's small wind turbine research has provided turbine testing, turbine development, and prototype refinement leading to more commercially available small wind turbines. Work is conducted under the following areas. You can also learn more about state and federal policies
NREL: Wind Research - Midsize Wind Turbine Research
Midsize Wind Turbine Research Midsize Wind Turbine Research To facilitate the development and commercialization of midsize wind turbines (turbines with a capacity rating of more than 100 kW up to 1 MW), the U.S. Department of Energy (DOE) and NREL launched the Midsize Wind Turbine Development Project. In its latest study, NREL determined that there is a substantial market for midsize wind turbines. One of the most significant barriers to the midsize turbine market is the lack of turbines available for deployment; there are few midsize turbines on the market today. The objectives of the Midsize Wind Turbine Development Project are to reduce the barriers to wind energy expansion by filling an existing domestic technology gap; facilitate partnerships; accelerate maturation of existing U.S. wind energy businesses; and incorporate process improvement
Vertical axis wind turbines
A vertical axis wind turbine is described. The wind turbine can include a top ring, a middle ring and a lower ring, wherein a plurality of vertical airfoils are disposed between the rings. For example, three vertical airfoils can be attached between the upper ring and the middle ring. In addition, three more vertical airfoils can be attached between the lower ring and the middle ring. When wind contacts the vertically arranged airfoils the rings begin to spin. By connecting the rings to a center pole which spins an alternator, electricity can be generated from wind.
Krivcov, Vladimir (Miass, RU); Krivospitski, Vladimir (Miass, RU); Maksimov, Vasili (Miass, RU); Halstead, Richard (Rohnert Park, CA); Grahov, Jurij (Miass, RU)
Wind Turbine Acoustic Noise A white paper
Wind Turbine Acoustic Noise A white paper Prepared by the Renewable Energy Research Laboratory...................................................................... 8 Sound from Wind Turbines .............................................................................................. 10 Sources of Wind Turbine Sound
Massachusetts at Amherst, University of
Measured and predicted rotor performance for the SERI advanced wind turbine blades
Measured and predicted rotor performance for the SERI advanced wind turbine blades were compared to assess the accuracy of predictions and to identify the sources of error affecting both predictions and measurements. An awareness of these sources of error contributes to improved prediction and measurement methods that will ultimately benefit future rotor design efforts. Propeller/vane anemometers were found to underestimate the wind speed in turbulent environments such as the San Gorgonio Pass wind farm area. Using sonic or cup anemometers, good agreement was achieved between predicted and measured power output for wind speeds up to 8 m/sec. At higher wind speeds an optimistic predicted power output and the occurrence of peak power at wind speeds lower than measurements resulted from the omission of turbulence and yaw error. In addition, accurate two-dimensional (2-D) airfoil data prior to stall and a post stall airfoil data synthesization method that reflects three-dimensional (3-D) effects were found to be essential for accurate performance prediction. 11 refs.
Tangler, J.; Smith, B.; Kelley, N.; Jager, D.
NREL: Wind Research - Small Wind Turbine Tests and Testing Approach
Association of Laboratory Accreditation (A2LA). The suite of tests conducted on small wind turbines includes acoustic noise emissions, duration, power performance, power...
Chapter 14: Wind Turbine Control Systems
Wind turbines are complex, nonlinear, dynamic systems forced by gravity, stochastic wind disturbances, and gravitational, centrifugal, and gyroscopic loads. The aerodynamic behavior of wind turbines is nonlinear, unsteady, and complex. Turbine rotors are subjected to a complicated three-dimensional turbulent wind inflow field that drives fatigue loading. Wind turbine modeling is also complex and challenging. Accurate models must contain many degrees of freedom (DOF) to capture the most important dynamic effects. The rotation of the rotor adds complexity to the dynamics modeling. Designs of control algorithms for wind turbines must account for these complexities. Algorithms must capture the most important turbine dynamics without being too complex and unwieldy. Off-the-shelf commercial soft ware is seldom adequate for wind turbine dynamics modeling. Instead, specialized dynamic simulation codes are usually required to model all the important nonlinear effects. As illustrated in Figure 14-1, a wind turbine control system consists of sensors, actuators and a system that ties these elements together. A hardware or software system processes input signals from the sensors and generates output signals for actuators. The main goal of the controller is to modify the operating states of the turbine to maintain safe turbine operation, maximize power, mitigate damaging fatigue loads, and detect fault conditions. A supervisory control system starts and stops the machine, yaws the turbine when there is a significant yaw misalignment, detects fault conditions, and performs emergency shut-downs. Other parts of the controller are intended to maximize power and reduce loads during normal turbine operation.
Wright, A. D.
Balancing Performance, Noise, Cost, and Aesthetics in the Southwest Windpower "Storm" Wind Turbine: Preprint
This paper describes the design, fabrication, and testing of an 1800-watt innovative small wind turbine and discusses the importance of idiosyncratic aerodynamic and aeroacoustic airfoil characteristics for clean airfoils at low Reynolds numbers.
Migliore, P.; Green, J.; Calley, D.; Lonjaret, J.
Airborne Wind Turbine
Broad Funding Opportunity Announcement Project: Makani Power is developing an Airborne Wind Turbine (AWT) that eliminates 90% of the mass of a conventional wind turbine and accesses a stronger, more consistent wind at altitudes of near 1,000 feet. At these altitudes, 85% of the country can offer viable wind resources compared to only 15% accessible with current technology. Additionally, the Makani Power wing can be economically deployed in deep offshore waters, opening up a resource which is 4 times greater than the entire U.S. electrical generation capacity. Makani Power has demonstrated the core technology, including autonomous launch, land, and power generation with an 8 meter wingspan, 20 kW prototype. At commercial scale, Makani Power aims to develop a 600 kW, 28 meter wingspan product capable of delivering energy at an unsubsidized cost competitive with coal, the current benchmark for low-cost power.
Tornado type wind turbines
A tornado type wind turbine has a vertically disposed wind collecting tower with spaced apart inner and outer walls and a central bore. The upper end of the tower is open while the lower end of the structure is in communication with a wind intake chamber. An opening in the wind chamber is positioned over a turbine which is in driving communication with an electrical generator. An opening between the inner and outer walls at the lower end of the tower permits radially flowing air to enter the space between the inner and outer walls while a vertically disposed opening in the wind collecting tower permits tangentially flowing air to enter the central bore. A porous portion of the inner wall permits the radially flowing air to interact with the tangentially flowing air so as to create an intensified vortex flow which exits out of the top opening of the tower so as to create a low pressure core and thus draw air through the opening of the wind intake chamber so as to drive the turbine.
Hsu, Cheng-Ting (Ames, IA)
Wind turbine spoiler
An aerodynamic spoiler system for a vertical axis wind turbine includes spoilers on the blades initially stored near the rotor axis to minimize drag. A solenoid latch adjacent the central support tower releases the spoilers and centrifugal force causes the spoilers to move up the turbine blades away from the rotor axis, thereby producing a braking effect and actual slowing of the associated wind turbine, if desired. The spoiler system can also be used as an infinitely variable power control by regulated movement of the spoilers on the blades over the range between the undeployed and fully deployed positions. This is done by the use of a suitable powered reel and cable located at the rotor tower to move the spoilers.
Sullivan, William N. (Albuquerque, NM)
Westwind Wind Turbines | Open Energy Information
Westwind Wind Turbines Jump to: navigation, search Name Westwind Wind Turbines Place Northern Ireland, United Kingdom Zip BT29 4TF Sector Wind energy Product Northern Ireland based...
Howden Wind Turbines Ltd | Open Energy Information
Howden Wind Turbines Ltd Jump to: navigation, search Name Howden Wind Turbines Ltd Place United Kingdom Sector Wind energy Product Howden was a manufacturer of wind turbines in the...
Dynamic Simulation of DFIG Wind Turbines on FPGA Boards
Dynamic Simulation of DFIG Wind Turbines on FPGA Boards Hao Chen, Student Member, IEEE, Song Sun is a friction coefficient. The wind turbine model is based on the relation between the upstream wind speed V w + 1 where p is the air density; Rw is the wind turbine radius; cp (A, (3) is the performance
Zambreno, Joseph A.
Airfoils for wind turbine
Airfoils for the blade of a wind turbine wherein each airfoil is characterized by a thickness in a range from 16%-24% and a maximum lift coefficient designed to be largely insensitive to roughness effects. The airfoils include a family of airfoils for a blade 15 to 25 meters in length, a family of airfoils for a blade 1 to 5 meters in length, and a family of airfoils for a blade 5 to 10 meters in length.
Tangler, James L. (Boulder, CO); Somers, Dan M. (State College, PA)
Airfoils are disclosed for the blade of a wind turbine wherein each airfoil is characterized by a thickness in a range from 16%-24% and a maximum lift coefficient designed to be largely insensitive to roughness effects. The airfoils include a family of airfoils for a blade 15 to 25 meters in length, a family of airfoils for a blade 1 to 5 meters in length, and a family of airfoils for a blade 5 to 10 meters in length. 10 figs.
Tangler, J.L.; Somers, D.M.
State of the Art in Floating Wind Turbine Design Tools
This paper presents an overview of the simulation codes available to the offshore wind industry that are capable of performing integrated dynamic calculations for floating offshore wind turbines.
Cordle, A.; Jonkman, J.
Aerodynamic interference between two Darrieus wind turbines
The effect of aerodynamic interference on the performance of two curved bladed Darrieus-type vertical axis wind turbines has been calculated using a vortex/lifting line aerodynamic model. The turbines have a tower-to-tower separation distance of 1.5 turbine diameters, with the line of turbine centers varying with respect to the ambient wind direction. The effects of freestream turbulence were neglected. For the cases examined, the calculations showed that the downwind turbine power decrement (1) was significant only when the line of turbine centers was coincident with the ambient wind direction, (2) increased with increasing tipspeed ratio, and (3) is due more to induced flow angularities downstream than to speed deficits near the downstream turbine.
Schatzle, P.R.; Klimas, P.C.; Spahr, H.R.
NREL: Wind Research - Small Wind Turbine Webinars
Small Wind Turbine Webinars Small Wind Turbine Webinars Here you will find webinars about small wind turbines that NREL hosted. Introducing WindLease(tm): Making Wind Energy Affordable NREL and the American Solar Energy Society (ASES) Wind Division co-hosted this webinar. (Text Version.) Date: August 1, 2013 Run Time: 40 minutes Joe Hess, VP of Business Development at United Wind, described United Wind's WindQuote and WindLease Program and explained the process from the dealer's and consumer's perspective. Texas Renewable Energy Industries Association NREL and the American Solar Energy Society (ASES) Wind Division co-hosted this webinar. (Text Version). Date: March 7, 2013 Run Time: 1 hour Russel Smith, Texas Renewable Energy Industries Association executive director and co-founder, provided an overview of the trade association
Wind Turbine Manufacturing Process Monitoring
To develop a practical inline inspection that could be used in combination with automated composite material placement equipment to economically manufacture high performance and reliable carbon composite wind turbine blade spar caps. The approach technical feasibility and cost benefit will be assessed to provide a solid basis for further development and implementation in the wind turbine industry. The program is focused on the following technology development: (1) Develop in-line monitoring methods, using optical metrology and ultrasound inspection, and perform a demonstration in the lab. This includes development of the approach and performing appropriate demonstration in the lab; (2) Develop methods to predict composite strength reduction due to defects; and (3) Develop process models to predict defects from leading indicators found in the uncured composites.
Waseem Faidi; Chris Nafis; Shatil Sinha; Chandra Yerramalli; Anthony Waas; Suresh Advani; John Gangloff; Pavel Simacek
Wind Turbine Safety and Function Test Report for the Gaia-Wind 11-kW Wind Turbine
This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers to wind energy expansion by providing independent testing results for small wind turbines (SWT). In total, four turbines were tested at the National Wind Technology Center (NWTC) as a part of this project. Safety and function testing is one of up to five tests performed on the turbines, including power performance, duration, noise, and power-quality tests. The results of the testing provide the manufacturers with reports that can be used for small wind turbine certification. The test equipment includes a Gaia-Wind 11-kW wind turbine mounted on an 18-m monopole tower. Gaia-Wind Ltd. manufactured the turbine in Denmark. The system was installed by the NWTC site operations group with guidance and assistance from Gaia-Wind.
User's manual for the vertical axis wind turbine performance computer code darter
The computer code DARTER (DARrieus, Turbine, Elemental Reynolds number) is an aerodynamic performance/loads prediction scheme based upon the conservation of momentum principle. It is the latest evolution in a sequence which began with a model developed by Templin of NRC, Canada and progressed through the Sandia National Laboratories-developed SIMOSS (SSImple MOmentum, Single Streamtube) and DART (SARrieus Turbine) to DARTER.
Klimas, P. C.; French, R. E.
Cooperative field test program for wind energy systems: Effects of precipitation on wind turbine performance. Detailed test plan and quality assurance plan
The purpose of this research is to examine the effect of precipitation on wind turbine performance. This study will be conducted at the Whisky Run windfarm on the southern Oregon coast. Precipitation has been shown to cause significant degradation in the performance of the MOD-O wind turbine by Corrigan and DeMiglio (1985), who found performance reductions of up to 20% for light rainfall, 30% for moderate rainfall and 36% for snow and drizzle. There are several penalties due to rainfall, but it appears that most of the performance degradation is due to rain induced roughness. The Whisky Run windfarm receives around 60 inches of rain per year most of which occurs from October through April. During the summer months drizzle is an occasional weather phenomena. Pacific Wind Energy (PWE) and Pacific Power and Light (PP&L) propose to examine the effect of precipitation on wind turbine performance. The Whisky Run windfarm is unique among windfarms because the power sales contract is set up such that the wind farm is considered a research project and the participants have agreed to engage in research that will benefit the industry. PP&L will be providing all of the instrumentation except for the recording rate of rain gage. PWE will be performing the analysis of the data and project management.
Wind Turbine Safety and Function Test Report for the Mariah Windspire Wind Turbine
This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers to wind energy expansion by providing independent testing results for small wind turbines (SWT). In total, five turbines were tested at the National Wind Technology Center (NWTC) as a part of this project. Safety and function testing is one of up to five tests performed on the turbines, including power performance, duration, noise, and power-quality tests. NWTC testing results provide manufacturers with reports that may be used to meet part of small wind turbine certification requirements. The test equipment includes a Mariah Windspire wind turbine mounted on a monopole tower. L&E Machine manufactured the turbine in the United States. The inverter was manufactured separately by Technology Driven Products in the United States. The system was installed by the NWTC site operations group with guidance and assistance from Mariah Power.
Wind Turbine Basics | Department of Energy
Wind Turbine Basics Wind Turbine Basics Wind Turbine Basics July 30, 2013 - 2:58pm Addthis Energy 101: Wind Turbines Basics This video explains the basics of how wind turbines operate to produce clean power from an abundant, renewable resource-the wind. Text Version Wind turbine assembly Although all wind turbines operate on similar principles, several varieties are in use today. These include horizontal axis turbines and vertical axis turbines. Horizontal Axis Turbines Horizontal axis turbines are the most common turbine configuration used today. They consist of a tall tower, atop which sits a fan-like rotor that faces into or away from the wind, a generator, a controller, and other components. Most horizontal axis turbines built today are two- or three-bladed. Horizontal axis turbines sit high atop towers to take advantage of the
Applications: Wind turbine structural health
of turbine system management. The data obtained from this multi-scale sensing capability will be fullyCapability Applications: Wind turbine structural health monitoring Individual turbine maintenance for active control in the field Limit damage propagation and maintenance costs Maximize return
Sliding mode control law for a variable speed wind turbine
Modern wind turbines are designed in order to work in variable speed operations. To perform this task, wind turbines are provided with adjustable speed generators, like the double feed induction generator. One of the main advantage of adjustable speed ... Keywords: modeling and simulation, variable structure control, wind turbine control
Oscar Barambones; Jose Maria Gonzalez De Durana; Patxi Alkorta; Jose Antonio Ramos; Manuel De La Sen
Stochastic Analysis of Wind Turbine Power Curves Edgar Anahua
procedure (IEC 61400-12) for power performance charac- terization of a single wind turbines is shown by the standard IEC 61400-12 3 [12]. In this standard procedure the power curve of a single wind turbine of the blade pitch angle system of a wind turbine [9]. The phase averaged P(t,t ) function depends on the time
Peinke, Joachim
Active load control techniques for wind turbines.
This report provides an overview on the current state of wind turbine control and introduces a number of active techniques that could be potentially used for control of wind turbine blades. The focus is on research regarding active flow control (AFC) as it applies to wind turbine performance and loads. The techniques and concepts described here are often described as 'smart structures' or 'smart rotor control'. This field is rapidly growing and there are numerous concepts currently being investigated around the world; some concepts already are focused on the wind energy industry and others are intended for use in other fields, but have the potential for wind turbine control. An AFC system can be broken into three categories: controls and sensors, actuators and devices, and the flow phenomena. This report focuses on the research involved with the actuators and devices and the generated flow phenomena caused by each device.
van Dam, C.P. (University of California, Davis, CA); Berg, Dale E.; Johnson, Scott J. (University of California, Davis, CA)
66 IEEE TRANSACTIONS ON SUSTAINABLE ENERGY, VOL. 1, NO. 2, JULY 2010 Optimization of Wind Turbine Performance With
66 IEEE TRANSACTIONS ON SUSTAINABLE ENERGY, VOL. 1, NO. 2, JULY 2010 Optimization of Wind Turbine, torque, tower acceleration, wind turbine vibrations. I. INTRODUCTION I NTEREST in renewable energy has to carbon taxation has become a catalyst in the quest for clean energy. Wind energy has been most
Kusiak, Andrew
Turbine Basics Turbine Basics Wind Turbine Basics July 30, 2013 - 2:58pm Addthis Energy 101: Wind Turbines Basics This video explains the basics of how wind turbines operate to produce clean power from an abundant, renewable resource-the wind. Text Version Wind turbine assembly Although all wind turbines operate on similar principles, several varieties are in use today. These include horizontal axis turbines and vertical axis turbines. Horizontal Axis Turbines Horizontal axis turbines are the most common turbine configuration used today. They consist of a tall tower, atop which sits a fan-like rotor that faces into or away from the wind, a generator, a controller, and other components. Most horizontal axis turbines built today are two- or three-bladed. Horizontal axis turbines sit high atop towers to take advantage of the
Wind turbine rotor aileron
A wind turbine has a rotor with at least one blade which has an aileron which is adjusted by an actuator. A hinge has two portions, one for mounting a stationary hinge arm to the blade, the other for coupling to the aileron actuator. Several types of hinges can be used, along with different actuators. The aileron is designed so that it has a constant chord with a number of identical sub-assemblies. The leading edge of the aileron has at least one curved portion so that the aileron does not vent over a certain range of angles, but vents if the position is outside the range. A cyclic actuator can be mounted to the aileron to adjust the position periodically. Generally, the aileron will be adjusted over a range related to the rotational position of the blade. A method for operating the cyclic assembly is also described.
Coleman, Clint (Warren, VT); Kurth, William T. (Warren, VT)
Field Measurements of Wind Turbine Wakes with Lidars
Field measurements of the wake flow produced from a 2-MW Enercon E-70 wind turbine were performed using three scanning Doppler wind lidars. A GPS-based technique was used to determine the position of the wind turbine and the wind lidar locations, ...
Giacomo Valerio Iungo; Yu-Ting Wu; Fernando Port�-Agel
Wind Turbine Generator System Power Quality Test Report for the Gaia Wind 11-kW Wind Turbine
This report details the power quality test on the Gaia Wind 11-kW Wind Turbine as part of the U.S. Department of Energy's Independent Testing Project. In total five turbines are being tested as part of the project. Power quality testing is one of up to five test that may be performed on the turbines including power performance, safety and function, noise, and duration tests. The results of the testing provide manufacturers with reports that may be used for small wind turbine certification.
Curtis, A.; Gevorgian, V.
Wind Turbine Generator System Duration Test Report for the Mariah Power Windspire Wind Turbine
This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, five turbines are being tested at the National Wind Technology Center (NWTC) as a part of the first round of this project. Duration testing is one of up to five tests that may be performed on the turbines. Other tests include power performance, safety and function, noise, and power quality tests. NWTC testing results provide manufacturers with reports that may be used to meet part of small wind turbine certification requirements. This duration test report focuses on the Mariah Power Windspire wind turbine.
Wind Turbine Safety and Function Test Report for the ARE 442 Wind Turbine
This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, four turbines were tested at the National Wind Technology Center (NWTC) as a part of this project. Safety and function testing is one of up to five tests that were performed on the turbines, including power performance, duration, noise, and power quality tests. Test results provide manufacturers with reports that can be used for small wind turbine certification. The test equipment includes an ARE 442 wind turbine mounted on a 100-ft free-standing lattice tower. The system was installed by the NWTC Site Operations group with guidance and assistance from Abundant Renewable Energy.
van Dam, J.; Baker, D.; Jager, D.
Onshore Wind Turbines Life Extension
Wind turbines are currently type-certified for nominal 20-year design lives, but many wind industry stakeholders are considering the possibility of extending the operating lives of their projects by 5, 10, or 15 years. Life extension�the operation of an asset beyond the nominal design life�is just one option to maximize the financial return of these expensive assets. Other options include repowering, upgrading, or uprating a turbine.In order to make informed decisions ...
Parametric design of floating wind turbines
As the price of energy increases and wind turbine technology matures, it is evident that cost effective designs for floating wind turbines are needed. The next frontier for wind power is the ocean, yet development in near ...
Tracy, Christopher (Christopher Henry)
Load attenuating passively adaptive wind turbine blade
A method and apparatus for improving wind turbine performance by alleviating loads and controlling the rotor. The invention employs the use of a passively adaptive blade that senses the wind velocity or rotational speed, and accordingly modifies its aerodynamic configuration. The invention exploits the load mitigation prospects of a blade that twists toward feather as it bends. The invention includes passively adaptive wind turbine rotors or blades with currently preferred power control features. The apparatus is a composite fiber horizontal axis wind-turbine blade, in which a substantial majority of fibers in the blade skin are inclined at angles of between 15 and 30 degrees to the axis of the blade, to produces passive adaptive aeroelastic tailoring (bend-twist coupling) to alleviate loading without unduly jeopardizing performance.
Veers, Paul S. (Albuquerque, NM); Lobitz, Donald W. (Albuquerque, NM)
Subhourly wind forecasting techniques for wind turbine operations
Three models for making automated forecasts of subhourly wind and wind power fluctuations were examined to determine the models' appropriateness, accuracy, and reliability in wind forecasting for wind turbine operation. Such automated forecasts appear to have value not only in wind turbine control and operating strategies, but also in improving individual wind turbine control and operating strategies, but also in improving individual wind turbine operating strategies (such as determining when to attempt startup). A simple persistence model, an autoregressive model, and a generalized equivalent Markhov (GEM) model were developed and tested using spring season data from the WKY television tower located near Oklahoma City, Oklahoma. The three models represent a pure measurement approach, a pure statistical method and a statistical-dynamical model, respectively. Forecasting models of wind speed means and measures of deviations about the mean were developed and tested for all three forecasting techniques for the 45-meter level and for the 10-, 30- and 60-minute time intervals. The results of this exploratory study indicate that a persistence-based approach, using onsite measurements, will probably be superior in the 10-minute time frame. The GEM model appears to have the most potential in 30-minute and longer time frames, particularly when forecasting wind speed fluctuations. However, several improvements to the GEM model are suggested. In comparison to the other models, the autoregressive model performed poorly at all time frames; but, it is recommended that this model be upgraded to an autoregressive moving average (ARMA or ARIMA) model. The primary constraint in adapting the forecasting models to the production of wind turbine cluster power output forecasts is the lack of either actual data, or suitable models, for simulating wind turbine cluster performance.
Wegley, H.L.; Kosorok, M.R.; Formica, W.J.
Vertical axis wind turbine control strategy
Early expensive in automatic operation of the Sandia 17-m vertical axis research wind turbine (VAWT) has demonstrated the need for a systematic study of control algorithms. To this end, a computer model has been developed that uses actual wind time series and turbine performance data to calculate the power produced by the Sandia 17-m VAWT operating in automatic control. The model has been used to investigate the influence of starting algorithms on annual energy production. The results indicate that, depending on turbine and local wind characteristics, a bad choice of a control algorithm can significantly reduce overall energy production. The model can be used to select control algorithms and threshold parameters that maximize long-term energy production. An attempt has been made to generalize these results from local site and turbine characteristics to obtain general guidelines for control algorithm design.
McNerney, G.M.
An experimental and numerical study of wind turbine seismic behavior
3.2.1 Description of Test Wind Turbine . . . . . .Figure 1.2: Components of a modern wind turbine . . . . . .Wind Turbine . . . . . . . . . . . . . . . . . . . . . . .
Prowell, I.
Gamesa Wind Turbines Pvt Ltd | Open Energy Information
Turbines Pvt Ltd Jump to: navigation, search Name Gamesa Wind Turbines Pvt. Ltd. Place Chennai, Tamil Nadu, India Sector Wind energy Product Chennai-based wind turbine...
NREL: Wind Research - Small Wind Turbine Independent Testing
Wind Research Search More Search Options Site Map Printable Version Small Wind Turbine Independent Testing One of the barriers for the small wind market has been the lack...
Airfoils for the tip and mid-span regions of a wind turbine blade have upper surface and lower surface shapes and contours between a leading edge and a trailing edge that minimize roughness effects of the airfoil and provide maximum lift coefficients that are largely insensitive to roughness effects. The airfoil in one embodiment is shaped and contoured to have a thickness in a range of about fourteen to seventeen percent, a Reynolds number in a range of about 1,500,000 to 2,000,000, and a maximum lift coefficient in a range of about 1.4 to 1.5. In another embodiment, the airfoil is shaped and contoured to have a thickness in a range of about fourteen percent to sixteen percent, a Reynolds number in a range of about 1,500,000 to 3,000,000, and a maximum lift coefficient in a range of about 0.7 to 1.5. Another embodiment of the airfoil is shaped and contoured to have a Reynolds in a range of about 1,500,000 to 4,000,000, and a maximum lift coefficient in a range of about 1.0 to 1.5.
Energy 101: Wind Turbines | Department of Energy
Wind Turbines Wind Turbines Energy 101: Wind Turbines Addthis Description See how wind turbines generate clean electricity from the power of the wind. Highlighted are the various parts and mechanisms of a modern wind turbine. Duration 2:16 Topic Tax Credits, Rebates, Savings Wind Energy Economy Credit Energy Department Video MR. : We've all seen those creaky old windmills on farms, and although they may seem about as low-tech as you can get, those old windmills are the predecessors for new modern wind turbines that generate electricity. The same wind that used to pump water for cattle is now turning giant wind turbines to power cities and homes. OK, have a look at this wind farm in the California desert, a hot desert next to tall mountains - an ideal place for a lot of wind.
APPENDIX A MEASURING IMPACTS TO BIRDS CAUSED BY WIND TURBINES #12;A-1 APPENDIX A MEASURING IMPACTS TO BIRDS CAUSED BY WIND TURBINES 1.0 INTRODUCTION Differential composition of wind turbines at wind energy used is the number of fatalities per wind turbine per year (Anderson et al. 1999). This metric has
Wind Turbine Generator System Duration Test Report for the ARE 442 Wind Turbine
This test is being conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, four turbines are being tested at the NWTC as a part of this project. Duration testing is one of up to 5 tests that may be performed on the turbines, including power performance, safety and function, noise, and power quality tests. The results of the testing provide manufacturers with reports that may be used for small wind turbine certification. The test equipment includes a grid connected ARE 442 wind turbine mounted on a 30.5 meter (100 ft) lattice tower manufactured by Abundant Renewable Energy. The system was installed by the NWTC Site Operations group with guidance and assistance from Abundant Renewable Energy.
Wind Turbines Electrical and Mechanical Engineering
Wind Turbines Electrical and Mechanical Engineering Objective · Introduce students to the concept of alternative energy. · Explain the math and scientific principles behind engineering wind turbines. Standards and how it applies to wind energy · About how surface area and shape effects wind turbine efficiency
Provancher, William
Applications: Wind turbine and blade design
Capability Applications: Wind turbine and blade design optimization Energy production enhancement Summary: As the wind energy industry works to provide the infra- structure necessary for wind turbine develops a means to aug- ment power production with wind-derived energy. Turbines have become massive
Offshore Wind Turbines and Their Installation
Offshore winds tend to be higher, more constant and not disturbed by rough terrain, so there is a large potential for utilizing wind energy near to the sea. Compared with the wind energy converters onland, wind turbine components offshore will subject ... Keywords: renewable energy, wind power generation, offshore wind turbines, offshore installation
Liwei Li; Jianxing Ren
Using Neural Networks to Estimate Wind Turbine
This paper uses data collected at Central and South West Services Fort Davis wind farm to develop a neural network based prediction of power produced by each turbine. The power generated by electric wind turbines changes rapidly because of the continuous fluctuation of wind speed and direction. It is important for the power industry to have the capability to perform this prediction for diagnostic purposes---lower-than-expected wind power may be an early indicator of a need for maintenance. In this paper, characteristics of wind power generation are first evaluated in order to establish the relative importance for the neural network. A four input neural network is developed and its performance is shown to be superior to the single parameter traditional model approach.
Power Generation Shuhui; Shuhui Li; Donald C. Wunsch; Edgar A. O�hair; Michael G. Giesselmann; Senior Member; Senior Member
Wind Turbines Wind Turbines Energy 101: Wind Turbines Addthis Below is the text version for the Energy 101: Wind Turbines video. The video opens with "Energy 101: Wind Turbines." This is followed by wooden windmills on farms. We've all seen those creaky, old windmills on farms. And although they may seem about as low-tech as you can get, those old windmills are the predecessors for new, modern wind turbines that generat electricity. The video pans through shots of large windmills and wind farms of different sizes, situated on cultivated plains and hills. The same wind that used to pump water for cattle is now turning giant wind turbines to power cities and homes. OK, have a look at this wind farm in the California desert. A hot desert, next to tall mountains. An ideal place for a lot of wind.
Maglev Wind Turbine Technologies | Open Energy Information
Maglev Wind Turbine Technologies Maglev Wind Turbine Technologies Jump to: navigation, search Name Maglev Wind Turbine Technologies Place Sierra Vista, Arizona Zip 85635 Sector Wind energy Product The new company employs magnetic levitation (Maglev) technology in its wind turbines, which it says will have a longer life span, be cheaper to build, and produce 1GW of energy each. References Maglev Wind Turbine Technologies[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Maglev Wind Turbine Technologies is a company located in Sierra Vista, Arizona . References ↑ "Maglev Wind Turbine Technologies" Retrieved from "http://en.openei.org/w/index.php?title=Maglev_Wind_Turbine_Technologies&oldid=348578"
Wind Turbine Generator System Acoustic Noise Test Report for the ARE 442 Wind Turbine
This test was conducted on the ARE 442 as part of the U.S. Department of Energy's (DOE's) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, five turbines are being tested at the National Wind Technology Center (NWTC) as a part of this project. Acoustic noise testing is one of up to five tests that may be performed on the turbines, including duration, safety and function, power performance, and power quality tests. The acoustic noise test was conducted to the IEC 61400-11 Edition 2.1.
Huskey, A.; van Dam, J.
Wind and solar powered turbine
A power generating station having a generator driven by solar heat assisted ambient wind is disclosed. A first plurality of radially extending air passages direct ambient wind to a radial flow wind turbine disposed in a centrally located opening in a substantially disc-shaped structure. A solar radiation collecting surface having black bodies is disposed above the first plurality of air passages and in communication with a second plurality of radial air passages. A cover plate enclosing the second plurality of radial air passages is transparent so as to permit solar radiation to effectively reach the black bodies. The second plurality of air passages direct ambient wind and thermal updrafts generated by the black bodies to an axial flow turbine which also derives additional motive power from the air mass exhausted by the radial flow turbine. The rotating shaft of the turbines drive the generator. The solar and wind driven power generating system operates in electrical cogeneration mode with a fuel powered prime mover. The system is particularly adapted to satisfy the power requirements of a relatively small community located in a geographic area having favorable climatic conditions for wind and solar powered power generation.
Wells, I.D.; Holmes, M.; Kohn, J.L.
NREL: Wind Research - Advanced Research Turbines
Research Turbines Two 440 foot meteorological towers are upwind of two research wind turbines. Two 600-kW Westinghouse turbines at the NWTC are used to test new control...
Virtual Wind Speed Sensor for Wind Turbines Andrew Kusiak1
Virtual Wind Speed Sensor for Wind Turbines Andrew Kusiak1 ; Haiyang Zheng2 ; and Zijun Zhang3 Abstract: A data-driven approach for development of a virtual wind-speed sensor for wind turbines is presented. The virtual wind-speed sensor is built from historical wind-farm data by data-mining algorithms
Vertical axis wind turbine airfoil
A vertical axis wind turbine airfoil is described. The wind turbine airfoil can include a leading edge, a trailing edge, an upper curved surface, a lower curved surface, and a centerline running between the upper surface and the lower surface and from the leading edge to the trailing edge. The airfoil can be configured so that the distance between the centerline and the upper surface is the same as the distance between the centerline and the lower surface at all points along the length of the airfoil. A plurality of such airfoils can be included in a vertical axis wind turbine. These airfoils can be vertically disposed and can rotate about a vertical axis.
Krivcov, Vladimir; Krivospitski, Vladimir; Maksimov, Vasili; Halstead, Richard; Grahov, Jurij Vasiljevich
Siting guidelines for utility application of wind turbines. Final report
Utility-oriented guidelines are described for identifying viable sites for wind turbines. Topics and procedures are also discussed that are important in carrying out a wind turbine siting program. These topics include: a description of the Department of Energy wind resource atlases; procedures for predicting wind turbine performance at potential sites; methods for analyzing wind turbine economics; procedures for estimating installation and maintenance costs; methods for anlayzing the distribution of wind resources over an area; and instrumentation for documenting wind behavior at potential sites. The procedure described is applicable to small and large utilities. Although the procedure was developed as a site-selection tool, it can also be used by a utility who wishes to estimate the potential for wind turbine penetration into its future generation mix.
Pennell, W.T.
Wind Turbine Productivity Improvement and Procurement Guidelines
Proper selection of equipment specifications during wind turbine procurement and careful operation and maintenance procedures are keys to maximizing wind project availability and annual energy generation and revenues.
Structural Health Monitoring of Wind Turbine Blades
Presentation Title, Structural Health Monitoring of Wind Turbine Blades. Author(s) ... is mandatory for the cost-effective operation of an offshore wind power plant.
Wind Tunnel Aerodynamic Tests of Six Airfoils for Use on Small Wind Turbines; Period of Performance: October 31, 2002--January 31, 2003
Wind Tunnel Aerodynamic Tests of Six Airfoils for Use on Small Wind Turbinesrepresents the fourth installment in a series of volumes documenting the ongoing work of th University of Illinois at Urbana-Champaign Low-Speed Airfoil Tests Program. This particular volume deals with airfoils that are candidates for use on small wind turbines, which operate at low Reynolds numbers.
Selig, M. S.; McGranahan, B. D.
AWEA Small Wind Turbine Global Market Study
wind turbines those with rated capacities of 100 kilowatts (kW)1 and less grew 15% in 2009 with 20 small wind turbines, 95 of which-- more than one-third--are based in the u.S. An estimated 100,000 unitsAWEA Small Wind Turbine Global Market Study YEAR ENDING 2009 #12;Summary 3 Survey Findings
Offshore Wind Turbines: Some Technical Challenges
1 Offshore Wind Turbines: Some Technical Challenges Prof. Guy Houlsby FREng Oxford University House engineers concerned with installation of offshore wind turbines. The author is Professor of Civil solved, a DTI and EPSRC-sponsored research programme on foundations for wind turbines will be briefly
Houlsby, Guy T.
Condition Monitoring of Wind Turbines
Based on industry experience, after four years of operation, failures of wind turbine gearboxes, generators, and other major components become common, and each failure typically requires major repairs and/or component replacement. Wind project owners and operators who apply lube oil monitoring, vibration-signature analysis, and other condition monitoring technology can expect to detect subtle changes in machine condition that often lead to major failures if left unrepaired. The estimated cost savings of ...
Wind shear climatology for large wind turbine generators
Climatological wind shear analyses relevant to the design and operation of multimegawatt wind turbines are provided. Insight is provided for relating the wind experienced by a rotating blade in a shear flow to the analysis results. A simple analysis of the wind experienced by a rotating blade for three types of wind shear profiles under steady-state conditions is presented in graphical form. Comparisons of the magnitude and frequency of the variations in 1) the wind sensed by a single blade element, 2) the sum, and 3) the difference of the winds sensed by opposite blade elements show strong sensitivity to profile shape. These three items represent forcing functions that can be related to 1) flatwise bending moment, 2) torque on the shaft, and 3) teeter angle. A computer model was constructed to simulate rotational sampling of 10-s sampled winds from a tall tower for three different types of large wind turbines. Time series produced by the model indicated that the forcing functions on a rotating blade vary according to the shear profile encountered during each revolution as opposed to a profile derived from average wind conditions, e.g., hourly average winds. An analysis scheme was developed to establish a climatology of wind shear profiles derived from 10-s sampled winds and hourly average winds measured over a one-year period at several levels on a tall tower. Because of the sensitivity of the forcing function variability to profile shape, the analyses performed and presented are in the form of joint frequency distributions of velocity differences of the the top-to-hub versus the hub-to-bottom portion of disks of rotation for the three turbine configurations.
Elliott, D.L.; Wendell, L.L.; Heflick, S.K.
NREL: Wind Research - Case Study: Burke Mountain Wind Turbine...
composting program, and encouraging visitors to recycle whenever possible. Wind Powering America verified the following wind turbine project facts with Hannah Collins from...
Small Wind Turbine Testing and Applications Development
Small wind turbines offer a promising alternative for many remote electrical uses where there is a good wind resource. The National Wind Technology Center (NWTC) of the National Renewable Energy Laboratory helps further the role that small turbines can play in supplying remote power needs. The NWTC tests and develops new applications for small turbines. The NWTC also develops components used in conjunction with wind turbines for various applications. This paper describes wind energy research at the NWTC for applications including battery charging stations, water desalination/purification, and health clinics. Development of data acquisition systems and tests on small turbines are also described.
Corbus, D.; Baring-Gould, I.; Drouilhet, S.; Gevorgian, V.; Jimenez, T.; Newcomb, C.; Flowers, L.
Wind Turbine Generator System Duration Test Report for the Gaia-Wind 11 kW Wind Turbine
This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, five turbines are being tested at the National Renewable Energy Laboratory's (NRELs) National Wind Technology Center (NWTC) as a part of this project. Duration testing is one of up to five tests that may be performed on the turbines, including power performance, safety and function, noise, and power quality tests. The results of the testing will provide the manufacturers with reports that may be used for small wind turbine certification. The test equipment includes a Gaia-Wind 11 kW wind turbine mounted on an 18 m monopole tower. Gaia-Wind Ltd. manufactured the turbine in Denmark, although the company is based in Scotland. The system was installed by the NWTC Site Operations group with guidance and assistance from Gaia-Wind.
Blade Offset and Pitch Effects on a High Solidity Vertical Axis Wind Turbine
ABSTRACT A high solidity, small scale, 2.5m diameter by 3m high Vertical Axis Wind Turbine (VAWT, performance 1. INTRODUCTION Small scale vertical axis wind turbines (VAWTs) show potential for urban rooftop turbines. Keywords: Vertical Axis Wind Turbine, VAWT, airfoil, pitch, blade, mount, offset, high solidity
Stakeholder Engagement and Outreach: Siting Wind Turbines
Wind Powering America (EERE)
Resources & Tools Resources & Tools Siting Wind Turbines Wind Powering America works to increase deployment of wind energy. This page provides resources about wind turbine siting. American Wind Wildlife Institute The American Wind Wildlife Institute (AWWI) facilitates timely and responsible development of wind energy, while protecting wildlife and wildlife habitat. AWWI was created and is sustained by a unique collaboration of environmentalists, conservationists, state wildlife agencies, and wind industry leaders. Its purpose is to help lay the scientific groundwork and best practices for wind farm siting and operations, through targeted initiatives: wind-wildlife research, landscape assessment, mitigation, and education. Ordinances Regulating Development of Commercial Wind Energy Facilities
Analysis of the effects of integrating wind turbines into a conventional utility: a case study. Final report
The impact on a utility incorporating wind turbine generation due to wind speed sampling frequency, wind turbine performance model, and wind speed forecasting accuracy is examined. The utility analyzed in the study was the Los Angeles Department of Water and Power and the wind turbine assumed was the MOD-2. The sensitivity of the economic value of wind turbine generation to wind speed sampling frequency and wind turbine modeling technique is examined as well as the impact of wind forecasting accuracy on utility operation and production costs. Wind speed data from San Gorgonio Pass, California during 1979 are used to estimate wind turbine performance using four different simulation methods. (LEW)
Goldenblatt, M.K.; Wegley, H.L.; Miller, A.H.
Analysis of the effects of integrating wind turbines into a conventional utility: a case study. Revised final report
The impact on a utility incorporating wind turbine generation due to wind speed sampling frequency, wind turbine performance model, and wind speed forecasting accuracy is examined. The utility analyzed in this study was the Los Angeles Department of Water and Power, and the wind turbine assumed was the MOD-2. The sensitivity of the economic value of wind turbine generation to wind speed sampling frequency and wind turbine modeling technique is examined as well as the impact of wind forecasting accuracy on utility operation and production costs. Wind speed data from San Gorgonio Pass, California during 1979 are used to estimate wind turbine performance using four different simulation methods. (LEW)
The Estimation of Wind Turbine Pitch Angle Based on ANN
Variable-speed and constant-frequency (VSCF) pitch-controlled wind turbine is believed to be superior to other types of wind turbine due to its features such as high efficiency and ideal starting and braking performance, Artificial Neural Networks (ANN) ... Keywords: VSCF, ANN, pitch angle, Pitch-controlled system
Yanping Liu; Shuhong Liu; Hongmei Guo; Huajun Wang
Definition: Wind turbine | Open Energy Information
turbine turbine Jump to: navigation, search Dictionary.png Wind turbine A machine that converts wind energy to mechanical energy; typically connected to a generator to produce electricity.[1][2] View on Wikipedia Wikipedia Definition A wind turbine is a device that converts kinetic energy from the wind, also called wind energy, into mechanical energy in a process known as wind power. If the mechanical energy is used to produce electricity, the device may be called a wind turbine or wind power plant. If the mechanical energy is used to drive machinery, such as for grinding grain or pumping water, the device is called a windmill or wind pump. Similarly, it may be referred to as a wind charger when used for charging batteries. The result of over a millennium of windmill development and modern engineering,
Method and apparatus for wind turbine air gap control - Energy ...
Methods and apparatus for assembling a wind turbine generator are provided. The wind turbine generator includes a core and a plurality of stator windings ...
NREL: Learning - Wind Energy Basics: How Wind Turbines Work
Wind Energy Basics: How Wind Turbines Work Wind Energy Basics: How Wind Turbines Work We have been harnessing the wind's energy for hundreds of years. From old Holland to farms in the United States, windmills have been used for pumping water or grinding grain. Today, the windmill's modern equivalent-a wind turbine-can use the wind's energy to generate electricity. Wind turbines, like windmills, are mounted on a tower to capture the most energy. At 100 feet (30 meters) or more aboveground, they can take advantage of the faster and less turbulent wind. Turbines catch the wind's energy with their propeller-like blades. Usually, two or three blades are mounted on a shaft to form a rotor. A blade acts much like an airplane wing. When the wind blows, a pocket of low-pressure air forms on the downwind side of the blade. The low-pressure
Dynamic Models for Wind Turbines and Wind Power Plants
The primary objective of this report was to develop universal manufacturer-independent wind turbine and wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Manufacturer-specific models of wind turbines are favored for use in wind power interconnection studies. While they are detailed and accurate, their usages are limited to the terms of the non-disclosure agreement, thus stifling model sharing. The primary objective of the work proposed is to develop universal manufacturer-independent wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Each of these models includes representations of general turbine aerodynamics, the mechanical drive-train, and the electrical characteristics of the generator and converter, as well as the control systems typically used. To determine how realistic model performance is, the performance of one of the models (doubly-fed induction generator model) has been validated using real-world wind power plant data. This work also documents selected applications of these models.
Singh, M.; Santoso, S.
Method and apparatus for wind turbine braking
A method for braking a wind turbine including at least one rotor blade coupled to a rotor. The method includes selectively controlling an angle of pitch of the at least one rotor blade with respect to a wind direction based on a design parameter of a component of the wind turbine to facilitate reducing a force induced into the wind turbine component as a result of braking.
Barbu, Corneliu (Laguna Hills, CA); Teichmann, Ralph (Nishkayuna, NY); Avagliano, Aaron (Houston, TX); Kammer, Leonardo Cesar (Niskayuna, NY); Pierce, Kirk Gee (Simpsonville, SC); Pesetsky, David Samuel (Greenville, SC); Gauchel, Peter (Muenster, DE)
A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic simulations
A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic of multi-megawatt turbines requires a new generation of modeling capability to assess individual turbine performance as well as detailed turbine- turbine and turbine-atmosphere interactions. Scientists
Duration Test Report for the Ventera VT10 Wind Turbine
This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small wind turbines. Five turbines were tested at the National Wind Technology Center (NWTC) at the National Renewable Energy Laboratory (NREL) as a part of round one of this project. Duration testing is one of up to five tests that may be performed on the turbines, including power performance, safety and function, noise, and power quality. Test results will provide manufacturers with reports that can be used to fulfill part of the requirements for small wind turbine certification. The test equipment included a grid-connected Ventera Energy Corporation VT10 wind turbine mounted on an 18.3-m (60-ft) self-supporting lattice tower manufactured by Rohn.
On the Fatigue Analysis of Wind Turbines
Modern wind turbines are fatigue critical machines that are typically used to produce electrical power from the wind. Operational experiences with these large rotating machines indicated that their components (primarily blades and blade joints) were failing at unexpectedly high rates, which led the wind turbine community to develop fatigue analysis capabilities for wind turbines. Our ability to analyze the fatigue behavior of wind turbine components has matured to the point that the prediction of service lifetime is becoming an essential part of the design process. In this review paper, I summarize the technology and describe the ''best practices'' for the fatigue analysis of a wind turbine component. The paper focuses on U.S. technology, but cites European references that provide important insights into the fatigue analysis of wind turbines.
Sutherland, Herbert J.
Assessment of Supervisory Control and Data Acquisition Data Mining for Wind Turbine Condition Monitoring and Performance Improvement
As the wind industry grows and matures, many of the larger wind turbines (2 MW and above) are being outfitted with sophisticated condition-monitoring systems (CMSs), supplied either by the original equipment manufacturer or through a third party to reduce failures, decrease maintenance downtime, and improve reliability. Such systems use vibration sensors in key positions and lubrication oil analysis, with costs of the hardware relatively high, and suffer from spurious alarms. The lifetime cost-benefit ra...
Wind Turbine Generator System Acoustic Noise Test Report for the Gaia Wind 11-kW Wind Turbine
This report details the acoustic noise test conducted on the Gaia-Wind 11-kW wind turbine at the National Wind Technology Center. The test turbine is a two- bladed, downwind wind turbine with a rated power of 11 kW. The test turbine was tested in accordance with the International Electrotechnical Commission standard, IEC 61400-11 Ed 2.1 2006-11 Wind Turbine Generator Systems -- Part 11 Acoustic Noise Measurement Techniques.
Huskey, A.
Wind Turbines Wind Turbines Energy 101: Wind Turbines July 30, 2010 - 10:47am Addthis John Schueler John Schueler Former New Media Specialist, Office of Public Affairs On Tuesday, the Department announced a $117 million loan guarantee through for the Kahuku Wind Power Project in Hawaii. That's a major step forward for clean energy in the region, as it's expected to supply clean electricity to roughly 7,700 households per year, and it also invites a deceptively simple question: how exactly do wind turbines generate electricity? One thing you might not realize is that wind is actually a form of solar energy. This is because wind is produced by the sun heating Earth's atmosphere, the rotation of the earth, and the earth's surface irregularities. Wind turbines are the rotary devices that convert the
WindPACT Turbine Rotor Design, Specific Rating Study; Period of Performance: June 29, 2000--March 1, 2003
In 2000, the National Renewable Energy Laboratory (NREL) launched the Wind Partnerships for Advanced Component Technologies (WindPACT) program to examine ways in which the cost of wind energy could be reduced a further 30%. One element of the WindPACT program has been a series of design studies aimed at each of the major subsystems of the wind turbine to study the effect of scale and of alternative design approaches. The WindPACT Turbine Rotor Design Study was carried out by Global Energy Concepts, LLC, (GEC) on behalf of NREL, and the final report was delivered in June 2002. The study examined what configuration and design changes in the rotor would reduce the overall cost of energy. The objectives of this report are to use the 1.5-MW baseline configuration from the earlier WindPACT Rotor Design Study to examine the effect of different power ratings and to identify an optimum specific rating; to examine the effect of different maximum tip speeds on overall cost of energy (COE); to examine the role of different wind regimes on the optimum specific rating; and to examine how the optimum specific rating may be affected by introducing more advanced blade designs.
Malcolm, D. J.; Hansen, A. C.
Offshore Wind Turbine Wakes Measured by Sodar
A ship-mounted sodar was used to measure wind turbine wakes in an offshore wind farm in Denmark. The wake magnitude and vertical extent were determined by measuring the wind speed profile behind an operating turbine, then shutting down the ...
R. J. Barthelmie; L. Folkerts; F. T. Ormel; P. Sanderhoff; P. J. Eecen; O. Stobbe; N. M. Nielsen
NREL: Wind Research - Mariah Power's Windspire Wind Turbine Testing and
Mariah Power's Windspire Wind Turbine Testing and Results Mariah Power's Windspire Wind Turbine Testing and Results A video of Mariah Power's Windspire wind turbine. Text Version As part of the National Renewable Energy Laboratory and U.S. Department of Energy (NREL/DOE) Independent Testing project, NREL tested Mariah Power's Windspire Giromill small wind turbine at the National Wind Technology Center (NWTC) through January 14, 2009 when NREL terminated its testing. Read a chronology of events and letter from Mariah Power to NREL. The Windspire is a 1.2-kilowatt (kW) vertical-axis small wind turbine. The turbine tower is 9.1 meters tall, and its rotor area is 1.2 by 6.1 meters. The turbine has a permanent-magnet generator with a single-phase output at 120 volts AC. Testing Summary Testing was terminated January 14, 2009. Published test reports include
Offshore Wind Turbines Estimated Noise from Offshore Wind Turbine, Monhegan Island, Maine Addendum 2
Additional modeling for offshore wind turbines, for proposed floating wind platforms to be deployed by University of Maine/DeepCwind.
Aker, Pamela M.; Jones, Anthony M.; Copping, Andrea E.
Small Wind Research Turbine: Final Report
The Small Wind Research Turbine (SWRT) project was initiated to provide reliable test data for model validation of furling wind turbines and to help understand small wind turbine loads. This report will familiarize the user with the scope of the SWRT test and support the use of these data. In addition to describing all the testing details and results, the report presents an analysis of the test data and compares the SWRT test data to simulation results from the FAST aeroelastic simulation model.
Corbus, D.; Meadors, M.
Stakeholder Engagement and Outreach: Wind Turbine Ordinances
Information Information Resources Printable Version Bookmark and Share Publications Success Stories Webinars Podcasts Videos Stakeholder Interviews Lessons Learned Wind Working Groups Economic Impact Studies Wind Turbine Ordinances Wind Turbine Ordinances This page lists 135 state and local wind turbine ordinances. State and local governments and policymakers can use this collection of example wind turbine ordinances when drafting a new wind energy ordinance in a town or county without existing ordinances. Due to increasing energy demands in the United States and more installed wind projects, rural communities and local governments with limited or no experience with wind energy now have the opportunity to become involved in this industry. Communities with good wind resources may be approached by
Duration Test Report for the SWIFT Wind Turbine
This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. Three turbines where selected for testing at the National Wind Technology Center (NWTC) as a part of round two of the Small Wind Turbine Independent Testing project. Duration testing is one of up to 5 tests that may be performed on the turbines. Other tests include power performance, safety and function, noise, and power quality. The results of the testing will provide the manufacturers with reports that may be used for small wind turbine certification.
Safety and Function Test Report for the SWIFT Wind Turbine
This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. Three turbines where selected for testing at the National Wind Technology Center (NWTC) as a part of round two of the Small Wind Turbine Independent Testing project. Safety and Function testing is one of up to 5 tests that may be performed on the turbines. Other tests include power performance, duration, noise, and power quality. The results of the testing will provide the manufacturers with reports that may be used for small wind turbine certification.
Modelling and control of large wind turbine.
?? In order to make the wind energy an economical alternative for energy production, upscaling of turbine to 10 - 15MW may be necessary to� (more)
zafar, syed hammad
Wind Turbine Design Innovations Drive Industry Transformation...
Wind Turbine Design Innovations Drive Industry Transformation For more than 20 years, the National Renewable Energy Laboratory (NREL) has helped GE and its predecessors achieve...
The Economic Optimization of Wind Turbine Design .
??This thesis studies the optimization of a variable speed, three blade, horizontal-axis wind turbine. The design parameters considered are the rotor diameter, hub height and� (more)
Schmidt, Michael Frank
Improving Wind Turbine Gearbox Reliability: Preprint
This paper describes a new research and development initiative to improve gearbox reliability in wind turbines begun at the National Renewable Energy Laboratory (NREL) in Golden, Colorado, USA.
Musial, W.; Butterfield, S.; McNiff, B.
A modern Danish 600 kW wind turbine will recover all the energy spent in its manufacture, maintenance, and scrapping within some three months of its commissioning.
Turbine Inflow Characterization at the National Wind Technology Center: Preprint
Utility-scale wind turbines operate in dynamic flows that can vary significantly over timescales from less than a second to several years. To better understand the inflow to utility-scale turbines, two inflow towers were installed and commissioned at the National Renewable Energy Laboratory's (NREL) National Wind Technology Center near Boulder, Colorado, in 2011. These towers are 135 m tall and instrumented with a combination of sonic anemometers, cup anemometers, wind vanes, and temperature measurements to characterize the inflow wind speed and direction, turbulence, stability and thermal stratification to two utility-scale turbines. Herein, we present variations in mean and turbulent wind parameters with height, atmospheric stability, and as a function of wind direction that could be important for turbine operation as well as persistence of turbine wakes. Wind speed, turbulence intensity, and dissipation are all factors that affect turbine performance. Our results shown that these all vary with height across the rotor disk, demonstrating the importance of measuring atmospheric conditions that influence wind turbine performance at multiple heights in the rotor disk, rather than relying on extrapolation from lower levels.
Clifton, A.; Schreck, S.; Scott, G.; Kelley, N.; Lundquist, J.
Turbine Inflow Characterization at the National Wind Technology Center
Utility-scale wind turbines operate in dynamic flows that can vary significantly over timescales from less than a second to several years. To better understand the inflow to utility-scale turbines, two inflow towers were installed and commissioned at the National Renewable Energy Laboratory's (NREL) National Wind Technology Center near Boulder, Colorado, in 2011. These towers are 135 m tall and instrumented with a combination of sonic anemometers, cup anemometers, wind vanes, and temperature measurements to characterize the inflow wind speed and direction, turbulence, stability and thermal stratification to two utility-scale turbines. Herein, we present variations in mean and turbulent wind parameters with height, atmospheric stability, and as a function of wind direction that could be important for turbine operation as well as persistence of turbine wakes. Wind speed, turbulence intensity, and dissipation are all factors that affect turbine performance. Our results show that these all vary with height across the rotor disk, demonstrating the importance of measuring atmospheric conditions that influence wind turbine performance at multiple heights in the rotor disk, rather than relying on extrapolation from lower levels.
Clifton, A.; Schreck, S.; Scott, G.; Kelley, N.; Lundquist, J. K.
Wind Turbine Generator System Safety and Function Test Report for the Entegrity EW50 Wind Turbine
This report summarizes the results of a safety and function test that NREL conducted on the Entegrity EW50 wind turbine. This test was conducted in accordance with the International Electrotechnical Commissions' (IEC) standard, Wind Turbine Generator System Part 2: Design requirements for small wind turbines, IEC 61400-2 Ed.2.0, 2006-03.
Wind Turbine Generator System Safety and Function Test Report for the Ventera VT10 Wind Turbine
This report summarizes the results of a safety and function test that NREL conducted on the Ventera VT10 wind turbine. This test was conducted in accordance with the International Electrotechnical Commissions' (IEC) standard, Wind Turbine Generator System Part 2: Design requirements for small wind turbines, IEC 61400-2 Ed.2.0, 2006-03.
Understanding Trends in Wind Turbine Prices Over the Past Decade
Taking a bottom-up approach, this report examines seven primary drivers of wind turbine prices in the United States, with the goal of estimating the degree to which each contributed to the doubling in turbine prices from 2002 through 2008, as well as the subsequent decline in prices through 2010 (our analysis does not extend into 2011 because several of these drivers are best gauged on a full-year basis due to seasonality issues). The first four of these drivers can be considered, at least to some degree, endogenous influences � i.e., those that are largely within the control of the wind industry � and include changes in: 1) Labor costs, which have historically risen during times of tight turbine supply; 2) Warranty provisions, which reflect technology performance and reliability, and are most often capitalized in turbine prices; 3) Turbine manufacturer profitability, which can impact turbine prices independently of costs; and 4) Turbine design, which for the purpose of this analysis is principally manifested through increased turbine size. The other three drivers analyzed in this study can be considered exogenous influences, in that they can impact wind turbine costs but fall mostly outside of the direct control of the wind industry. These exogenous drivers include changes in: 5) Raw materials prices, which affect the cost of inputs to the manufacturing process; 6) Energy prices, which impact the cost of manufacturing and transporting turbines; and 7) Foreign exchange rates, which can impact the dollar amount paid for turbines and components imported into the United States.
Bolinger, Mark; Wiser, Ryan
Riso-M-2546 g Wind Turbine Test
Riso-M-2546 g Wind Turbine Test Wind Matic WM 17S Troels Friis Pedersen The Test Station TEST WIND MATIC WM 17S Troels Friis Pedersen The Test Station for Windmills, Ris0 Abstract* The report; DYNAMIC LOADS; HORIZONTAL AXIS TUR- BINES; MECHANICAL TESTS; NOISE; PERFORMANCE TESTING; POWER GENERATION
NREL: Wind Research - SWIFT Wind Turbine Testing and Results
SWIFT Wind Turbine Testing and Results SWIFT Wind Turbine Testing and Results The SWIFT wind turbine. Text Version As part of the National Renewable Energy Laboratory and U.S. Department of Energy (NREL/DOE) Independent Testing project, NREL is testing the SWIFT small wind turbine at the National Wind Technology Center (NWTC). The competitive grant was awarded to Cascade Engineering. The SWIFT is a 1-kilowatt (kW), five-bladed with outer ring, horizontal-axis upwind small wind turbine. The turbine's rotor diameter is 2 meters, and its hub height is 13.72 meters. The SWIFT uses a single-phase permanent-magnet generator rated at 1 kW grid connected through an inverter at 240 volts AC. Testing Summary Supporting data and explanations for data provided in this table will be provided in the final reports. Data presented are preliminary and subject
Utility Scale Wind Turbine,� with a preliminary author lista Utility Scale Wind Turbine� with a preliminary author listUtility Scale Wind Turbine Including Operational E?ects� with a preliminary author list
Dynamic analysis of a 5 megawatt offshore floating wind turbine
1985. 23. Hau, E. Wind Turbines: Fundamentals, Technologies,for Floating Offshore Wind Turbines. Tech. no. NREL/CP-500-Full-scale Floating Wind Turbine." Statoil, 14 Oct. 2009.
Harriger, Evan Michael
Bloomberg NEF�). 2011c. Wind Turbine Price Index, Issue V.Hand, A. Laxson. 2006. Wind Turbine Design Cost and Scalingof a Multi-MegaWatt Wind Turbine. � Renewable Energy, vol.
Bolinger, Mark
How Does a Wind Turbine Work?
Wind turbines operate on a simple principle. The energy in the wind turns two or three propeller-like blades around a rotor. The rotor is connected to the main shaft, which spins a generator to...
Siting technologies for large wind turbine clusters
Site selection for large wind turbine clusters requires thorough documentation of the wind characteristics at the site, because of the influence these characteristics will have on the economics, operations, and service life of the wind turbines. The wind prospecting strategy can be used by a utility to determine specific locations for each wind turbine in a cluster of 10 to 50 or more machines. The key to site selection is knowing what and where to measure. Siting techniques to be used at the various stages of the wind-prospecting strategy are discussed. These techniques help determine where to measure. What to measure at a site is still a moot question. Suggestions are made on what data are needed at what sampling rates. These are based on the assumption that until further experience in siting large clusters of wind turbines is in hand, thorough documentation of wind characteristics affecting machine and cluster output characteristics, operation strategies, and service life are necessary.
Hiester, T.R.; Pennell, W.T.
The use of wind power to generate electricity continues to grow, especially given commitments by various countries throughout the world to ensure that a significant percentage of energy comes from renewable sources. In order to meet such objectives, increasingly larger turbines with higher capacity are being developed. The engineering aspects of larger turbine development tend to focus on design and materials for blades and towers. However, foundations are also a critical component of large wind turbines and represent a significant cost of wind energy projects. Ongoing wind research at BNL is examining two areas: (a) structural response analysis of wind turbine-tower-foundation systems and (b) materials engineering of foundations. This work is investigating the dynamic interactions in wind turbine systems, which in turn assists the wind industry in achieving improved reliability and more cost efficient foundation designs. The results reported herein cover initial studies of concrete mix designs for large wind turbine foundations and how these may be tailored to reduce cost and incorporate sustainability and life cycle concepts. The approach taken was to investigate material substitutions so that the environmental, energy and CO{sub 2}-impact of concrete could be reduced. The use of high volumes of ''waste'' materials in concrete was examined. These materials included fly ash, blast furnace slag and recycled concrete aggregate. In addition, the use of steel fiber reinforcement as a means to improve mechanical properties and potentially reduce the amount of bar reinforcement in concrete foundations was studied. Four basic mixes were considered. These were: (1) conventional mix with no material substitutions, (2) 50% replacement of cement with fly ash, (3) 50% replacement of cement with blast furnace slag and (4) 25% replacement of cement with fly ash and 25% replacement with blast furnace slag. Variations on these mixes included the addition of 1% by volume steel fibers. The use of recycled concrete aggregate in the conventional and 50% slag mixes was also studied. Properties investigated included compressive and tensile strengths, elastic modulus, coefficient of permeability, thermal conductivity and durability in seawater and sulfate solutions. It was determined that the mixes containing 50% slag gave the best overall performance. Slag was particularly beneficial for concrete that used recycled aggregate and could reduce strength losses. Initial durability results indicated that corrosion of fibers in the different concrete mixes when exposed to seawater was minimal. Future research needs to include more detailed studies of mix design and properties of concrete for wind turbine foundations. Emphasis on slag-modified mixes with natural and recycled concrete aggregate is recommended. The proportion of slag that can be incorporated in the concrete needs to be optimized, as does the grading of recycled aggregate. The potential for using silica fume in conjunction with slag is worth exploring as this may further enhance strength and durability. Longer-term durability studies are necessary and other pertinent properties of concrete that require investigation include damping characteristics, pullout strength, fatigue strength and risk of thermal cracking. The properties of sustainable concrete mixes need to be integrated with studies on the structural behavior of wind turbine foundations in order to determine the optimal mix design and to examine means of reducing conservatism and cost of foundations.
Wind energy is considered as the most viable renewable energy options. In a renewable energy system more energy from the wind. One of the options is to use the variable speed wind turbine-speed wind turbine system for transient studies are discussed in this paper. The performance of wind energy
Though wind turbines and windmills have been used for centuries, the application of aerodynamics technology to improve reliability and reduce costs of wind-generated energy has only been pursued in earnest for the past 40 years. Today, wind energy is mainly used to generate electricity. Wind is a renewable energy source. Power production from wind turbines is affected by certain conditions: wind speed, turbine speed, turbulence and the changes of wind direction. These conditions are not always optimal and have negative effects on most turbines. The present turbine is supposed to be less affected by these conditions because the blades combine a rotating movement around each own axis and around the nacelle�s one. Due to this combination of movements, flow around this turbine can be more highly unsteady, because of great blade stagger angles. The turbine has a rotor with three straight blades of symmetrical airfoil. Paper presents unsteady simulations that have been performed for one wind velocity, and different initial blades stagger angles. The influence of interaction of blades is studied for one specific constant rotational speed among the four rotational speeds that have been studied.
A. C. Bayeul-lain�; G. Bois
2.2.1 Turbine Description . . . . . . . . . . . . . . . . .112 4.2 Description of Turbine . . . . . . . . . . . . . . .3.2.1 Description of Test Wind Turbine . . . . . .
Experimental Study of Stability Limits for Slender Wind Turbine Blades.
??There is a growing interest in extracting more power per turbine by increasing the rotor size in offshore wind turbines. As a result, the turbine� (more)
Ladge, Shruti
CgWind: A high-order accurate simulation tool for wind turbines and wind farms
CgWind is a high-fidelity large eddy simulation (LES) tool designed to meet the modeling needs of wind turbine and wind park engineers. This tool combines several advanced computational technologies in order to model accurately the complex and dynamic nature of wind energy applications. The composite grid approach provides high-quality structured grids for the efficient implementation of high-order accurate discretizations of the incompressible Navier-Stokes equations. Composite grids also provide a natural mechanism for modeling bodies in relative motion and complex geometry. Advanced algorithms such as matrix-free multigrid, compact discretizations and approximate factorization will allow CgWind to perform highly resolved calculations efficiently on a wide class of computing resources. Also in development are nonlinear LES subgrid-scale models required to simulate the many interacting scales present in large wind turbine applications. This paper outlines our approach, the current status of CgWind and future development plans.
Chand, K K; Henshaw, W D; Lundquist, K A; Singer, M A
Mixer-Ejector Wind Turbine: Breakthrough High Efficiency Shrouded Wind Turbine
Broad Funding Opportunity Announcement Project: FloDesign Wind Turbine�s innovative wind turbine, inspired by the design of jet engines, could deliver 300% more power than existing wind turbines of the same rotor diameter by extracting more energy over a larger area. FloDesign Wind Turbine�s unique shrouded design expands the wind capture area, and the mixing vortex downstream allows more energy to flow through the rotor without stalling the turbine. The unique rotor and shrouded design also provide significant opportunity for mass production and simplified assembly, enabling mid-scale turbines (approximately 100 kW) to produce power at a cost that is comparable to larger-scale conventional turbines.
UMore Park Wind Turbine Project Loggerhead Shrike Survey, DOE...
UMore Park Wind Turbine Project Loggerhead Shrike Survey, DOEEA-1791 (June 2010) UMore Park Wind Turbine Project Loggerhead Shrike Survey, DOEEA-1791 (June 2010) The project area...
EA-1923: Green Energy School Wind Turbine Project on Saipan,...
3: Green Energy School Wind Turbine Project on Saipan, Commonwealth of the Northern Mariana Islands EA-1923: Green Energy School Wind Turbine Project on Saipan, Commonwealth of the...
Lattice Tower Design of Offshore Wind Turbine Support Structures.
??Optimal design of support structure including foundation and turbine tower is among the most critical challenges for offshore wind turbine. With development of offshore wind� (more)
Gong, W.
Use of SCADA Data for Failure Detection in Wind Turbines
This paper discusses the use of existing wind turbine SCADA data for development of fault detection and diagnostic techniques for wind turbines.
Kim, K.; Parthasarathy, G.; Uluyol, O.; Foslien, W.; Sheng, S.; Fleming, P.
Wind Turbine Generator Condition Monitoring via the Generator Control Loop.
??This thesis focuses on the development of condition monitoring techniques for application in wind turbines, particularly for offshore wind turbine driven doubly fed induction generators.� (more)
Manufacturing Defects Common to Composite Wind Turbine Blades: Effects of Defects
1 Manufacturing Defects Common to Composite Wind Turbine Blades: Effects of Defects Jared W. Nelson The Blade Reliability Collaborative has been formed to perform comprehensive studies to improve wind turbine uni-directional wind turbine fiber-reinforced composite material with an epoxy resin were utilized
EA-1792: University of Maine's Deepwater Offshore Floating Wind Turbine
EA-1792: University of Maine's Deepwater Offshore Floating Wind EA-1792: University of Maine's Deepwater Offshore Floating Wind Turbine Testing and Demonstration Project, Gulf of Maine EA-1792: University of Maine's Deepwater Offshore Floating Wind Turbine Testing and Demonstration Project, Gulf of Maine Summary This EA evaluates the environmental impacts of a proposal to support research on floating offshore wind turbine platforms. This project would support the mission, vision, and goals of DOE's Office of Energy Efficiency and Renewable Energy Wind and Water Power Program to improve performance, lower costs, and accelerate deployment of innovative wind power technologies. Development of offshore wind energy technologies would help the nation reduce its greenhouse gas emissions, diversify its energy supply, provide cost-competitive electricity to key coastal regions, and
Luther College Wind Turbine | Open Energy Information
Luther College Wind Turbine Luther College Wind Turbine Jump to: navigation, search Name Luther College Wind Turbine Facility Luther College Wind Turbine Sector Wind energy Facility Type Community Wind Facility Status In Service Owner Luther College Wind Energy Project LLC Developer Luther College Energy Purchaser Alliant Energy Location Decorah IA Coordinates 43.30919891°, -91.81617737° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":43.30919891,"lon":-91.81617737,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
NREL: Wind Research - Abundant Renewable Energy's ARE 442 Wind Turbine
Abundant Renewable Energy's ARE 442 Wind Turbine Testing and Results Abundant Renewable Energy's ARE 442 Wind Turbine Testing and Results Get the Adobe Flash Player to see this video. A video of Abundant Renewable Energy's ARE 442 wind turbine. Text Version As part of the National Renewable Energy Laboratory and U.S. Department of Energy (NREL/DOE) Independent Testing project, NREL tested Abundant Renewable Energy's ARE 442 turbine at the National Wind Technology Center (NWTC). The ARE 442 is a 10-kilowatt (kW), three-bladed, horizontal-axis upwind small wind turbine. It has a hub height of 30.9 meters and a rotor diameter of 7.2 meters. The turbine has a single-phase permanent-magnet generator that operates at variable voltages up to 410 volts AC. Testing Summary The summary of the tests is below with the final reports.
Fatigue case study and reliability analyses for wind turbines
Modern wind turbines are fatigue critical machines used to produce electrical power. To insure long term, reliable operation, their structure must be optimized if they are to be economically viable. The fatigue and reliability projects in Sandia`s Wind Energy Program are developing the analysis tools required to accomplish these design requirements. The first section of the paper formulates the fatigue analysis of a wind turbine using a cumulative damage technique. The second section uses reliability analysis for quantifying the uncertainties and the inherent randomness associated with turbine performance and the prediction of service lifetimes. Both research areas are highlighted with typical results.
Sutherland, H.J.; Veers, P.S.
An overview of DOE`s wind turbine development programs
The development of technologically advanced, higher efficiency wind turbines continues to be a high priority activity of the US wind industry. The United States Department of Energy (DOE) is conducting and sponsoring a range of programs aimed at assisting the wind industry with system design, development, and testing. The overall goal is to develop systems that can compete with conventional electric generation for $.05/kWh at 5.8 m/s (13 mph sites) by the mid-1990s and with fossil-fuel-based generators for $.04/kWh at 5.8 m/s sites by the year 2000. These goals will be achieved through several programs. The Value Engineered Turbine Program will promote the rapid development of US capability to manufacture wind turbines with known and well documented records of performance, cost, and reliability, to take advantage of near-term market opportunities. The Advanced Wind Turbine Program will assist US industry to develop and integrate innovative technologies into utility-grade wind turbines for the near-term (mid 1990s) and to develop a new generation of turbines for the year 2000. The collaborative Electric Power Research Institute (EPRI)/DOE Utility Wind Turbine Performance Verification Program will deploy and evaluate commercial-prototype wind turbines in typical utility operating environments, to provide a bridge between development programs currently underway and commercial purchases of utility-grade wind turbines. A number of collaborative efforts also will help develop a range of small systems optimized to work in a diesel hybrid environment to provide electricity for smaller non-grid-connected applications.
Laxson, A; Dodge, D; Flowers, L [National Renewable Energy Lab., Golden, CO (United States); Loose, R; Goldman, P [Dept. of Energy, Washington, DC (United States)
Responses of floating wind turbines to wind and wave excitation
The use of wind power has recently emerged as a promising alternative to conventional electricity generation. However, space requirements and public pressure to place unsightly wind turbines out of visual range make it ...
Lee, Kwang Hyun
Lightning protection system for a wind turbine
In a wind turbine (104, 500, 704) having a plurality of blades (132, 404, 516, 744) and a blade rotor hub (120, 712), a lightning protection system (100, 504, 700) for conducting lightning strikes to any one of the blades and the region surrounding the blade hub along a path around the blade hub and critical components of the wind turbine, such as the generator (112, 716), gearbox (708) and main turbine bearings (176, 724).
Costin, Daniel P. (Chelsea, VT); Petter, Jeffrey K. (Williston, VT)
Certification testing for small wind turbines
This paper describes the testing procedures for obtaining type certification for a small wind turbine. Southwest Windpower (SWWP) is seeking type certification from Underwriters Laboratory (UL) for the AIR 403 wind turbine. UL is the certification body and the National Renewable Energy Laboratory (NREL) is providing technical assistance including conducting the certification testing. This is the first small turbine to be certified in the US, therefore standards must be interpreted and test procedures developed.
Corbus, D.; Link, H.; Butterfield, S.; Stork, C.; Newcomb, C.
Power control of a wind farm with active stall wind turbines and AC grid connection
turbines with AC connection. The control of other wind farm concepts such as wind farms with DFIG wind
Real-time wind turbine emulator suitable for power quality and dynamic control studies, MASc Thesis
Abstract � Wind turbines are increasingly becoming significant components of power systems. To evaluate competing wind energy conversion technologies, a real-time Wind Turbine Emulator, which emulates the dynamic torque produced by an actual turbine has been developed. This is necessary since the real world performance of a wind turbine, subjected to variable wind conditions is more difficult to evaluate than a standard turbine generator system operating in near steady state. This emulator is capable of reproducing both the static and dynamic torque of an actual wind turbine. It models the torque oscillations caused by wind shear, tower shadow, and the obvious pulsations caused by variable wind speed. Also included are the dynamic effects of a large turbine inertia. This emulator will allow testing without the costly construction of the actual turbine blades and tower to determine the strengths and weaknesses of competing energy conversion and control technologies.
Dale S. L. Dolan; Student Member; P. W. Lehn; Member Ieee
Wind Turbine Blade Structural Health Monitoring
Structural health monitoring (SHM) is the automated inspection and evaluation of structures such as wind turbine blades. This report examines the current state-of-the-art blade SHM systems, identifies future trends, and outlines a methodology for probabilistic cost-benefit analysis of the application of SHM systems to wind turbine blades. The reliability of wind turbine blades is an ongoing concern for the wind industry. Applying SHM to blades may be one way to reduce blade failure rates and reduce the d...
Wind Turbine Towers Establish New Height Standards and Reduce...
Wind Turbine Towers Establish New Height Standards and Reduce Cost of Wind Energy Wind Turbine Towers Establish New Height Standards and Reduce Cost of Wind Energy Case study that...
Williams Stone Wind Turbine | Open Energy Information
Wind Turbine Wind Turbine Jump to: navigation, search Name Williams Stone Wind Turbine Facility Williams Stone Wind Turbine Sector Wind energy Facility Type Community Wind Facility Status In Service Owner Williams Stone Developer Sustainable Energy Developments Energy Purchaser Williams Stone Location Otis MA Coordinates 42.232526°, -73.070952° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.232526,"lon":-73.070952,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Charlestown Wind Turbine | Open Energy Information
Charlestown Wind Turbine Charlestown Wind Turbine Jump to: navigation, search Name Charlestown Wind Turbine Facility Charlestown Wind Turbine Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner MWRA Developer MWRA Energy Purchaser Distributed generation - net metered Location Boston MA Coordinates 42.39094522°, -71.07094288° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.39094522,"lon":-71.07094288,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Nature's Classroom Wind Turbine | Open Energy Information
Nature's Classroom Wind Turbine Nature's Classroom Wind Turbine Jump to: navigation, search Name Nature's Classroom Wind Turbine Facility Nature's Classroom Wind Turbine Sector Wind energy Facility Type Small Scale Wind Facility Status In Service Owner Nature's Classroom Energy Purchaser Nature's Classroom Location Charlton MA Coordinates 42.113685°, -72.008475° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.113685,"lon":-72.008475,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Meteorological aspects of siting large wind turbines
This report, which focuses on the meteorological aspects of siting large wind turbines (turbines with a rated output exceeding 100 kW), has four main goals. The first is to outline the elements of a siting strategy that will identify the most favorable wind energy sites in a region and that will provide sufficient wind data to make responsible economic evaluations of the site wind resource possible. The second is to critique and summarize siting techniques that were studied in the Department of Energy (DOE) Wind Energy Program. The third goal is to educate utility technical personnel, engineering consultants, and meteorological consultants (who may have not yet undertaken wind energy consulting) on meteorological phenomena relevant to wind turbine siting in order to enhance dialogues between these groups. The fourth goal is to minimize the chances of failure of early siting programs due to insufficient understanding of wind behavior.
Influence of refraction on wind turbine noise
A semi-empirical method is applied to calculate the time-average sound level of wind turbine noise generation and propagation. Both are affected by wind shear refraction. Under upwind conditions the partially ensonified zone separates the fully ensonified zone (close to the turbine) and the shadow zone (far away from the turbine). Refraction is described in terms of the wind speed linear profile fitted to the power law profile. The rotating blades are treated as a two-dimensional circular source in the vertical plane. Inside the partially ensonified zone the effective A-weighted sound power decreases to zero when the receiver moves from the turbine toward the shadow zone. The presented results would be useful in practical applications to give a quick estimate of the effect of refraction on wind turbine noise.
Makarewicz, Rufin
Wind Turbine Lubrication Maintenance Guide
With the rush to develop todays massive wind energy sites, more attention should be paid to the inevitable need to perform routine maintenance and develop practical means of assessing the condition of the components within the nacelles and other outside support equipment for the wind farms. Current operating models have not adequately established accurate assumptions or expectations on the unavailability of the windmills and the impact on lost generation. Contracts for purchase of their generation output...
Minimization of Motion Smear: Reducing Avian Collision with Wind Turbines; Period of Performance: July 12, 1999 -- August 31, 2002
Collisions with wind turbines can be a problem for many species of birds. Of particular concern are collisions by eagles and other protected species. This research study used the laboratory methods of physiological optics, animal psychophysics, and retinal electrophysiology to analyze the causes of collisions and to evaluate visual deterrents based on the results of this analysis. Bird collisions with the seemingly slow-moving turbines seem paradoxical given the superb vision that most birds, especially raptors, possess. However, our optical analysis indicated that as the eye approaches the rotating blades, the retinal image of the blade (which is the information that is transmitted to the animal's brain) increases in velocity until it is moving so fast that the retina cannot keep up with it. At this point, the retinal image becomes a transparent blur that the bird probably interprets as a safe area to fly through, with disastrous consequences. This phenomenon is called"motion smear" or"motion blur."
Hodos, W.
of Turbine Rotor . . . . . . . . . . . . . . 3.9 Results ofA. C. (2006). �WindPACT turbine rotor design study. � ReportA. C. (2006). �WindPACT turbine rotor design study. � Report
Automatic Detection of Wind Turbine Clutter for Weather Radars
Wind turbines cause contamination of weather radar signals that is often detrimental and difficult to distinguish from cloud returns. Because the turbines are always at the same location, it would seem simple to identify where wind turbine ...
Kenta Hood; Sebasti�n Torres; Robert Palmer
Advanced Wind Turbine Controls Reduce Loads (Fact Sheet)
NREL's National Wind Technology Center provides the world's only dedicated turbine controls testing platforms.
Loads Analysis of Several Offshore Floating Wind Turbine Concepts
This paper presents a comprehensive dynamic-response analysis of six offshore floating wind turbine concepts.
Robertson, A. N.; Jonkman, J. M.
Wind Turbine Productivity and Development in Iran
This paper presents an overview of the status of wind energy productivity and development issues in Iran. It also presents a summary of the present global work on offshore energy, including the most recent works as well as potential offshore wind energy ... Keywords: Iran, development, offshore, turbine, wind
Ali Mostafaeipour; Saeid Abesi
PowerJet Wind Turbine Project
PROJECT OBJECTIVE The PowerJet wind turbine overcomes problems characteristic of the small wind turbines that are on the market today by providing reliable output at a wide range of wind speeds, durability, silent operation at all wind speeds, and bird-safe operation. Prime Energy��?s objective for this project was to design and integrate a generator with an electrical controller and mechanical controls to maximize the generation of electricity by its wind turbine. The scope of this project was to design, construct and test a mechanical back plate to control rotational speed in high winds, and an electronic controller to maximize power output and to assist the base plate in controlling rotational speed in high winds. The test model will continue to operate beyond the time frame of the project, with the ultimate goal of manufacturing and marketing the PowerJet worldwide. Increased Understanding of Electronic & Mechanical Controls Integrated With Electricity Generator The PowerJet back plate begins to open as wind speed exceeds 13.5 mps. The pressure inside the turbine and the turbine rotational speed are held constant. Once the back plate has fully opened at approximately 29 mps, the controller begins pulsing back to the generator to limit the rotational speed of the turbine. At a wind speed in excess of 29 mps, the controller shorts the generator and brings the turbine to a complete stop. As the wind speed subsides, the controller releases the turbine and it resumes producing electricity. Data collection and instrumentation problems prevented identification of the exact speeds at which these events occur. However, the turbine, controller and generator survived winds in excess of 36 mps, confirming that the two over-speed controls accomplished their purpose. Technical Effectiveness & Economic Feasibility Maximum Electrical Output The output of electricity is maximized by the integration of an electronic controller and mechanical over-speed controls designed and tested during the course of this project. The output exceeds that of the PowerJet��?s 3-bladed counterparts (see Appendix). Durability All components of the PowerJet turbine assembly��?including the electronic and mechanical controls designed, manufactured and field tested during the course of this project��?proved to be durable through severe weather conditions, with constant operation and no interruption in energy production. Low Cost Materials for the turbine, generator, tower, charge controllers and ancillary parts are available at reasonable prices. Fabrication of these parts is also readily available worldwide. The cost of assembling and installing the turbine is reduced because it has fewer parts and requires less labor to manufacture and assemble, making it competitively priced compared with turbines of similar output manufactured in the U.S. and Europe. The electronic controller is the unique part to be included in the turbine package. The controllers can be manufactured in reasonably-sized production runs to keep the cost below $250 each. The data logger and 24 sensors are for research only and will be unnecessary for the commercial product. Benefit To Public The PowerJet wind-electric system is designed for distributed wind generation in 3 and 4 class winds. This wind turbine meets DOE��?s requirements for a quiet, durable, bird-safe turbine that eventually can be deployed as a grid-connected generator in urban and suburban settings. Results As described more fully below and illustrated in the Appendices, the goals and objectives outlined in 2060 SOPO were fully met. Electronic and mechanical controls were successfully designed, manufactured and integrated with the generator. The turbine, tower, controllers and generators operated without incident throughout the test period, surviving severe winter and summer weather conditions such as extreme temperatures, ice and sustained high winds. The electronic controls were contained in weather-proof electrical boxes and the elec
Bartlett, Raymond J
NREL: Wind Research - Gaia-Wind's 11 Kilowatt Wind Turbine Testing and
Gaia-Wind's 11 Kilowatt Wind Turbine Testing and Results Gaia-Wind's 11 Kilowatt Wind Turbine Testing and Results A video of Gaia-Wind's 11-kW wind turbine. Text Version As part of the National Renewable Energy Laboratory and U.S. Department of Energy (NREL/DOE) Independent Testing project, NREL tested Gaia-Wind's 11-kilowatt (kW) small wind turbine at the National Wind Technology Center (NWTC). Gaia-Wind's turbine is a three-phase induction generator that operates at 480 volts. The turbine's downwind rotor has a 13-meter diameter, and its tower is 18 meters tall. The two-bladed, oversized rotor is designed for low to moderate wind speeds. Testing Summary The summary of the tests is below with the final reports. Cumulative Energy Production 6/11/2008: 210; 6/13/2008: 528; 6/16/2008: 716; 6/18/2008: 731; 6/19/2008:
Coupled Dynamic Modeling of Floating Wind Turbine Systems: Preprint
This article presents a collaborative research program that the Massachusetts Institute of Technology (MIT) and the National Renewable Energy Laboratory (NREL) have undertaken to develop innovative and cost-effective floating and mooring systems for offshore wind turbines in water depths of 10-200 m. Methods for the coupled structural, hydrodynamic, and aerodynamic analysis of floating wind turbine systems are presented in the frequency domain. This analysis was conducted by coupling the aerodynamics and structural dynamics code FAST [4] developed at NREL with the wave load and response simulation code WAMIT (Wave Analysis at MIT) [15] developed at MIT. Analysis tools were developed to consider coupled interactions between the wind turbine and the floating system. These include the gyroscopic loads of the wind turbine rotor on the tower and floater, the aerodynamic damping introduced by the wind turbine rotor, the hydrodynamic damping introduced by wave-body interactions, and the hydrodynamic forces caused by wave excitation. Analyses were conducted for two floater concepts coupled with the NREL 5-MW Offshore Baseline wind turbine in water depths of 10-200 m: the MIT/NREL Shallow Drafted Barge (SDB) and the MIT/NREL Tension Leg Platform (TLP). These concepts were chosen to represent two different methods of achieving stability to identify differences in performance and cost of the different stability methods. The static and dynamic analyses of these structures evaluate the systems' responses to wave excitation at a range of frequencies, the systems' natural frequencies, and the standard deviations of the systems' motions in each degree of freedom in various wind and wave environments. This article in various wind and wave environments. This article explores the effects of coupling the wind turbine with the floating platform, the effects of water depth, and the effects of wind speed on the systems' performance. An economic feasibility analysis of the two concepts was also performed. Key cost components included the material and construction costs of the buoy; material and installation costs of the tethers, mooring lines, and anchor technologies; costs of transporting and installing the system at the chosen site; and the cost of mounting the wind turbine to the platform. The two systems were evaluated based on their static and dynamic performance and the total system installed cost. Both systems demonstrated acceptable motions, and have estimated costs of $1.4-$1.8 million, not including the cost of the wind turbine, the power electronics, or the electrical transmission.
Wayman, E. N.; Sclavounos, P. D.; Butterfield, S.; Jonkman, J.; Musial, W.
Solving Wind Turbine Tribological Issues with Materials Science
Abstract Scope, Wind energy is becoming more important to society as we are ... Large wind turbines convert the mechanical energy harnessed from the wind�...
Wind turbine having a direct-drive drivetrain - Energy Innovation ...
A wind turbine comprising an electrical generator that includes a rotor assembly. A wind rotor that includes a wind rotor hub is directly coupled to the rotor ...
Methods and apparatus for reducing peak wind turbine loads ...
A method for reducing peak loads of wind turbines in a changing wind environment includes measuring or estimating an instantaneous wind speed and direction at the ...
Enabling New Markets for Offshore Wind Energy." Proc. ofMary, and Laura Parsons. Offshore Wind Energy. Washingto,Challenges for Floating Offshore Wind Turbines. Tech. no.
Enabling New Markets for Offshore Wind Energy." Proc. ofand Laura Parsons. Offshore Wind Energy. Washingto, DC:Challenges for Floating Offshore Wind Turbines. Tech. no.
Coupled Dynamic Analysis of Multiple Unit Floating Offshore Wind Turbine
In the present study, a numerical simulation tool has been developed for the rotor-floater-tether coupled dynamic analysis of Multiple Unit Floating Offshore Wind Turbine (MUFOWT) in the time domain including aero-blade-tower dynamics and control, mooring dynamics and platform motion. In particular, the numerical tool developed in this study is based on the single turbine analysis tool FAST, which was developed by National Renewable Energy Laboratory (NREL). For linear or nonlinear hydrodynamics of floating platform and generalized-coordinate-based FEM mooring line dynamics, CHARM3D program, hull-riser-mooring coupled dynamics program developed by Prof. M.H. Kim�s research group during the past two decades, is incorporated. So, the entire dynamic behavior of floating offshore wind turbine can be obtained by coupled FAST-CHARM3D in the time domain. During the coupling procedure, FAST calculates all the dynamics and control of tower and wind turbine including the platform itself, and CHARM3D feeds all the relevant forces on the platform into FAST. Then FAST computes the whole dynamics of wind turbine using the forces from CHARM3D and return the updated displacements and velocities of the platform to CHARM3D. To analyze the dynamics of MUFOWT, the coupled FAST-CHARM3D is expanded more and re-designed. The global matrix that includes one floating platform and a number of turbines is built at each time step of the simulation, and solved to obtain the entire degrees of freedom of the system. The developed MUFOWT analysis tool is able to compute any type of floating platform with various kinds of horizontal axis wind turbines (HAWT). Individual control of each turbine is also available and the different structural properties of tower and blades can be applied. The coupled dynamic analysis for the three-turbine MUFOWT and five-turbine MUFOWT are carried out and the performances of each turbine and floating platform in normal operational condition are assessed. To investigate the coupling effect between platform and each turbine, one turbine failure event is simulated and checked. The analysis shows that some of the mal-function of one turbine in MUFOWT may induce significant changes in the performance of other turbines or floating platform. The present approach can directly be applied to the development of the remote structural health monitoring system of MUFOWT in detecting partial turbine failure by measuring tower or platform responses in the future.
Bae, Yoon Hyeok
Dual-speed wind turbine generation
Induction generator has been used since the early development of utility-scale wind turbine generation. An induction generator is the generator of choice because of its ruggedness and low cost. With an induction generator, the operating speed of the wind turbine is limited to a narrow range (almost constant speed). Dual- speed operation can be accomplished by using an induction generator with two different sets of winding configurations or by using a dual output drive train to drive two induction generators with two different rated speeds. With single-speed operation, the wind turbine operates at different power coefficients (Cp) as the wind speed varies. Operation at maximum Cp can occur only at a single wind speed. However, if the wind speed.varies across a wider range, the operating Cp will vary significantly. Dual-speed operation has the advantage of enabling the wind turbine to operate at near maximum Cp over a wider range of wind speeds. Thus, annual energy production can be increased. The dual-speed mode may generate less energy than a variable-speed mode; nevertheless, it offers an alternative which captures more energy than single-speed operation. In this paper, dual-speed operation of a wind turbine is investigated. Annual energy production is compared between single-speed and dual-speed operation. One type of control algorithm for dual-speed operation is proposed. Some results from a dynamic simulation will be presented to show how the control algorithm works as the wind turbine is exposed to varying wind speeds.
Muljadi, E.; Butterfield, C.P. [National Renewable Energy Lab., Golden, CO (United States); Handman, D. [Flowind Corp., San Rafael, CA (United States)
Steam Turbine Performance Engineer's Guide
The Steam Turbine Performance Engineer's Guide is meant to present the steam turbine performance engineer with the expected and important functions and responsibilities necessary to succeed in this position that are not necessarily taught in college. The instructions and recommendations in this guide, when properly executed, will improve the effectiveness of steam turbine performance engineers, positively affecting both the performance and reliability of the steam turbines under their care.
k-? turbulence modeling for a wind turbine.
?? In this report we discuss the use of k-? RANS (Reynolds-averaged Navier-Stokes equations) turbulence model for wind turbine applications. This model has been implemented� (more)
Airfoils for wind turbine - Energy Innovation Portal
Airfoils for the tip and mid-span regions of a wind turbine blade have upper surface and lower surface shapes and contours between a leading edge and a trailing edge ...
Diffuser for augmenting a wind turbine
A diffuser for augmenting a wind turbine having means for energizing the boundary layer at several locations along the diffuser walls is improved by the addition of a short collar extending radially outward from the outlet of the diffuser.
Foreman, Kenneth M. (North Bellmore, NY); Gilbert, Barry L. (Westbury, NY)
Direct drive wind turbine - Energy Innovation Portal
A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The ...
Flexible dynamics of floating wind turbines
This work presents Tower Flex, a structural dynamics model for a coupled analysis of offshore floating wind turbines consisting of a tower, a floating platform and a mooring system. In this multi-body, linear frequency-domain ...
Luypaert, Thomas (Thomas J.)
Wind Turbine Drivetrain Condition Monitoring - An Overview
This paper provides an overview of wind turbine drivetrain condition monitoring based on presentations from a condition monitoring workshop organized by the National Renewable Energy Laboratory in 2009 and on additional references.
Sheng, S; Veers, P.
Vertical Axis Wind Turbine Foundation parameter study
The dynamic failure criterion governing the dimensions of prototype Vertical Axis Wind Turbine Foundations is treated as a variable parameter. The resulting change in foundation dimensions and costs is examined.
Lodde, P.F.
Experimental and analytical research on the aerodynamics of wind turbines. Mid-term technical report, June 1--December 31, 1975
The successful development of reliable, cost competitive horizontal axis, propeller-type wind energy conversion systems (WECS) is strongly dependent on the availability of advanced technology for each of the system components. Past experience and current studies of this type of wind energy conversion systems have shown that the wind turbine subsystem most significantly effects the system's cost effectiveness and performance capability. Thus adequate technology bases are essential for all elements of the wind turbine design. Information is presented concerning aerodynamic design and performance technology, wind turbine parametric performance study, selection of model wind turbine configurations, and structural design of wind turbine models.
Rohrbach, C.
Nonlinear Control of a Wind Turbine Sven Creutz Thomsen
. This quantity is denoted the point wind. However, the turbine is not subject to a single wind speed, but ratherNonlinear Control of a Wind Turbine Sven Creutz Thomsen Kongens Lyngby 2006 #12;Technical describes analysis of various nonlinear control methods for controlling a wind turbine. High speed wind
A Study on Vibration Isolation in a Wind Turbine Subjected to Wind and Seismic Loading.
??The primary loading on wind turbines is in the lateral direction and is of a stochastic nature, due to wind and seismic forces. As turbines� (more)
Van der Woude, Chad
Passively cooled direct drive wind turbine
A wind turbine is provided that passively cools an electrical generator. The wind turbine includes a plurality of fins arranged peripherally around a generator house. Each of the fins being oriented at an angle greater than zero degrees to allow parallel flow of air over the fin. The fin is further tapered to allow a constant portion of the fin to extend beyond the air stream boundary layer. Turbulence initiators on the nose cone further enhance heat transfer at the fins.
Costin, Daniel P. (Chelsea, VT)
Development of a Scale Model Wind Turbine for Testing of Offshore Floating Wind Turbine Systems.
??This thesis presents the development of a 1/50th scale 5 MW wind turbine intended for wind and wave basin model testing of commercially viable floating� (more)
Martin, Heather Rae
NREL Small Wind Turbine Test Project: Mariah Power's Windspire Wind Turbine Test Chronology
This report presents a chronology of tests conducted at NREL's National Wind Technology Center on Mariah Power's Windspire 1.2-kW wind turbine and a letter of response from Mariah Power.
Huskey, A.; Forsyth, T.
Applied Materials Wind Turbine | Open Energy Information
Wind Turbine Wind Turbine Jump to: navigation, search Name Applied Materials Wind Turbine Facility Applied Materials Sector Wind energy Facility Type Community Wind Facility Status In Service Owner Applied Materials Developer Applied Materials Energy Purchaser Applied Materials Location Gloucester MA Coordinates 42.62895426°, -70.65153122° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.62895426,"lon":-70.65153122,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Portsmouth Wind Turbine | Open Energy Information
Portsmouth Wind Turbine Portsmouth Wind Turbine Facility Portsmouth Wind Turbine Sector Wind energy Facility Type Community Wind Facility Status In Service Owner Town of Portsmouth Energy Purchaser Town of Portsmouth Location Portsmouth RI Coordinates 41.614216°, -71.25165° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":41.614216,"lon":-71.25165,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Economic Impacts of Wind Turbine Development in U.S. Counties
15 percent)). Cumulative wind turbine capacity installed inper capita income of wind turbine development (measured inour sample, cumulative wind turbine capacity on a per person
J., Brown
Wind Power Technology Status and Performance and Cost Estimates - 2008
This report addresses the status of wind turbine and related technology for both onshore and offshore applications, and the performance and cost of onshore wind power plants. It also presents a sample analysis of wind project financial performance.
Battery Voltage Stability Effects on Small Wind Turbine Energy Capture: Preprint
Previous papers on small wind turbines have shown that the ratio of battery capacity to wind capacity (known as battery-wind capacity ratio) for small wind systems with battery storage has an important effect on wind turbine energy output. Data analysis from pilot project performance monitoring has revealed shortcomings in wind turbine energy output up to 75% of expected due to the effect of a''weak'' battery grid. This paper presents an analysis of empirical test results of small wind battery systems, showing the relationships among wind turbine charging rate, battery capacity, battery internal resistance, and the change in battery voltage. By understanding these relationships, small wind systems can be designed so as to minimize''dumped'' or unused energy from small wind turbines.
Corbus, D.; Newcomb, C.; Baring-Gould, E. I.; Friedly, S.
Jet spoiler arrangement for wind turbine
An air jet spoiler arrangement is provided for a Darrieus-type vertical axis wind-powered turbine. Air is drawn into hollow turbine blades through air inlets at the ends thereof and is ejected in the form of air jets through small holes or openings provided along the lengths of the blades. The air jets create flow separation at the surfaces of the turbine blades, thereby inducing stall conditions and reducing the output power. A feedback control unit senses the power output of the turbine and controls the amount of air drawn into the air inlets accordingly.
Cyrus, Jack D. (Corrales, NM); Kadlec, Emil G. (Albuquerque, NM); Klimas, Paul C. (Albuquerque, NM)
An air jet spoiler arrangement is provided for a Darrieus-type vertical axis wind-powered turbine. Air is drawn into hollow turbine blades through air inlets at the end thereof and is ejected in the form of air jets through small holes or openings provided along the lengths of the blades. The air jets create flow separation at the surfaces of the turbine blades, thereby including stall conditions and reducing the output power. A feedback control unit senses the power output of the turbine and controls the amount of air drawn into the air inlets accordingly.
Cyrus, J.D.; Kadlec, E.G.; Klimas, P.C.
Reaction Injection Molded 7.5 Meter Wind Turbine Blade
An optimized small turbine blade (7.5m radius) was designed and a partial section molded with the RIM (reaction-injection molded polymer) process for mass production. The intended market is for generic three-bladed wind turbines, 100 kilowatts or less, for grid-assist end users with rural and semi-rural sites, such as the farm/ranch market, having low to moderate IEC Class 3-4 wind regimes. This blade will have substantial performance improvements over, and be cheaper than, present-day 7.5m blades. This is made possible by the injection-molding process, which yields high repeatability, accurate geometry and weights, and low cost in production quantities. No wind turbine blade in the 7.5m or greater size has used this process. The blade design chosen uses a RIM skin bonded to a braided infused carbon fiber/epoxy spar. This approach is attractive to present users of wind turbine blades in the 5-10m sizes. These include rebladeing California wind farms, refurbishing used turbines for the Midwest farm market, and other manufacturers introducing new turbines in this size range.
David M. Wright; DOE Project Officer - Keith Bennett
NREL Develops Simulations for Wind Plant Power and Turbine Loads...
loading due to wake turbulence. The current state of knowledge concerning wind turbine wakes and how they interact with other turbines and the atmospheric boundary layer is...
Field verification program for small wind turbines
In 1999 Windward Engineering (Windward) was awarded a Cooperative Agreement under the Field Verification Program with the Department of Energy (DOE) to install two Whisper H40 wind turbines, one at the NREL National Wind Technology Center (NWTC) and one at a test site near Spanish Fork, Utah. After installation, the turbine at the NWTC was to be operated, maintained, and monitored by NREL while the turbine in Spanish Fork was to be administered by Windward. Under this award DOE and Windward defined the primary objectives of the project as follows: (1) Determine and demonstrate the reliability and energy production of a furling wind turbine at a site where furling will be a very frequent event and extreme gusts can be expected during the duration of the tests. (2) Make engineering measurements and conduct limited computer modeling of the furling behavior to improve the industry understanding of the mechanics and nature of furling. We believe the project has achieved these objectives. The turbine has operated for approximately three and a half years. We have collected detailed engineering data approximately 75 percent of that time. Some of these data were used in an ADAMS model validation that highlighted the accuracies and inaccuracies of the computer modeling for a passively furling wind turbine. We also presented three papers at the American Wind Energy Association (AWEA) Windpower conferences in 2001, 2002, and 2003. These papers addressed the following three topics: (a) general overview of the project [1], (b) furling operation during extreme wind events [2], and (c) extrapolation of extreme (design) loads [3]. We believe these papers have given new insight into the mechanics and nature of furling and have set the stage for future research. In this final report we will highlight some of the more interesting aspects of the project as well as summarize the data for the entire project. We will also present information on the installation of the turbines as well as the findings from the post-test inspection of the turbine.
Windward Engineering, LLC
Middelgrunden Wind Turbine Cooperative | Open Energy Information
Middelgrunden Wind Turbine Cooperative Middelgrunden Wind Turbine Cooperative Jump to: navigation, search Name Middelgrunden Wind Turbine Cooperative Place Copenhagen, Denmark Zip 2200 Sector Wind energy Product Copenhagen-based, partnership founded in May 1997 by the Working Group for Wind Turbines on Middelgrunden, with the aim to produce electricity through the establishment and management of wind turbines on the Middelgrunden shoal. Coordinates 55.67631°, 12.569355° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":55.67631,"lon":12.569355,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Iskra Wind Turbine Manufacturers Ltd | Open Energy Information
Iskra Wind Turbine Manufacturers Ltd Iskra Wind Turbine Manufacturers Ltd Jump to: navigation, search Name Iskra Wind Turbine Manufacturers Ltd Place Nottingham, United Kingdom Sector Wind energy Product Iskra manufactures and markets the AT5-1 home-sized wind turbine rated at 5.3 kW, suitable for low wind speeds. References Iskra Wind Turbine Manufacturers Ltd[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Iskra Wind Turbine Manufacturers Ltd is a company located in Nottingham, United Kingdom . References ↑ "Iskra Wind Turbine Manufacturers Ltd" Retrieved from "http://en.openei.org/w/index.php?title=Iskra_Wind_Turbine_Manufacturers_Ltd&oldid=347129" Categories: Clean Energy Organizations
Multi-hazard Reliability Assessment of Offshore Wind Turbines
A probabilistic framework is developed to assess the structural reliability of offshore wind turbines. Probabilistic models are developed to predict the deformation, shear force and bending moment demands on the support structure of wind turbines. The proposed probabilistic models are developed starting from a commonly accepted deterministic model and by adding correction terms and model errors to capture respectively, the inherent bias and the uncertainty in developed models. A Bayesian approach is then used to assess the model parameters incorporating the information from virtual experiment data. The database of virtual experiments is generated using detailed three-dimensional finite element analyses of a suite of typical offshore wind turbines. The finite element analyses properly account for the nonlinear soil-structure interaction. Separate probabilistic demand models are developed for three operational/load conditions including: (1) operating under day-to-day wind and wave loading; (2) operating throughout earthquake in presence of day-to-day loads; and (3) parked under extreme wind speeds and earthquake ground motions. The proposed approach gives special attention to the treatment of both aleatory and epistemic uncertainties in predicting the demands on the support structure of wind turbines. The developed demand models are then used to assess the reliability of the support structure of wind turbines based on the proposed damage states for typical wind turbines and their corresponding performance levels. A multi-hazard fragility surface of a given wind turbine support structure as well as the seismic and wind hazards at a specific site location are incorporated into a probabilistic framework to estimate the annual probability of failure of the support structure. Finally, a framework is proposed to investigate the performance of offshore wind turbines operating under day-to-day loads based on their availability for power production. To this end, probabilistic models are proposed to predict the mean and standard deviation of drift response of the tower. The results are used in a random vibration based framework to assess the fragility as the probability of exceeding certain drift thresholds given specific levels of wind speed.
Mardfekri Rastehkena, Maryam 1981-
Wind Turbine Micropitting Workshop: A Recap
Micropitting is a Hertzian fatigue phenomenon that affects many wind turbine gearboxes, and it affects the reliability of the machines. With the major growth and increasing dependency on renewable energy, mechanical reliability is an extremely important issue. The U.S. Department of Energy has made a commitment to improving wind turbine reliability and the National Renewable Energy Laboratory (NREL) has started a gearbox reliability project. Micropitting as an issue that needed attention came to light through this effort. To understand the background of work that had already been accomplished, and to consolidate some level of collective understanding of the issue by acknowledged experts, NREL hosted a wind turbine micropitting workshop, which was held at the National Wind Technology Center in Boulder, Colorado, on April 15 and 16, 2009.
Sheng, S.
Addendum to a proposal to NSF to sponsor a vertical-axis wind turbine research program
Information is presented concerning the performance evaluation of a 15 foot-diameter test bed Darrieus rotor, Darrieus rotor wind tunnel tests, Savonius rotor wind tunnel tests, blade manufacturing techniques for 15 foot-diameter and 35 foot-diameter wind turbines, static and dynamic structural analysis, production prototype design of a 15 foot-diameter turbine, production prototype design of 35 foot-diameter turbine, and aerodynamic performance studies.
Blackwell, B.F.; Feltz, L.V.; Rightley, E.C.
TECHNICALADVANCES IN EPOXY TECHNOLOGY FOR WIND TURBINE BLADE COMPOSITE FABRICATION George C. Jacob reliability in many demanding applications including components for aerospace and wind turbine blades. While in operation, wind turbine blades are subjected to significant stresses from their movement, wind and other
Wind Turbine Investment and Disinvestment: A Structural Econometric Model
Wind Turbine Investment and Disinvestment: A Structural Econometric Model Jonathan A. Cook C model of wind turbine owners' decisions about whether and when to add new turbines to a pre profit structure for wind producers and evaluate the impact of technology and government policy on wind
Lin, C.-Y. Cynthia
innovati nNREL Computer Models Integrate Wind Turbines with
innovati nNREL Computer Models Integrate Wind Turbines with Floating Platforms Far off the shores for today's seabed-mounted offshore wind turbines. For the United States to tap into these vast offshore wind energy resources, wind turbines must be mounted on floating platforms to be cost effective
Nonlinear Control of a Wind Turbine Sven Creutz Thomsen Kongens Lyngby 2006 #12; Technical describes analysis of various nonlinear control methods for controlling a wind turbine. High speed wind Modeling and analysis 5 2 Model descriptions 7 2.1 Variable speed wind turbine
Portsmouth Abbey School Wind Turbine Wind Farm | Open Energy Information
School Wind Turbine Wind Farm School Wind Turbine Wind Farm Jump to: navigation, search Name Portsmouth Abbey School Wind Turbine Wind Farm Facility Portsmouth Abbey School Wind Turbine Sector Wind energy Facility Type Community Wind Facility Status In Service Owner Portsmouth Abbey School Developer Portsmouth Abbey School Energy Purchaser Portsmouth Abbey School Location Portsmouth RI Coordinates 41.599032°, -71.268688° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":41.599032,"lon":-71.268688,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Harbec Plastic Wind Turbine Wind Farm | Open Energy Information
Harbec Plastic Wind Turbine Wind Farm Harbec Plastic Wind Turbine Wind Farm Jump to: navigation, search Name Harbec Plastic Wind Turbine Wind Farm Facility Harbec Plastic Wind Turbine Sector Wind energy Facility Type Community Wind Facility Status In Service Owner Harbeck Plastic Developer Lorax Energy Systems Energy Purchaser Harbeck Plastic Location Rochester NY Coordinates 43.226039°, -77.361776° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":43.226039,"lon":-77.361776,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Data Analytics Methods in Wind Turbine Design and Operations
This dissertation develops sophisticated data analytic methods to analyze structural loads on, and power generation of, wind turbines. Wind turbines, which convert the kinetic energy in wind into electrical power, are operated within stochastic environments. To account for the influence of environmental factors, we employ a conditional approach by modeling the expectation or distribution of response of interest, be it the structural load or power output, conditional on a set of environmental factors. Because of the different nature associated with the two types of responses, our methods also come in different forms, conducted through two studies. The first study presents a Bayesian parametric model for the purpose of estimating the extreme load on a wind turbine. The extreme load is the highest stress level that the turbine structure would experience during its service lifetime. A wind turbine should be designed to resist such a high load to avoid catastrophic structural failures. To assess the extreme load, turbine structural responses are evaluated by conducting field measurement campaigns or performing aeroelastic simulation studies. In general, data obtained in either case are not sufficient to represent various loading responses under all possible weather conditions. An appropriate extrapolation is necessary to characterize the structural loads in a turbine�s service life. This study devises a Bayesian spline method for this extrapolation purpose and applies the method to three sets of load response data to estimate the corresponding extreme loads at the roots of the turbine blades. In the second study, we propose an additive multivariate kernel method as a new power curve model, which is able to incorporate a variety of environmental factors in addition to merely the wind speed. In the wind industry, a power curve refers to the functional relationship between the power output generated by a wind turbine and the wind speed at the time of power generation. Power curves are used in practice for a number of important tasks including predicting wind power production and assessing a turbine�s energy production efficiency. Nevertheless, actual wind power data indicate that the power output is affected by more than just wind speed. Several other environmental factors, such as wind direction, air density, humidity, turbulence intensity, and wind shears, have potential impact. Yet, in industry practice, as well as in the literature, current power curve models primarily consider wind speed and, with comparatively less frequency, wind speed and direction. Our model provides, conditional on a given environmental condition, both the point estimation and density estimation of the power output. It is able to capture the nonlinear relationships between environmental factors and wind power output, as well as the high-order inter- action effects among some of the environmental factors. To illustrate the application of the new power curve model, we conduct case studies that demonstrate how the new method can help with quantifying the benefit of vortex generator installation, advising pitch control adjustment, and facilitating the diagnosis of faults.
Lee, Giwhyun
Danish Wind Turbine Owners Association | Open Energy Information
Owners Association Owners Association Jump to: navigation, search Name Danish Wind Turbine Owners' Association Place Aarhus C, Denmark Zip DK-8000 Sector Wind energy Product Danish Wind Turbine Ownersâ€(tm) Association is a non-profit, independent association overseeing wind turbine ownersâ€(tm) mutual interests regarding the authorities, political decision-makers, utilities and wind turbine manufacturers. References Danish Wind Turbine Owners' Association[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Danish Wind Turbine Owners' Association is a company located in Aarhus C, Denmark . References ↑ "Danish Wind Turbine Owners' Association" Retrieved from "http://en.openei.org/w/index.php?title=Danish_Wind_Turbine_Owners_Association&oldid=344068
Sinomatech Wind Power Blade aka Sinoma Science Technology Wind Turbine
Sinomatech Wind Power Blade aka Sinoma Science Technology Wind Turbine Sinomatech Wind Power Blade aka Sinoma Science Technology Wind Turbine Blade Co Ltd Jump to: navigation, search Name Sinomatech Wind Power Blade (aka Sinoma Science & Technology Wind Turbine Blade Co Ltd) Place Nanjing, Jiangsu Province, China Zip 210012 Sector Wind energy Product Jiangsu-based wind turbine blade manufactuer. Coordinates 32.0485°, 118.778969° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":32.0485,"lon":118.778969,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Alstom 3-MW Wind Turbine Installed at NWTC (Fact Sheet)
The 3-MW Alstom wind turbine was installed at NREL's NWTC in October 2010. Test data will be used to validate advanced turbine design and analysis tools. NREL signed a Cooperative Research and Development Agreement with Alstom in 2010 to conduct certification testing on the company's 3-MW ECO 100 wind turbine and to validate models of Alstom's unique drivetrain concept. The turbine was installed at NREL's National Wind Technology Center (NWTC) in October 2010 and engineers began certification testing in 2011. Tests to be conducted by NREL include a power quality test to finalize the International Electrotechnical Commission (IEC) requirements for type certification of the 60-Hz unit. The successful outcome of this test will enable Alstom to begin commercial production of ECO 100 in the United States. NREL also will obtain additional measurements of power performance, acoustic noise, and system frequency to complement the 50 Hz results previously completed in Europe. After NREL completes the certification testing on the ECO 100, it will conduct long-term testing to validate gearbox performance to gain a better understanding of the machine's unique ALSTOM PURE TORQUE{trademark} drivetrain concept. In conventional wind turbines, the rotor is supported by the shaft-bearing gearbox assembly. Rotor loads are partially transmitted to the gearbox and may reduce gearbox reliability. In the ALSTOM PURE TORQUE concept, the rotor is supported by a cast frame running through the hub, which transfers bending loads directly to the tower. Torque is transmitted to the shaft through an elastic coupling at the front of the hub. According to Alstom, this system will increase wind turbine reliability and reduce operation and maintenance costs by isolating the gearbox from rotor loads. Gearbox reliability has challenged the wind energy industry for more than two decades. Gearbox failures require expensive and time-consuming replacement, significantly increasing the cost of wind plant operation while reducing the plant's power output and revenue. To solve gearbox reliability issues, NREL launched a Gearbox Reliability Collaborative (GRC) in 2006 and brought together the world's leading turbine manufacturers, consultants, and experts from more than 30 companies and organizations. GRC's goal was to validate the typical design process-from wind turbine system loads to bearing ratings-through a comprehensive dynamometer and field-test program. Design analyses will form a basis for improving reliability of future designs and retrofit packages. Through its study of Alstom's Eco 100 gearbox, NREL can compare its GRC model gearbox with Alstom's and add the results to the GRC database, which is helping to advance more reliable wind turbine technology.
This is a study of the impact that wind turbines have on residential property value. The wind turbines that are the focus of this study are the larger turbines being approximately 389ft tall and producing 1.0+ megawatts each, similar to the one pictured to the right. The study has been broken into three component parts, each looking at the value impact of the wind turbines from a different perspective. The three parts are: (1) a literature study, which reviews and summarizes what has been published on this matter found in the general media; (2) an opinion survey, which was given to area Realtors to learn their opinions on the impact of wind turbines in
Fond Du; Lac Counties Wisconsin
Comparing Single and Multiple Turbine Representations in a Wind Farm Simulation: Preprint
This paper compares single turbine representation versus multiple turbine representation in a wind farm simulation.
Muljadi, E.; Parsons, B.
Spanwise aerodynamic loads on a rotating wind turbine blade
Wind turbine performance and load predictions depend on accurate airfoil performance data. Wind tunnel test data are typically used which accurately describe two-dimensional airfoil performance characteristics. Usually these data are only available for a range of angles of attack from 0 to 15 deg, which excludes the stall characteristics. Airfoils on stall-controlled wind turbines operate in deep stall in medium to high winds. Therefore it is very important to know how the airfoil will perform in these high load conditions. Butterfield et al. have shown that three-dimensional effects and rotation of the blade modify the two-dimensional performance of the airfoil. These effects are modified to different degrees throughout the blade span. The Solar Energy Research Institute (SERI) has conducted a series of tests to measure the spanwise variation of airfoil performance characteristics on a rotating wind turbine blade. Maximum lift coefficients were measured to be 200% greater than wind tunnel results at the 30% span. Stall characteristics were generally modified throughout the span. Lift characteristics were unmodified for low to medium angles of attack. This paper discusses these test results for four spanwise locations. 8 refs., 12 figs.
Butterfield, C.P.; Simms, D.; Musial, W.; Scott, G.
Pioneer Asia Wind Turbines | Open Energy Information
Turbines Turbines Jump to: navigation, search Name Pioneer Asia Wind Turbines Place Madurai, Tamil Nadu, India Zip 625 002 Sector Wind energy Product Madurai-based wind energy division of the Pioneer Group. Coordinates 9.92544°, 78.1192° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":9.92544,"lon":78.1192,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Wind Turbine Design Cost and Scaling Model
Wind Turbine Design Cost Wind Turbine Design Cost and Scaling Model L. Fingersh, M. Hand, and A. Laxson Technical Report NREL/TP-500-40566 December 2006 NREL is operated by Midwest Research Institute ● Battelle Contract No. DE-AC36-99-GO10337 Wind Turbine Design Cost and Scaling Model L. Fingersh, M. Hand, and A. Laxson Prepared under Task No. WER6.0703 Technical Report NREL/TP-500-40566 December 2006 National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, Colorado 80401-3393 303-275-3000 * www.nrel.gov Operated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy by Midwest Research Institute * Battelle Contract No. DE-AC36-99-GO10337 NOTICE This report was prepared as an account of work sponsored by an agency of the United States government.
Methods of making wind turbine rotor blades
A method of manufacturing a root portion of a wind turbine blade includes, in an exemplary embodiment, providing an outer layer of reinforcing fibers including at least two woven mats of reinforcing fibers, providing an inner layer of reinforcing fibers including at least two woven mats of reinforcing fibers, and positioning at least two bands of reinforcing fibers between the inner and outer layers, with each band of reinforcing fibers including at least two woven mats of reinforcing fibers. The method further includes positioning a mat of randomly arranged reinforcing fibers between each pair of adjacent bands of reinforcing fibers, introducing a polymeric resin into the root potion of the wind turbine blade, infusing the resin through the outer layer, the inner layer, each band of reinforcing fibers, and each mat of random reinforcing fibers, and curing the resin to form the root portion of the wind turbine blade.
Livingston, Jamie T. (Pensacola, FL); Burke, Arthur H. E. (Gulf Breeze, FL); Bakhuis, Jan Willem (Nijverdal, NL); Van Breugel, Sjef (Enschede, NL); Billen, Andrew (Daarlerveen, NL)
Built-Environment Wind Turbine Roadmap
Built-Environment Wind Turbine Built-Environment Wind Turbine Roadmap J. Smith, T. Forsyth, K. Sinclair, and F. Oteri Technical Report NREL/TP-5000-50499 November 2012 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. National Renewable Energy Laboratory 15013 Denver West Parkway Golden, Colorado 80401 303-275-3000 * www.nrel.gov Contract No. DE-AC36-08GO28308 Built-Environment Wind Turbine Roadmap J. Smith, T. Forsyth, K. Sinclair, and F. Oteri Prepared under Task No. WE11250 Technical Report NREL/TP-5000-50499 November 2012 NOTICE This report was prepared as an account of work sponsored by an agency of the United States government.
Robust and fault-tolerant linear parameter-varying control of wind turbines Christoffer Sloth a,,1
Robust and fault-tolerant linear parameter-varying control of wind turbines Christoffer Sloth a,,1 Keywords: Wind turbine control Linear parameter-varying (LPV) control Fault-tolerant control Robust control a b s t r a c t High performance and reliability are required for wind turbines to be competitive
Hansen, René Rydhof
A simulation-based planning system for wind turbine construction
Wind turbine construction is a challenging undertaking due to the need to lift heavy loads to high locations in conditions of high and variable wind speeds. These conditions create great risks to contractors during the turbine assembly process. This ...
Dina Atef; Hesham Osman; Moheeb Ibrahim; Khaled Nassar
A doubly-fed permanent magnet generator for wind turbines
Optimum extraction of energy from a wind turbine requires that turbine speed vary with wind speed. Existing solutions to produce constant-frequency electrical output under windspeed variations are undesirable due to ...
Thomas, Andrew J. (Andrew Joseph), 1981-
wind turbine market, along with newly emerging competition from a number of Asian countries, most notably Japan and India.Wind Turbine Equipment Imports Over Time Denmark Euro zone U.K. Japan India
First wind turbine blade delivered to Pantex | National Nuclear...
National Nuclear Security Administration (NNSA)
Work crews began to erect the first of five wind turbines that will make up the Pantex Renewable Energy Project (PREP). The first wind turbine blade was delivered to the site...
Wind turbine data acquisition and analysis system
Under Department of Energy (DOE) sponsorship, Sandia Laboratories has implemented a program to develop vertical-axis wind turbine (VAWT) systems. One aspect of this program has been the development of an instrumented test site adjacent to Sandia Laboratories' Technical Area I on Kirtland Air Force Base. Three VAWTs are now in operation on this test site. This paper describes the data acquisition and analyses system developed to meet the needs of the VAWT test site. The system employs a 16-bit work-length minicomputer as the major element in a stand-alone configuration. A variety of peripheral devices perform the required data acquisition functions and provide for data display and analysis. Included is a disk-based software operating system that supports a mass storage-file system, high-level language, and auxiliary software procedures.
Stiefeld, B.
Quiet airfoils for small and large wind turbines
Thick airfoil families with desirable aerodynamic performance with minimal airfoil induced noise. The airfoil families are suitable for a variety of wind turbine designs and are particularly well-suited for use with horizontal axis wind turbines (HAWTs) with constant or variable speed using pitch and/or stall control. In exemplary embodiments, a first family of three thick airfoils is provided for use with small wind turbines and second family of three thick airfoils is provided for use with very large machines, e.g., an airfoil defined for each of three blade radial stations or blade portions defined along the length of a blade. Each of the families is designed to provide a high maximum lift coefficient or high lift, to exhibit docile stalls, to be relatively insensitive to roughness, and to achieve a low profile drag.
Tangler, James L. (Boulder, CO); Somers, Dan L. (Port Matilda, PA)
Adaptive pitch control for variable speed wind turbines
An adaptive method for adjusting blade pitch angle, and controllers implementing such a method, for achieving higher power coefficients. Average power coefficients are determined for first and second periods of operation for the wind turbine. When the average power coefficient for the second time period is larger than for the first, a pitch increment, which may be generated based on the power coefficients, is added (or the sign is retained) to the nominal pitch angle value for the wind turbine. When the average power coefficient for the second time period is less than for the first, the pitch increment is subtracted (or the sign is changed). A control signal is generated based on the adapted pitch angle value and sent to blade pitch actuators that act to change the pitch angle of the wind turbine to the new or modified pitch angle setting, and this process is iteratively performed.
Johnson, Kathryn E. (Boulder, CO); Fingersh, Lee Jay (Westminster, CO)
Heavy Section Ductile Iron Castings for Use in Wind Turbine ...
However, wind power still accounts for less than 2% of total energy production in the US. One hurdle to producing larger capacity wind turbine generators lies in�...
Error analysis in wind turbine field testing
In wind turbine field testing, one of the most important issues is understanding and accounting for data errors. Extended dynamic testing of wind turbines requires a thorough uncertainty analysis and a regimen of quality assurance steps in order to preserve accuracy. Test objectives need to be identified to determine the accuracy requirements of any data measurement, collection, and analysis process. Frequently, the uncertainty analysis reveals that the major sources of error can be allowed for with careful calibration and signal drift tracking procedures. This paper offers a basis for the discussion and development of a repeatable and accurate process to track errors and account for them in data processing.
McNiff, B [McNiff Light Industries, Carlisle, MA (United States); Simms, D [National Renewable Energy Lab., Golden, CO (United States)
Dynamic stall on wind turbine blades
Dynamic loads must be predicted accurately in order to estimate the fatigue life of wind turbines operating in turbulent environments. Dynamic stall contributes to increased dynamic loads during normal operation of all types of horizontal-axis wind turbine (HAWTs). This report illustrates how dynamic stall varies throughout the blade span of a 10 m HAWT during yawed and unyawed operating conditions. Lift, drag, and pitching moment coefficients during dynamics stall are discussed. Resulting dynamic loads are presented, and the effects of dynamic stall on yaw loads are demonstrated using a yaw loads dynamic analysis (YAWDYN). 12 refs., 22 figs., 1 tab.
Butterfield, C.P.; Simms, D.; Scott, G. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); Hansen, A.C. [Utah Univ., Salt Lake City, UT (United States)] [Utah Univ., Salt Lake City, UT (United States)
Amplitude modulation of wind turbine noise
Due to swish and thump amplitude modulation, the noise of wind turbines cause more annoyance than other environmental noise of the same average level. The wind shear accounts for the thump modulation (van den Berg effect). Making use of the wind speed measurements at the hub height, as well as at the top and the bottom of the rotor disc (Fig.1), the non-standard wind profile is applied. It causes variations in the A-weighted sound pressure level, LpA. The difference between the maximum and minimum of LpA characterizes thump modulation (Fig.2).
The Effect of Wind Speed and Electric Rates On Wind Turbine Economics
The Effect of Wind Speed and Electric Rates On Wind Turbine Economics Economics of wind power depends mainly on the wind speeds and the turbine make and model. Definition: Simple Payback The "Simple period of a small wind power project. All the figures are per turbine, so it can be used for a one, two
Uncovering wind turbine properties through two-dimensional stochastic modeling of wind dynamics
Using a method for stochastic data analysis, borrowed from statistical physics, we analyze synthetic data from a Markov chain model that reproduces measurements of wind speed and power production in a wind park in Portugal. From the theoretical point of view we argue that our methods can be used to extract unknown functional relations between two variables. We first show that indeed our analysis retrieves the power performance curve, which yields the relationship between wind speed and power production and discuss how such procedure can be extended for extracting functional relationships between pairs of physical variables in general. Second, we show how specific features, such as the turbine rated wind speed or the descriptive wind speed statistics, can be related with the equations describing the evolution of power production and wind speed at single wind turbines.
Raischel, Frank; Lopes, Vitor V; Lind, Pedro G
Wind Turbine System State Awareness - Energy Innovation Portal
Technology Marketing Summary Researchers at the Los Alamos National Laboratory Intelligent Wind Turbine Program are developing a multi-physics ...
Establishment of Small Wind Turbine Regional Test Centers (Presentation)
This presentation offers an overview of the Regional Test Centers project for Small Wind Turbine testing and certification.
Sinclair, K.
Modal Dynamics of Large Wind Turbines with Different Support Structures
This paper presents modal dynamics of floating-platform-supported and monopile-supported offshore wind turbines.
Bir, G.; Jonkman, J.
Low Wind Speed Technology Phase II: LIDAR for Turbine Control
This fact sheet describes NREL's subcontract with QinetiQ to conduct a study on LIDAR systems for wind turbines.
Strategies for Refining IEC 61400-2: Wind Turbine Generator Systems - Part 2: Safety of Small Wind Turbines: Preprint
This paper provides a status of the changes currently being made by IEC Maintenance Team 02 (MT02) to the existing IEC 61400-2 ''Safety of small wind turbines.'' In relation to the work done by IEC MT02, work has been done by NREL and Windward Engineering under the DOE/NREL Small Wind Turbine (SWT) Project. Aeroelastic models were built and measurements taken on a Whisper H40 turbine and an AOC 15/50. Results from this study were used to verify the simple design equations. This verification will be used to evaluate how changes made in the design load estimation section of the standard work out for a broad range of turbine configurations. The work presented here builds on work performed by Van Hulle (1996).
van Dam, J. J. D. (Energy Research Centre of the Netherlands); Forsyth, T. L. (National Renewable Energy Laboratory); Hansen, A. C. (Windward Engineering LLC)
EFFECTS OF FIBER WAVINESS ON COMPOSITES FOR WIND TURBINE BLADES J.F. Mandell D.D. Samborsky and L Composite materials of interest for wind turbine blades use relatively low cost fibers, resins and processes WORDS: Composite Materials, Fiber Waviness, Compressive Strength #12;1. INTRODUCTION Wind turbine blades
Understanding Trends inUnderstanding Trends in Wind Turbine Prices
(worldwide) Polynomial trend line e(2010$/kW 400 600 800 1,000 TurbinePric Recent wind turbine price quotes 0Understanding Trends inUnderstanding Trends in Wind Turbine Prices OOver the Past Decade Mark Division · Energy Analysis Department Efficiency and Renewable Energy (Wind & Water Power Program) under
Development of Wind Turbines Prototyping Software Under Matlab/Simulink
204 1 Development of Wind Turbines Prototyping Software Under Matlab/Simulink® Through present the development of a wind turbine prototyping software under Matlab/Simulink® through and the end of 1999, around 75% of all new grid-connected wind turbines worldwide were installed in Europe [3
Paris-Sud XI, Université de
Assessing the Impacts of Reduced Noise Operations of Wind Turbines
i LBNL-3562E Assessing the Impacts of Reduced Noise Operations of Wind Turbines on Neighbor Operations of Wind Turbines on Neighbor Annoyance: A Preliminary Analysis in Vinalhaven, Maine Prepared from the turbines is unwelcome and annoying. Fox Islands Wind, the owner of the facility, hypothesized
IMPLEMENTATION OF WIND TURBINE CONTROLLERS W.E.Leithead
IMPLEMENTATION OF WIND TURBINE CONTROLLERS D.J.Leith W.E.Leithead Department of Electronic-speed wind turbines are considered, namely, (1) accommodation of the strongly nonlinear rotor aerodynamics derived and extended to cater for all wind turbine configurations. A rigorous stability analysis
Fast Verification of Wind Turbine Power Summary of Project Results
a wind turbine's design phase, the power curve can be predicted using analytical techniques such as Blade using a single cup anemometer at the wind turbine's hub height and it is assumed that this measurementFast Verification of Wind Turbine Power Curves: Summary of Project Results by: Cameron Brown s
Duration Test Report for the Entegrity EW50 Wind Turbine
This report summarizes the results of a duration test that NREL conducted on the Entegrity EW50 wind turbine. This test was conducted in accordance with the International Electrotechnical Commissions' (IEC) standard, Wind Turbine Generator System Part 2: Design requirements for small wind turbines, IEC 61400-2 Ed.2.0, 2006-03.
Optimizing wind turbine control system parameters
The impending expiration of the levelized period in the Interim Standard Offer Number 4 (ISO4) utility contracts for purchasing wind-generated power in California mandates, more than ever, that windplants be operated in a cost-effective manner. Operating plans and approaches are needed that maximize the net revenue from wind parks--after accounting for operation and maintenance costs. This paper describes a design tool that makes it possible to tailor a control system of a wind turbine (WT) to maximize energy production while minimizing the financial consequences of fatigue damage to key structural components. Plans for code enhancements to include expert systems and fuzzy logic are discussed, and typical results are presented in which the code is applied to study the controls of a generic Danish 15-m horizontal axis wind turbine (HAWT).
Schluter, L.L. [Sandia National Labs., Albuquerque, NM (United States); Vachon, W.A. [Vachon (W.A.) and Associates, Inc., Manchester, MA (United States)
Estimated global ocean wind power potential from QuikSCAT observations, accounting for turbine characteristics and siting
for off- shore wind turbines in Europe and North America,of wind power and wind turbine characteristics, Renewablea multi?megawatt wind turbine, Renewable Energy, Matthews,
Capps, Scott B; Zender, Charles S
Dynamically Adjustable Wind Turbine Blades: Adaptive Turbine Blades, Blown Wing Technology for Low-Cost Wind Power
Broad Funding Opportunity Announcement Project: Caitin is developing wind turbines with a control system that delivers compressed air from special slots located in the surface of its blades. The compressed air dynamically adjusts the aerodynamic performance of the blades, and can essentially be used to control lift, drag, and ultimately power. This control system has been shown to exhibit high levels of control in combination with an exceptionally fast response rate. The deployment of such a control system in modern wind turbines would lead to better management of the load on the system during peak usage, allowing larger blades to be deployed with a resulting increase in energy production.
Operation of a third generation wind turbine
A modern wind turbine was installed on May 26, 1982, at the USDA Conservation and Production Research Laboratory, Bushland, Texas. This wind machine was used to provide electrical energy for irrigation pumping and other agricultural loads. The wind turbine purchased for this research is an Enertech Model 44, manufactured by Enertech Corporation, Norwich, Vermont. The horizontal-axis wind turbine has a 13.4 m diameter, three-bladed, fixed-pitch rotor on a 24.4-m tower. The blades are laminated epoxy-wood, and are attached to a steel hub. A 25-kW induction generator provides 240 V, 60 Hz, single-phase electrical power. The wind turbine operated 64 percent of the time, while being available to operate over 94 percent of the time. The unit had a net energy production of over 80,000 kWh in an average windspeed of 5.9 m/s at a height of 10 m in a 16-month period. The blade pitch was originally offset two degrees from design to maintain power production within the limitations of the gearbox, generator, and brakes. A maximum output of 23.2 kW averaged over a 15-second period indicated that with a new brake, the system was capable of handling more power. After a new brake was installed, the blade pitch was changed to one degree from design. The maximum power output measured after the pitch change was 29.3 kW. Modified blade tip brakes were installed on the wind turbine on July 7, 1983. These tip brakes increased power production at lower windspeeds while reducing power at higher windspeeds.
Vosper, F.C.; Clark, R.N.
A Methodology for Assessment of Wind Turbine Noise Generation
The detailed analysis of a series of acoustic measurements taken near several large wind turbines (100 kWand above) has identified the maximum acoustic energy as being concentrated in the low-frequency audible and subaudible ranges, usually less than 100 Hz. These measurements have also shown any reported community annoyance associated with turbine operations has often been related to the degree of coherent impulsiveness present and the subsequent harmonic coupling of acoustic energy to residential structures. Thus, one technique to assess the annoyance potential of a given wind turbine design is to develop a method which quantifies this degree of impulsiveness or coherency in the radiated acoustic energy spectrum under a wide range of operating conditions. Experience has also shown the presence of annoying conditions is highly time dependent and nonstationary, and, therefore, any attempts to quantify or at least classify wind turbine designs in terms of their noise annoyance potential must be handled within the proper probabilistic framework. A technique is described which employs multidimensional, joint probability analysis to establish the expected coincidence of acoustic energy levels in a contiguous sequence of octave frequency bands which have been chosen because of their relationship to common structural resonant frequencies in residential buildings. Evidence is presented to justify the choice of these particular bands. Comparisons of the acoustic performance and an estimate of the annoyance potential of several large wind turbine designs using this technique is also discussed.
N. D. Kelley; R. R. Hemphill; M. E. Mckenna
Although only a small contributor to total electricity production needs, built-environment wind turbines (BWTs) nonetheless have the potential to influence the public's consideration of renewable energy, and wind energy in particular. Higher population concentrations in urban environments offer greater opportunities for project visibility and an opportunity to acquaint large numbers of people to the advantages of wind projects on a larger scale. However, turbine failures will be equally visible and could have a negative effect on public perception of wind technology. This roadmap provides a framework for achieving the vision set forth by the attendees of the Built-Environment Wind Turbine Workshop on August 11 - 12, 2010, at the U.S. Department of Energy's National Renewable Energy Laboratory. The BWT roadmap outlines the stakeholder actions that could be taken to overcome the barriers identified. The actions are categorized as near-term (0 - 3 years), medium-term (4 - 7 years), and both near- and medium-term (requiring immediate to medium-term effort). To accomplish these actions, a strategic approach was developed that identifies two focus areas: understanding the built-environment wind resource and developing testing and design standards. The authors summarize the expertise and resources required in these areas.
Smith, J.; Forsyth, T.; Sinclair, K.; Oteri, F.
Small Wind Turbine Applications: Current Practice in Colorado
Numerous small wind turbines are being used by homeowners in Colorado. Some of these installations are quite recent while others date back to the federal tax-credit era of the early 1980s. Through visits with small wind turbine owners in Colorado, I have developed case studies of six small wind energy applications focusing on the wind turbine technology, wind turbine siting, the power systems and electric loads, regulatory issues, and motivations about wind energy. These case studies offer a glimpse into the current state-of-the-art of small-scale wind energy and provide some insight into issues affecting development of a wider market.
Green, J.
Wind turbine reliability :understanding and minimizing wind turbine operation and maintenance costs.
Wind turbine system reliability is a critical factor in the success of a wind energy project. Poor reliability directly affects both the project's revenue stream through increased operation and maintenance (O&M) costs and reduced availability to generate power due to turbine downtime. Indirectly, the acceptance of wind-generated power by the financial and developer communities as a viable enterprise is influenced by the risk associated with the capital equipment reliability; increased risk, or at least the perception of increased risk, is generally accompanied by increased financing fees or interest rates. This paper outlines the issues relevant to wind turbine reliability for wind turbine power generation projects. The first sections describe the current state of the industry, identify the cost elements associated with wind farm O&M and availability and discuss the causes of uncertainty in estimating wind turbine component reliability. The latter sections discuss the means for reducing O&M costs and propose O&M related research and development efforts that could be pursued by the wind energy research community to reduce cost of energy.
Walford, Christopher A. (Global Energy Concepts. Kirkland, WA)
Hydrogen Storage in Wind Turbine Towers
Low-cost hydrogen storage is recognized as a cornerstone of a renewables-hydrogen economy. Modern utility-scale wind turbine towers are typically conical steel structures that, in addition to supporting the rotor, could be used to store hydrogen. This study has three objectives: (1) Identify the paramount considerations associated with using a wind turbine tower for hydrogen storage; (2)Propose and analyze a cost-effective design for a hydrogen-storing tower; and (3) Compare the cost of storage in hydrogen towers to the cost of storage in conventional pressure vessels. The paramount considerations associated with a hydrogen tower are corrosion (in the form of hydrogen embrittlement) and structural failure (through bursting or fatigue life degradation). Although hydrogen embrittlement (HE) requires more research, it does not appear to prohibit the use of turbine towers for hydrogen storage. Furthermore, the structural modifications required to store hydrogen in a tower are not cost prohibitive.
Kottenstette, R.; Cotrell, J.
Root region airfoil for wind turbine
A thick airfoil for the root region of the blade of a wind turbine. The airfoil has a thickness in a range from 24%-26% and a Reynolds number in a range from 1,000,000 to 1,800,000. The airfoil has a maximum lift coefficient of 1.4-1.6 that has minimum sensitivity to roughness effects.
Wooden wind turbine blade manufacturing process
A wooden wind turbine blade is formed by laminating wood veneer in a compression mold having the exact curvature needed for one side of the blade, following which the other side of the blade is ground flat along its length but twisted with respect to the blade axis.
Coleman, Clint (Warren, VT)
A sensorless control for wind turbine
This paper presents a sensorless control for a stall regulated variable speed wind turbine, where the speed reference is obtained from the estimated aerodynamic torque. The LQG/LTR methodology is applied to the design of an optimal discrete-time feedback ...
Ronilson Rocha
Wind Turbine Tribology Seminar - A Recap
Tribology is the science and engineering of interacting surfaces in relative motion. It includes the study and application of the principles of friction, lubrication, and wear. It is an important phenomenon that not only impacts the design and operation of wind turbine gearboxes, but also their subsequent maintenance requirements and overall reliability. With the major growth and increasing dependency on renewable energy, mechanical reliability is an extremely important issue. The Wind Turbine Tribology Seminar was convened to explore the state-of-the-art in wind turbine tribology and lubricant technologies, raise industry awareness of a very complex topic, present the science behind each technology, and identify possible R&D areas. To understand the background of work that had already been accomplished, and to consolidate some level of collective understanding of tribology by acknowledged experts, the National Renewable Energy Laboratory (NREL), Argonne National Laboratory (ANL), and the U.S. Department of Energy (DOE) hosted a wind turbine tribology seminar. It was held at the Renaissance Boulder Flatiron Hotel in Broomfield, Colorado on November 15-17, 2011. This report is a summary of the content and conclusions. The presentations given at the meeting can be downloaded. Interested readers who were not at the meeting may wish to consult the detailed publications listed in the bibliography section, obtain the cited articles in the public domain, or contact the authors directly.
Errichello, R.; Sheng, S.; Keller, J.; Greco, A.
Status of the large wind turbine handbook
The site-selection strategy presented here and in the LWH is conservative, partially because utilities are conservative. They should be. The large-scale generation of electricity by wind turbine generators is an unproven technology. It is assumed that wind characteristics at a site will have to be thoroughly documented. This is because the nature of the wind at the site not only governs the energy output of the WECS farm, but also affects the service life of the wind equipment and both scheduled and unscheduled maintenance costs. Perhaps as experience is gained, the site-selection process can be simplified. Certain steps may be found unnecessary, or requirements on the quantity and quality of wind data collected at each step may be relaxed; however, at this stage of wind energy development, a conservative approach seems prudent.
Heister, T. R.; Pennell, W. T.
Wind Turbine Modeling for Computational Fluid Dynamics: December 2010 - December 2012
With the shortage of fossil fuel and the increasing environmental awareness, wind energy is becoming more and more important. As the market for wind energy grows, wind turbines and wind farms are becoming larger. Current utility-scale turbines extend a significant distance into the atmospheric boundary layer. Therefore, the interaction between the atmospheric boundary layer and the turbines and their wakes needs to be better understood. The turbulent wakes of upstream turbines affect the flow field of the turbines behind them, decreasing power production and increasing mechanical loading. With a better understanding of this type of flow, wind farm developers could plan better-performing, less maintenance-intensive wind farms. Simulating this flow using computational fluid dynamics is one important way to gain a better understanding of wind farm flows. In this study, we compare the performance of actuator disc and actuator line models in producing wind turbine wakes and the wake-turbine interaction between multiple turbines. We also examine parameters that affect the performance of these models, such as grid resolution, the use of a tip-loss correction, and the way in which the turbine force is projected onto the flow field.
Tossas, L. A. M.; Leonardi, S.
Cost Study for Large Wind Turbine Blades
The cost study for large wind turbine blades reviewed three blades of 30 meters, 50 meters, and 70 meters in length. Blade extreme wind design loads were estimated in accordance with IEC Class I recommendations. Structural analyses of three blade sizes were performed at representative spanwise stations assuming a stressed shell design approach and E-glass/vinylester laminate. A bill of materials was prepared for each of the three blade sizes using the laminate requirements prepared during the structural analysis effort. The labor requirements were prepared for twelve major manufacturing tasks. TPI Composites developed a conceptual design of the manufacturing facility for each of the three blade sizes, which was used for determining the cost of labor and overhead (capital equipment and facilities). Each of the three potential manufacturing facilities was sized to provide a constant annual rated power production (MW per year) of the blades it produced. The cost of the production tooling and overland transportation was also estimated. The results indicate that as blades get larger, materials become a greater proportion of total cost, while the percentage of labor cost is decreased. Transportation costs decreased as a percentage of total cost. The study also suggests that blade cost reduction efforts should focus on reducing material cost and lowering manufacturing labor, because cost reductions in those areas will have the strongest impact on overall blade cost.
Small Wind Guidebook/What Size Wind Turbine Do I Need | Open Energy
What Size Wind Turbine Do I Need What Size Wind Turbine Do I Need < Small Wind Guidebook Jump to: navigation, search Print PDF WIND ENERGY STAKEHOLDER ENGAGEMENT & OUTREACHSmall Wind Guidebook Home WindTurbine-icon.png Small Wind Guidebook * Introduction * First, How Can I Make My Home More Energy Efficient? * Is Wind Energy Practical for Me? * What Size Wind Turbine Do I Need? * What Are the Basic Parts of a Small Wind Electric System? * What Do Wind Systems Cost? * Where Can I Find Installation and Maintenance Support? * How Much Energy Will My System Generate? * Is There Enough Wind on My Site? * How Do I Choose the Best Site for My Wind Turbine? * Can I Connect My System to the Utility Grid? * Can I Go Off-Grid? * State Information Portal * Glossary of Terms * For More Information What Size Wind Turbine Do I Need?
Wind Turbine Asset Management Technology Assessment
Wind power is one of the fastest growing generation resources in the United States and elsewhere in the world. As of December 2009, the installed wind capacity was more than 35 GW in the United States and more than 160 GW worldwide, and it is forecast to nearly triple to 100 GW and 450 GW, respectively, by 2014. The industry considers the major wind turbine components to be mature commercial technology. However, failures of gearboxes, blades, electrical controls, and other components continue to reduce t...
Fish schooling as a basis for vertical axis wind turbine farm design
Most wind farms consist of horizontal axis wind turbines (HAWTs) due to the high power coefficient (mechanical power output divided by the power of the free-stream air through the turbine cross-sectional area) of an isolated turbine. However when in close proximity to neighbouring turbines, HAWTs suffer from a reduced power coefficient. In contrast, previous research on vertical axis wind turbines (VAWTs) suggests that closely-spaced VAWTs may experience only small decreases (or even increases) in an individual turbine's power coefficient when placed in close proximity to neighbours, thus yielding much higher power outputs for a given area of land. A potential flow model of inter-VAWT interactions is developed to investigate the effect of changes in VAWT spatial arrangement on the array performance coefficient, which compares the expected average power coefficient of turbines in an array to a spatially-isolated turbine. A geometric arrangement based on the configuration of shed vortices in the wake of schooli...
Whittlesey, Robert W; Dabiri, John O
Effects of blade configurations on flow distribution and power output of a Zephyr vertical axis wind turbine
Numerical simulations with FLUENT software were conducted to investigate the fluid flow through a novel vertical axis wind turbine (VAWT). Simulation of flow through the turbine rotor was performed with the aim of predicting the performance characteristics ... Keywords: blade configuration, power output, rotor, simulation, vertical axis wind turbine
J. O. Ajedegba; G. F. Naterer; M. A. Rosen; E. Tsang
Using Machine Learning to Create Turbine Performance Models (Presentation)
Wind turbine power output is known to be a strong function of wind speed, but is also affected by turbulence and shear. In this work, new aerostructural simulations of a generic 1.5 MW turbine are used to explore atmospheric influences on power output. Most significant is the hub height wind speed, followed by hub height turbulence intensity and then wind speed shear across the rotor disk. These simulation data are used to train regression trees that predict the turbine response for any combination of wind speed, turbulence intensity, and wind shear that might be expected at a turbine site. For a randomly selected atmospheric condition, the accuracy of the regression tree power predictions is three times higher than that of the traditional power curve methodology. The regression tree method can also be applied to turbine test data and used to predict turbine performance at a new site. No new data is required in comparison to the data that are usually collected for a wind resource assessment. Implementing the method requires turbine manufacturers to create a turbine regression tree model from test site data. Such an approach could significantly reduce bias in power predictions that arise because of different turbulence and shear at the new site, compared to the test site.
Investigation of aerodynamic braking devices for wind turbine applications
This report documents the selection and preliminary design of a new aerodynamic braking system for use on the stall-regulated AWT-26/27 wind turbines. The goal was to identify and design a configuration that offered improvements over the existing tip brake used by Advanced Wind Turbines, Inc. (AWT). Although the design objectives and approach of this report are specific to aerodynamic braking of AWT-26/27 turbines, many of the issues addressed in this work are applicable to a wider class of turbines. The performance trends and design choices presented in this report should be of general use to wind turbine designers who are considering alternative aerodynamic braking methods. A literature search was combined with preliminary work on device sizing, loads and mechanical design. Candidate configurations were assessed on their potential for benefits in the areas of cost, weight, aerodynamic noise, reliability and performance under icing conditions. As a result, two configurations were identified for further study: the {open_quotes}spoiler-flap{close_quotes} and the {open_quotes}flip-tip.{close_quotes} Wind tunnel experiments were conducted at Wichita State University to evaluate the performance of the candidate aerodynamic brakes on an airfoil section representative of the AWT-26/27 blades. The wind tunnel data were used to predict the braking effectiveness and deployment characteristics of the candidate devices for a wide range of design parameters. The evaluation was iterative, with mechanical design and structural analysis being conducted in parallel with the braking performance studies. The preliminary estimate of the spoiler-flap system cost was $150 less than the production AWT-26/27 tip vanes. This represents a reduction of approximately 5 % in the cost of the aerodynamic braking system. In view of the preliminary nature of the design, it would be prudent to plan for contingencies in both cost and weight.
Griffin, D.A. [R. Lynette & Associates, Seattle, WA (United States)
Response of a Vertical Axis Wind Turbine to Time Varying Wind Conditions found within the Urban
Response of a Vertical Axis Wind Turbine to Time Varying Wind Conditions found within the Urban, 2010 PP 389401 389 ABSTRACT Experimental testing of a vertical axis wind turbine within the urban of the turbine. Temporal variation of the wind with respect to the direction and velocity fluctuations
RESEARCH ARTICLE Dynamic wind loads and wake characteristics of a wind turbine
RESEARCH ARTICLE Dynamic wind loads and wake characteristics of a wind turbine model of the unsteady vortex and turbulent flow structures in the near wake of a horizontal axis wind turbine model.e., aerodynamic forces and bending moments) acting on the wind turbine model by using a high-sensitive force
Hu, Hui
Duration Test Report for the Viryd CS8 Wind Turbine
This report summarizes the results of a duration noise test that the National Renewable Energy Laboratory (NREL) conducted on the Viryd CS8 wind turbine. This test was conducted in accordance with Clause 9.4 of the International Electrotechnical Commission's (IEC) standard, Wind turbines - Part 2: Design requirements for small wind turbines, IEC 61400-2 Ed. 2.0:2006-03. NREL researchers evaluated the turbine based on structural integrity and material degradation, quality of environmental protection, and dynamic behavior.
Probabilistic fatigue methodology and wind turbine reliability
Wind turbines subjected to highly irregular loadings due to wind, gravity, and gyroscopic effects are especially vulnerable to fatigue damage. The objective of this study is to develop and illustrate methods for the probabilistic analysis and design of fatigue-sensitive wind turbine components. A computer program (CYCLES) that estimates fatigue reliability of structural and mechanical components has been developed. A FORM/SORM analysis is used to compute failure probabilities and importance factors of the random variables. The limit state equation includes uncertainty in environmental loading, gross structural response, and local fatigue properties. Several techniques are shown to better study fatigue loads data. Common one-parameter models, such as the Rayleigh and exponential models are shown to produce dramatically different estimates of load distributions and fatigue damage. Improved fits may be achieved with the two-parameter Weibull model. High b values require better modeling of relatively large stress ranges; this is effectively done by matching at least two moments (Weibull) and better by matching still higher moments. For this purpose, a new, four-moment {open_quotes}generalized Weibull{close_quotes} model is introduced. Load and resistance factor design (LRFD) methodology for design against fatigue is proposed and demonstrated using data from two horizontal-axis wind turbines. To estimate fatigue damage, wind turbine blade loads have been represented by their first three statistical moments across a range of wind conditions. Based on the moments {mu}{sub 1}{hor_ellipsis}{mu}{sub 3}, new {open_quotes}quadratic Weibull{close_quotes} load distribution models are introduced. The fatigue reliability is found to be notably affected by the choice of load distribution model.
Lange, C.H. [Stanford Univ., CA (United States)
Original article: Comparison of maximum peak power tracking algorithms for a small wind turbine
This paper reviews maximum power point tracking (MPPT) algorithms dedicated for small wind turbines (SWTs). Many control strategies with different features are available and it is very important to select proper one in order to achieve best performance ... Keywords: Maximum power point tracking (MPPT), PMSG, Small wind turbine (SWT)
R. Kot, M. Rolak, M. Malinowski
Wind turbine reliability : understanding and minimizing wind turbine operation and maintenance costs.
Wind turbine system reliability is a critical factor in the success of a wind energy project. Poor reliability directly affects both the project's revenue stream through increased operation and maintenance (O&M) costs and reduced availability to generate power due to turbine downtime. Indirectly, the acceptance of wind-generated power by the financial and developer communities as a viable enterprise is influenced by the risk associated with the capital equipment reliability; increased risk, or at least the perception of increased risk, is generally accompanied by increased financing fees or interest rates. Cost of energy (COE) is a key project evaluation metric, both in commercial applications and in the U.S. federal wind energy program. To reflect this commercial reality, the wind energy research community has adopted COE as a decision-making and technology evaluation metric. The COE metric accounts for the effects of reliability through levelized replacement cost and unscheduled maintenance cost parameters. However, unlike the other cost contributors, such as initial capital investment and scheduled maintenance and operating expenses, costs associated with component failures are necessarily speculative. They are based on assumptions about the reliability of components that in many cases have not been operated for a complete life cycle. Due to the logistical and practical difficulty of replacing major components in a wind turbine, unanticipated failures (especially serial failures) can have a large impact on the economics of a project. The uncertainty associated with long-term component reliability has direct bearing on the confidence level associated with COE projections. In addition, wind turbine technology is evolving. New materials and designs are being incorporated in contemporary wind turbines with the ultimate goal of reducing weight, controlling loads, and improving energy capture. While the goal of these innovations is reduction in the COE, there is a potential impact on reliability whenever new technologies are introduced. While some of these innovations may ultimately improve reliability, in the short term, the technology risks and the perception of risk will increase. The COE metric used by researchers to evaluate technologies does not address this issue. This paper outlines the issues relevant to wind turbine reliability for wind turbine power generation projects. The first sections describe the current state of the industry, identify the cost elements associated with wind farm O&M and availability and discuss the causes of uncertainty in estimating wind turbine component reliability. The latter sections discuss the means for reducing O&M costs and propose O&M related research and development efforts that could be pursued by the wind energy research community to reduce COE.
Alternative Design Study Report: WindPACT Advanced Wind Turbine Drive Train Designs Study; November 1, 2000 -- February 28, 2002
This report presents the Phase I results of the National Renewable Energy Laboratory's (NREL's) WindPACT (Wind Partnership for Advanced Component Technologies) Advanced Wind Turbine Drive Train Designs Study. Global Energy Concepts, LLC performed this work under a subcontract with NREL. The purpose of the WindPACT project is to identify technology improvements that will enable the cost of energy (COE) from wind turbines to be reduced. Other parts of the WindPACT project have examined blade and logistics scaling, balance-of-station costs, and rotor design. This study was designed to investigate innovative drive train designs.
Poore, R.; Lettenmaier, T.
Small Wind Guidebook/How Do I Choose the Best Site for My Wind Turbine |
Small Wind Guidebook/How Do I Choose the Best Site for My Wind Turbine Small Wind Guidebook/How Do I Choose the Best Site for My Wind Turbine < Small Wind Guidebook Jump to: navigation, search Print PDF WIND ENERGY STAKEHOLDER ENGAGEMENT & OUTREACHSmall Wind Guidebook Home WindTurbine-icon.png Small Wind Guidebook * Introduction * First, How Can I Make My Home More Energy Efficient? * Is Wind Energy Practical for Me? * What Size Wind Turbine Do I Need? * What Are the Basic Parts of a Small Wind Electric System? * What Do Wind Systems Cost? * Where Can I Find Installation and Maintenance Support? * How Much Energy Will My System Generate? * Is There Enough Wind on My Site? * How Do I Choose the Best Site for My Wind Turbine? * Can I Connect My System to the Utility Grid? * Can I Go Off-Grid? * State Information Portal * Glossary of Terms
Feasibility of Floating Platform Systems for Wind Turbines: Preprint
This paper provides a general technical description of several types of floating platforms for wind turbines. Platform topologies are classified into multiple- or single-turbine floaters and by mooring method. Platforms using catenary mooring systems are contrasted to vertical mooring systems and the advantages and disadvantages are discussed. Specific anchor types are described in detail. A rough cost comparison is performed for two different platform architectures using a generic 5-MW wind turbine. One platform is a Dutch study of a tri-floater platform using a catenary mooring system, and the other is a mono-column tension-leg platform developed at the National Renewable Energy Laboratory. Cost estimates showed that single unit production cost is $7.1 M for the Dutch tri-floater, and $6.5 M for the NREL TLP concept. However, value engineering, multiple unit series production, and platform/turbine system optimization can lower the unit platform costs to $4.26 M and $2.88 M, respectively, with significant potential to reduce cost further with system optimization. These foundation costs are within the range necessary to bring the cost of energy down to the DOE target range of $0.05/kWh for large-scale deployment of offshore floating wind turbines.
Musial, W.; Butterfield, S.; Boone, A.
Property:WindTurbineManufacturer | Open Energy Information
WindTurbineManufacturer WindTurbineManufacturer Jump to: navigation, search This is a property of type Page. Pages using the property "WindTurbineManufacturer" Showing 25 pages using this property. (previous 25) (next 25) 3 3-D Metals + Northern Power Systems + A AB Tehachapi Wind Farm + Vestas + AFCEE MMR Turbines + GE Energy + AG Land 1 + GE Energy + AG Land 2 + GE Energy + AG Land 3 + GE Energy + AG Land 4 + GE Energy + AG Land 5 + GE Energy + AG Land 6 + GE Energy + AVTEC + Northern Power Systems + Adair Wind Farm I + Vestas + Adair Wind Farm II + Siemens + Adams Wind Project + Alstom + Aeroman Repower Wind Farm + GE Energy + Affinity Wind Farm + Suzlon Energy Company + Agassiz Beach Wind Farm + Vestas + Agriwind Wind Farm + Suzlon Energy Company + Ainsworth Wind Energy Facility + Vestas +
Innovation and the price of wind energy in the US. � Energythe impact of energy price changes on wind turbine prices.Costs 3.6 Energy Prices Life-cycle analyses of wind projects
and the issues. � Wind Energy, 7(4), 373�392. Somerville, P.turbines. � European Wind Energy Conference and Exhibition,Athens, Greece. European Wind Energy Association, He, X. (
Capps et al. Wind Power Sensitivity to Turbine Characteristics Sensitivity of Southern California Wind Power to Turbine
functions. However, for the installation of a single or small cluster of turbines, a wind developer may find phase of a wind project includes monitoring and evaluating the local wind resource, determining possible turbine locations, and estimating the economic feasibility of a wind project. It may also include
Hall, Alex
Advanced Airfoils for Wind Turbines: Office of Power Technologies (OPT) Success Stories Series Fact Sheet
Program Program Office of Geothermal and Wind Technologies Blades are where the turbine meets the wind. Turbine blades take advantage of aero- dynamics to extract the wind's energy, which can then be converted to useful electricity. Airfoils-the cross-sectional shape of the blades-determine the aerodynamic forces on blades. They are key to blade design. In the seventies, the young and fast-growing U.S. wind industry used airfoil designs from airplane wings to design turbine blades because those airfoil designs were widely available, and engineers understood how they performed on aircraft. Airfoils specifically designed for wind turbines did not yet exist. The industry quickly learned, however, how harsh the operating environment is for wind turbines as compared to that for airplanes.
Cambridge Danehy Park Wind Turbine Preliminary Project Assessment
.0 100.0 120.0 0 10 20 30 40 Noise Level (dBA) Distance from Wind Turbine (m) SS P20, NP100, and P500 ACambridge Danehy Park Wind Turbine Preliminary Project Assessment Overview MIT Wind Energy Projects 4 / 25 2.5 / 25 Rated Wind Speed (m/s) 13 10 14.5 ~15 12 The above turbines were chosen to provide
Understanding Wind Turbine Price Trends in the U.S. Over the Past Decade
consequent impacts on wind turbine and wind energy pricing.Bloomberg NEF�). 2011c. Wind Turbine Price Index, Issue V.Understanding Trends in Wind Turbine Prices Over the Past
Offshore Wind Turbines - Estimated Noise from Offshore Wind Turbine, Monhegan Island, Maine: Environmental Effects of Offshore Wind Energy Development
Deep C Wind, a consortium headed by the University of Maine will test the first U.S. offshore wind platforms in 2012. In advance of final siting and permitting of the test turbines off Monhegan Island, residents of the island off Maine require reassurance that the noise levels from the test turbines will not disturb them. Pacific Northwest National Laboratory, at the request of the University of Maine, and with the support of the U.S. Department of Energy Wind Program, modeled the acoustic output of the planned test turbines.
Wind turbine reliability database update.
This report documents the status of the Sandia National Laboratories' Wind Plant Reliability Database. Included in this report are updates on the form and contents of the Database, which stems from a fivestep process of data partnerships, data definition and transfer, data formatting and normalization, analysis, and reporting. Selected observations are also reported.
Peters, Valerie A.; Hill, Roger Ray; Stinebaugh, Jennifer A.; Veers, Paul S.
Wind shear for large wind turbine generators at selected tall tower sites
The objective of the study described in this report is to examine the nature of wind shear profiles and their variability over the height of large horizontal-axis wind turbines and to provide information on wind shear relevant to the design and opertion of large wind turbines. Wind turbine fatigue life and power quality are related through the forcing functions on the blade to the shapes of the wind shear profiles and their fluctuations over the disk of rotation.
Elliott, D.L.
NREL: Wind Research - Fabric-Covered Blades Could Make Wind Turbines...
Fabric-Covered Blades Could Make Wind Turbines Cheaper and More Efficient A photo of a crew of workers watching as a wind blade is hauled up to a turbine for assembly. A new...
Combined Experiment Phase 1. [Horizontal axis wind turbines: wind tunnel testing versus field testing
How does wind tunnel airfoil data differ from the airfoil performance on an operating horizontal axis wind turbine (HAWT) The National Renewable Energy laboratory has been conducting a comprehensive test program focused on answering this question and understanding the basic fluid mechanics of rotating HAWT stall aerodynamics. The basic approach was to instrument a wind rotor, using an airfoil that was well documented by wind tunnel tests, and measure operating pressure distributions on the rotating blade. Based an the integrated values of the pressure data, airfoil performance coefficients were obtained, and comparisons were made between the rotating data and the wind tunnel data. Care was taken to the aerodynamic and geometric differences between the rotating and the wind tunnel models. This is the first of two reports describing the Combined Experiment Program and its results. This Phase I report covers background information such as test setup and instrumentation. It also includes wind tunnel test results and roughness testing.
Butterfield, C.P.; Musial, W.P.; Simms, D.A.
Utility Scale Wind turbine Demonstration Project
The purpose of the Three Affiliated Tribes proposing to Department of Energy was nothing new to Denmark. National Meteorological Studies have proved that North Dakota has some of the most consistence wind resources in the world. The Three Affiliated Tribes wanted to assess their potential and become knowledgeable to developing this new and upcoming resource now valuable. By the Tribe implementing the Utility-scale Wind Turbine Project on Fort Berthold, the tribe has proven the ability to complete a project, and has already proceeded in a feasibility studies to developing a large-scale wind farm on the reservation due to tribal knowledge learned, public awareness, and growing support of a Nation wanting clean renewable energy. The tribe is working through the various measures and regulations with the want to be self-sufficient, independent, and marketable with 17,000 times the wind energy needed to service Fort Berthold alone.
Terry Fredericks
The Federal Advanced Wind Turbine Program
The development of technologically advanced, higher efficiency wind turbines has been identified as a high priority activity by the US wind industry. The Department of Energy's Wind Energy Program has begun a multi-year development program aimed at assisting the wind industry with the design, development, and testing of advanced wind turbine systems that can compete with conventional electric generation for $0.05/kWh at 13 mph sites by the mid-1990s and with fossil-fuel-based generators for $0.04/kWh at 13 mph sites by the year 2000. The development plan consists of four phases: (1) Conceptual Design Studies; (2) Near-Term Product Development; (3) Next Generation Technology Integration and Design, and (4) Next- Generation Technology Development and Testing. The Conceptual Design Studies were begun in late 1990, and are scheduled for completion in the Spring of 1992. Preliminary results from these analyses are very promising and indicate that the goals stated above are technically feasible. This paper includes a brief summary of the Conceptual Design Studies and presents initial plans for the follow-on activities. 3 refs., 4 figs.
Hock, S M; Thresher, R W [National Renewable Energy Lab., Golden, CO (United States); Goldman, P R [USDOE, Washington, DC (United States)
The development of technologically advanced, higher efficiency wind turbines has been identified as a high priority activity by the US wind industry. The Department of Energy`s Wind Energy Program has begun a multi-year development program aimed at assisting the wind industry with the design, development, and testing of advanced wind turbine systems that can compete with conventional electric generation for $0.05/kWh at 13 mph sites by the mid-1990s and with fossil-fuel-based generators for $0.04/kWh at 13 mph sites by the year 2000. The development plan consists of four phases: (1) Conceptual Design Studies; (2) Near-Term Product Development; (3) Next Generation Technology Integration and Design, and (4) Next- Generation Technology Development and Testing. The Conceptual Design Studies were begun in late 1990, and are scheduled for completion in the Spring of 1992. Preliminary results from these analyses are very promising and indicate that the goals stated above are technically feasible. This paper includes a brief summary of the Conceptual Design Studies and presents initial plans for the follow-on activities. 3 refs., 4 figs.
Hock, S.M.; Thresher, R.W. [National Renewable Energy Lab., Golden, CO (United States); Goldman, P.R. [USDOE, Washington, DC (United States)
A thick airfoil is described for the root region of the blade of a wind turbine. The airfoil has a thickness in a range from 24%--26% and a Reynolds number in a range from 1,000,000 to 1,800,000. The airfoil has a maximum lift coefficient of 1.4--1.6 that has minimum sensitivity to roughness effects. 3 Figs.
Mod 2 Wind Turbine Development Project
The primary objective in the development of Mod 2 was to design a wind turbine to produce energy for less than 5 cents/kWh based on 1980 cost forecasts. The pricing method used to project the Mod 2 energy costs is the levelized fixed charge rate approach, generally accepted in the electric utility industry as a basis for relative ranking of energy alternatives. This method derives a levelized energy price necessary to recover utility's purchasing, installing, owning, operating, and maintenance costs.
Extreme learning machine based wind speed estimation and sensorless control for wind turbine power generation system
This paper proposes a precise real-time wind speed estimation method and sensorless control for variable-speed variable-pitch wind turbine power generation system (WTPGS). The wind speed estimation is realized by a nonlinear input-output mapping extreme ... Keywords: Extreme learning machine, Sensorless control, Wind speed estimation, Wind turbine power generation system
Si Wu; Youyi Wang; Shijie Cheng
Feasibility Studies on Disturbance Feedforward Techniques to Improve Wind Turbine Load Mitigation Performance: January 2009 -- January 2010
This study investigates disturbance feedforward and preview control to better understand the best possible improvement in load mitigation using advanced wind measurement techniques.
Laks, J.H.; Dunne, F.; Pao, L. Y.
TurbSim: Reliability-based wind turbine simulator
Wind turbine farms are an effective generator of electricity in windy parts of the world, with prices progressing to levels competitive with other sources. Choosing the correct turbine for a given installation requires significant engineering and the ...
Joseph T. Foley; Timothy G. Gutowski
of wind turbine. Rating Control Rotor Radius Rated Windturbines is a major design consideration due to cyclic loading induced by the rotating rotors [the turbine. The base was assumed to be fixed and the rotor
Numerical simulation of tower rotor interaction for downwind wind turbine
Downwind wind turbines have lower upwind rotormisalignment, and thus lower turning moment and self-steered advantage over the upwind configuration. In this paper, numerical simulation to the downwind turbine is conducted to investigate the interaction ...
Isam Janajreh; Ilham Talab; Jill Macpherson
Electric Power Research Institute Utility Wind Turbine Verification Program
This report provides an overview of the DOE EPRI Wind Turbine Verification Program (TVP) and the Turbine Verification and Technology Transfer Projects funded by the program between 1994 and 2004.
Wind Turbine Pitch Angle Controllers for Grid Frequency Stabilisation
Wind Turbine Pitch Angle Controllers for Grid Frequency Stabilisation Clemens Jauch Risø National Laboratory Wind Energy Department P.O. Box 49 DK-4000 Roskilde, Denmark email@example.com Abstract: In this paper it is investigated how active-stall wind turbines can contribute to the stabilisation of the power
Lidar investigation of atmosphere effect on a wind turbine wake
An experimental study of the spatial wind structure in the vicinity of a wind turbine by a NOAA coherent Doppler lidar has been conducted. It has been found out that a working wind turbine generates a wake with the maximum velocity deficit varying ...
I. N. Smalikho; V. A. Banakh; Y. L. Pichugina; W. A. Brewer; R. M. Banta; J. K. Lundquist; N. D. Kelley
Lidar Investigation of Atmosphere Effect on a Wind Turbine Wake
An experimental study of the spatial wind structure in the vicinity of a wind turbine by a NOAA coherent Doppler lidar has been conducted. It was found that a working wind turbine generates a wake with the maximum velocity deficit varying from 27% ...
NREL Establishes a 1.5-MW Wind Turbine Test Platform for Research Partnerships (Fact Sheet)
Research turbine supports sustained technology development. For more than three decades, engineers at the National Renewable Energy Laboratory's (NREL) National Wind Technology Center (NWTC) have worked with the U.S. Department of Energy (DOE) Wind Program and industry partners to advance wind energy technology, improve wind turbine performance, and reduce the cost of energy. Although there have been dramatic increases in performance and drops in the cost of wind energy-from $0.80 per kilowatt-hour to between $0.06 and $0.08 per kilowatt-hour-the goal of the DOE Wind Program is to further increase performance and reduce the cost of energy for land-based systems so that wind energy can compete with natural gas by 2020. In support of the program's research and development (R and D) efforts, NREL has constructed state-of-the-art facilities at the NWTC where industry partners, universities, and other DOE laboratories can conduct tests and experiments to further advance wind technology. The latest facility to come online is the DOE-GE 1.5-MW wind turbine test platform. Working with DOE, NREL purchased and installed a GE 1.5-MW wind turbine at the NWTC in 2009. Since then, NREL engineers have extensively instrumented the machine, conducted power performance and full-system modal tests, and collected structural loads measurements to obtain baseline characterization of the turbine's power curve, vibration characteristics, and fatigue loads in the uniquely challenging NWTC inflow environment. By successfully completing a baseline for the turbine's performance and structural response, NREL engineers have established a test platform that can be used by industry, university, and DOE laboratory researchers to test wind turbine control systems and components. The new test platform will also enable researchers to acquire the measurements needed to develop and validate wind turbine models and improve design codes.
36 SEPTEMBER | 2012 WiNd TURbiNE CAPACiTY
36 SEPTEMBER | 2012 WiNd TURbiNE CAPACiTY FRONTiER FROM SCAdA ThE WORld hAS SEEN A significant contributor to this growth. The wind turbine generated energy depends on the wind potential and the turbine of wind turbines. Supervi- sory control and data acquisition (SCADA) systems record wind turbine
Innovative wind turbines. Circulation controlled vertical axis wind turbine. Progress report, March 1-December 31, 1976
Theoretical and experimental research efforts in evaluating an innovative concept for vertical axis wind turbines (VAWT) are described. The concept is that of using straight blades composed of circulation controlled airfoil sections. The theoretical analysis has been developed to determine the unsteady lift and moment characteristics of multiple-blade cross-flow wind turbines. To determine the drag data needed as input to the theoretical analysis, an outdoor test model VAWT has been constructed; design details, instrumentation, and calibration results are reported. Initial testing is with fixed pitch blades having cross-sections of conventional symmetrical airfoils. Costs of building the test model are included, as well as estimates for blades constructed with composite materials. These costs are compared with those of other types of wind turbines.
Walters, R. E.; Fanucci, J. B.; Hill, P. W.; Migliore, P. G.; Squire, W.; Waltz, T. L.
Turbine-Turbine Interaction and Performance Detailed (Fact Sheet), NREL Highlights, Science
Next-generation modeling capability assesses wind turbine array fluid dynamics and aero-elastic simulations.
Radar-cross-section reduction of wind turbines. part 1.
In recent years, increasing deployment of large wind-turbine farms has become an issue of growing concern for the radar community. The large radar cross section (RCS) presented by wind turbines interferes with radar operation, and the Doppler shift caused by blade rotation causes problems identifying and tracking moving targets. Each new wind-turbine farm installation must be carefully evaluated for potential disruption of radar operation for air defense, air traffic control, weather sensing, and other applications. Several approaches currently exist to minimize conflict between wind-turbine farms and radar installations, including procedural adjustments, radar upgrades, and proper choice of low-impact wind-farm sites, but each has problems with limited effectiveness or prohibitive cost. An alternative approach, heretofore not technically feasible, is to reduce the RCS of wind turbines to the extent that they can be installed near existing radar installations. This report summarizes efforts to reduce wind-turbine RCS, with a particular emphasis on the blades. The report begins with a survey of the wind-turbine RCS-reduction literature to establish a baseline for comparison. The following topics are then addressed: electromagnetic model development and validation, novel material development, integration into wind-turbine fabrication processes, integrated-absorber design, and wind-turbine RCS modeling. Related topics of interest, including alternative mitigation techniques (procedural, at-the-radar, etc.), an introduction to RCS and electromagnetic scattering, and RCS-reduction modeling techniques, can be found in a previous report.
Brock, Billy C.; Loui, Hung; McDonald, Jacob J.; Paquette, Joshua A.; Calkins, David A.; Miller, William K.; Allen, Steven E.; Clem, Paul Gilbert; Patitz, Ward E.
Superconductivity for Large Scale Wind Turbines
A conceptual design has been completed for a 10MW superconducting direct drive wind turbine generator employing low temperature superconductors for the field winding. Key technology building blocks from the GE Wind and GE Healthcare businesses have been transferred across to the design of this concept machine. Wherever possible, conventional technology and production techniques have been used in order to support the case for commercialization of such a machine. Appendices A and B provide further details of the layout of the machine and the complete specification table for the concept design. Phase 1 of the program has allowed us to understand the trade-offs between the various sub-systems of such a generator and its integration with a wind turbine. A Failure Modes and Effects Analysis (FMEA) and a Technology Readiness Level (TRL) analysis have been completed resulting in the identification of high risk components within the design. The design has been analyzed from a commercial and economic point of view and Cost of Energy (COE) calculations have been carried out with the potential to reduce COE by up to 18% when compared with a permanent magnet direct drive 5MW baseline machine, resulting in a potential COE of 0.075 $/kWh. Finally, a top-level commercialization plan has been proposed to enable this technology to be transitioned to full volume production. The main body of this report will present the design processes employed and the main findings and conclusions.
R. Fair; W. Stautner; M. Douglass; R. Rajput-Ghoshal; M. Moscinski; P. Riley; D. Wagner; J. Kim; S. Hou; F. Lopez; K. Haran; J. Bray; T. Laskaris; J. Rochford; R. Duckworth
Program on Technology Innovation: Materials Degradation in Wind Turbines
The materials used for the construction of wind turbine systems can affect the economics of these systems for a variety of reasons. For instance, improvements in such materials properties as strength, stiffness, and fatigue life can lead to more efficient and more reliable wind turbines and to reductions in operation and maintenance costs. This report provides a comprehensive summary of the state of knowledge of materials used in major wind turbine components for both land-based and offshore applications...
Wind Power Technology Status and Performance and Cost Estimates - 2009
This report provides an update on the status and cost of wind power technology based on the Wind Power Technology Status and Performance and Cost Estimates � 2008 (EPRI report 1015806). It addresses the status of wind turbine and related technology for both onshore and offshore applications and the performance and cost of onshore wind power plants.
The Inside of a Wind Turbine | Department of Energy
The Inside of a Wind Turbine The Inside of a Wind Turbine The Inside of a Wind Turbine 1 of 17 Tower: 2 of 17 Tower: Made from tubular steel (shown here), concrete, or steel lattice. Supports the structure of the turbine. Because wind speed increases with height, taller towers enable turbines to capture more energy and generate more electricity. Generator: 3 of 17 Generator: Produces 60-cycle AC electricity; it is usually an off-the-shelf induction generator. High-speed shaft: 4 of 17 High-speed shaft: Drives the generator. Nacelle: 5 of 17 Nacelle: Sits atop the tower and contains the gear box, low- and high-speed shafts, generator, controller, and brake. Some nacelles are large enough for a helicopter to land on. Wind vane: 6 of 17 Wind vane: Measures wind direction and communicates with the yaw drive to orient the
Low Wind Speed Technology Phase I: Prototype Multi-Megawatt Low Wind Speed Turbine; General Electric Wind Energy, LLC
This fact sheet describes a subcontract with GE Wind Energy to develop an advanced prototype turbine to significantly reduce energy costs (COE) in low wind speed environments.
Wind turbine ring/shroud drive system - Energy Innovation Portal
A wind turbine capable of driving multiple electric generators having a ring or shroud structure for reducing blade root bending moments, hub loads, blade fastener ...
3D Simulation of a 5MW Wind Turbine.
??In the present work, the influence of turbulence and gravity forces on the tower and the rotor of a 5MW onshore wind turbine has been� (more)
Namiranian, Abtin
NREL: News - New Wind Turbine Dynamometer Test Facility Dedicated...
913 New Wind Turbine Dynamometer Test Facility Dedicated at NREL November 19, 2013 Today, the Energy Department (DOE) and its National Renewable Energy Laboratory (NREL) dedicated...
Assessing the Impacts of Reduced Noise Operations of Wind Turbines...
LBNL-3562E Assessing the Impacts of Reduced Noise Operations of Wind Turbines on Neighbor Annoyance: A Preliminary Analysis in Vinalhaven, Maine Ben Hoen, Haftan Eckholdt, and Ryan...
DOE to Invest $6 Million in Midsize Wind Turbine Technology ...
DOE to Invest $6 Million in Midsize Wind Turbine Technology Development May 25, 2010. The U.S. Department of Energy (DOE) today announced the availability ...
Barr Engineering Statement of Methodology Rosemount Wind Turbine...
Barr Engineering Statement of Methodology Rosemount Wind Turbine Simulations by Truescape Visual Reality, DOEEA-1791 (May 2010) Barr Engineering Statement of Methodology Rosemount...
WINDTUR1. TXT Large Wind Turbine Machines for ...
... 4. Reducing the diameter of the tower to lessen its shadow effect on the wind striking the turbine. D Suggested design changesO ...
An introduction to the small wind turbine project
Small wind turbines are typically used for the remote or rural areas of the world including: a village in Chile; a cabin dweller in the U.S.; a farmer who wants to water his crop; or a utility company that wants to use distributed generation to help defer building new transmission lines and distribution facilities. Small wind turbines can be used for powering communities, businesses, homes, and miscellaneous equipment to support unattended operation. This paper covers the U.S. Department of Energy/National Renewable Energy Laboratory Small Wind Turbine project, its specifications, its applications, the subcontractors and their small wind turbines concepts. 4 refs., 4 figs.
Forsyth, T.L.
to the support platform is the �NREL offshore 5- MW baselineOffshore wind turbine classification [3]. .. 3 Figure 1.2: Alternative platform
Airfoil treatments for vertical axis wind turbines
Sandia National Laboratories (SNL) has taken three airfoil related approaches to decreasing the cost of energy of vertical axis wind turbine (VAWT) systems; airfoil sections designed specifically for VAWTs, vortex generators (VGs), and ''pumped spoiling.'' SNL's blade element airfoil section design effort has led to three promising natural laminar flow (NLF) sections. One section is presently being run on the SNL 17-m turbine. Increases in peak efficiency and more desirable dynamic stall regulation characteristics have been observed. Vane-type VGs were fitted on one DOE/Alcoa 100 kW VAWT. With approximately 12% of span having VGs, annual energy production increased by 5%. Pumped spoiling utilizes the centrifugal pumping capabilities of hollow blades. With the addition of small perforations in the surface of the blades and valves controlled by windspeed at the ends of each blade, lift spoiling jets may be generated inducing premature stall and permitting lower capacity, lower cost drivetrain components. SNL has demonstrated this concept on its 5-m turbine and has wind tunnel tested perforation geometries on one NLF section.
Klimas, P.C.
NREL: Awards and Honors - North Wind 100/20 Wind Turbine
North Wind 100/20 Wind Turbine North Wind 100/20 Wind Turbine Developers: Gerry Nix and Brian Smith, National Renewable Energy Laboratory; Johnathan Lynch, Clint Coleman, Garrett Bywaters, and Rob Roland, Norhtern Power Systems; Dr. David Bubenheim and Michael Flynn, NASA Ames Research Center; and John Rand, National Science Foundation. The North Wind 100/20 Wind Turbine is a state-of-the-art wind turbine that is ideal for extreme cold conditions perfect for remote locations that may be off-grid or local-grid. The numeric designations represent the North Wind's capacity, 100-kilowatts (which is enough energy for 25-50 homes), and 20-meter diameter blades. The size of the North Wind 100/20 is unique, fitting an important market niche between large and small turbines. Large turbines (400-kilowatts and
Documentation, User Support, and Verification of Wind Turbine and Plant Models
As part of the Utility Wind Energy Integration Group (UWIG) and EnerNex's Wind Turbine Modeling Project, EnerNex has received ARRA (federal stimulus) funding through the Department of Energy (DOE) to further the progress of wind turbine and wind plant models. Despite the large existing and planned wind generation deployment, industry-standard models for wind generation have not been formally adopted. Models commonly provided for interconnection studies are not adequate for use in general transmission planning studies, where public, non-proprietary, documented and validated models are needed. NERC MOD (North American Electric Reliability Corporation) reliability standards require that power flow and dynamics models be provided, in accordance with regional requirements and procedures. The goal of this project is to accelerate the appropriate use of generic wind turbine models for transmission network analysis by: (1) Defining proposed enhancements to the generic wind turbine model structures that would allow representation of more advanced; (2) Comparative testing of the generic models against more detailed (and sometimes proprietary) versions developed by turbine vendors; (3) Developing recommended parameters for the generic models to best mimic the performance of specific commercial wind turbines; (4) Documenting results of the comparative simulations in an application guide for users; (5) Conducting technology transfer activities in regional workshops for dissemination of knowledge and information gained, and to engage electric power and wind industry personnel in the project while underway; (6) Designing of a "living" homepage to establish an online resource for transmission planners.
Robert Zavadil; Vadim Zheglov; Yuriy Kazachkov; Bo Gong; Juan Sanchez; Jun Li
NREL's Gearbox Reliability Collaborative leads to wind turbine gearbox reliability, lowering the cost of energy.
NREL's Gearbox Reliability Collaborative leads to wind turbine gearbox reliability, lowering have been able to identify shortcomings in the design, testing, and operation of wind turbines findings are quickly shared among GRC participants, including many wind turbine manufacturers and equipment
Rotationally sampled wind characteristics and correlations with MOD-OA wind turbine response
This report presents results of a comprehensive wind and wind turbine measurement program: the Clayton, New Mexico, vertical plane array/MOD-OA project. In this experiment, the turbulent wind was measured for a large array of fixed anemometers located two blade diameters upwind of a 200-kW horizontal-axis wind turbine (HAWT). Simultaneously, key wind turbine response parameters were also measured. The first of two major objectives of this experiment was to determine the turbulent wind, rotationally sampled to emulate the motion of the wind turbine blade, for the range of different wind speeds and stability classes actually experienced by the wind turbine. The second major objective was to correlate this rotationally sampled wind with the wind turbine blade stress and power, in order to assess the usefulness of the wind measurements for wind turbine loads testing a prediction. Time series of rotationally sampled winds and wind turbine blade bending moments and power were converted to frequency spectra using Fourier transform techniques. These spectra were used as the basis for both qualitative and quantitative comparisons among the various cases. A quantitative comparison between the rotationally sampled wind input and blade bending response was made, using the Fourier spectra to estimate the blade transfer function. These transfer functions were then used to calculate an approximate damping coefficient for the MOD-OA fiberglass blade.
George, R.L.; Connell, J.R.
Processing of High Performance Alloys for A-USC Steam Turbine ...
Fracture Toughness Evaluation of Polymeric Materials for Wind Turbine Blades Using the Spiral Notch Torsion Test � High Performance Alloys for Advanced�...
NREL: Wind Research - White Earth Nation Installs Turbines: A...
White Earth Nation Installs Turbines: A Wind Powering America Success Story February 11, 2013 Almost 8 years after taking the initial steps to harness the wind, the White Earth...
Lessons Learned: Milwaukee�s Wind Turbine Project
U.S. Department of Energy Community and Renewable Energy Success Stories webinar series titled Wind Energy in Urban Environments. This presentation describes a mid-size wind turbine installation near downtown Milwaukee, Wisconsin.
Multi-piece wind turbine rotor blades and wind turbines incorporating same
A multisection blade for a wind turbine includes a hub extender having a pitch bearing at one end, a skirt or fairing having a hole therethrough and configured to mount over the hub extender, and an outboard section configured to couple to the pitch bearing.
Moroz; Emilian Mieczyslaw (San Diego, CA)
NREL Software Aids Offshore Wind Turbine Designs (Fact Sheet)
NREL researchers are supporting offshore wind power development with computer models that allow detailed analyses of both fixed and floating offshore wind turbines. While existing computer-aided engineering (CAE) models can simulate the conditions and stresses that a land-based wind turbine experiences over its lifetime, offshore turbines require the additional considerations of variations in water depth, soil type, and wind and wave severity, which also necessitate the use of a variety of support-structure types. NREL's core wind CAE tool, FAST, models the additional effects of incident waves, sea currents, and the foundation dynamics of the support structures.
Wind Turbine Drivetrain Condition Monitoring - An Overview (Presentation)
High operation and maintenance costs still hamper the development of the wind industry despite its quick growth worldwide. To reduce unscheduled downtime and avoid catastrophic failures of wind turbines and their components have been and will be crucial to further raise the competitiveness of wind power. Condition monitoring is one of the key tools for achieving such a goal. To enhance the research and development of advanced condition monitoring techniques dedicated to wind turbines, we present an overview of wind turbine condition monitoring, discuss current practices, point out existing challenges, and suggest possible solutions.
Sheng, S.; Yang, W.
Effects of turbulence on power generation for variable-speed wind turbines
One of the primary advantages of variable-speed wind turbines over fixed-speed turbines should be improved aerodynamic efficiency. With variable-speed generation, in order to maintain a constant ratio of wind speed to tip speed, the wind turbine changes rotor speed as the wind speed changes. In this paper we compare a stall-controlled, variable-speed wind turbine to a fixed-speed turbine. The focus of this paper is to investigate the effects of variable speed on energy capture and its ability to control peak power. We also show the impact of turbulence on energy capture in moderate winds. In this report, we use a dynamic simulator to apply different winds to a wind turbine model. This model incorporates typical inertial and aerodynamic performance characteristics. From this study we found a control strategy that makes it possible to operate a stall-controlled turbine using variable speed to optimize energy capture and to control peak power. We also found that turbulence does not have a significant impact on energy capture.
Muljadi, E.; Butterfield, C.P.; Buhl, M.L. Jr.
Recent results from data analysis of dynamic stall on wind turbine blades
Wind turbines are subjected to dynamic loading from a variety of different sources. Wind shear and turbulence cause time-varying inflow that results in unsteady airloads. Tower shadow, upwind turbine wakes, and yaw angles also introduce unsteady inflow to wind turbine rotors. Wind turbine designers must predict these loads accurately in order to adequately design blades, hubs, and the remaining support structure to achieve a 30-year life. Structural analysts have not been able to predict mean or dynamic loads accurately enough to predict the fatigue life of major wind turbine components with confidence. Part of the problem is due to uncertainty in the stochastic wind environments as mentioned earlier. Another important part of the problem is the lack of basic knowledge of rotary wing airfoil stall performance. There is mounting evidence that dynamic stall may be related to dynamic loads that are greater than predictions. This paper describes some results of investigations of unsteady aerodynamic loads measured on a wind turbine blade. The objective of the investigation is to understand the steady and unsteady stall behavior of wind turbine blades. 13 refs.
Butterfield, C.P.; Simms, D. [National Renewable Energy Lab., Golden, CO (United States); Huyer, S. [Colorado Univ., Boulder, CO (United States)
NREL: News Feature - Giant Wind Turbine Test Takes a Heavyweight
Giant Wind Turbine Test Takes a Heavyweight Giant Wind Turbine Test Takes a Heavyweight May 17, 2010 Photo of Samsung's 90-ton drive train connected to NREL's 2.5-megawatt dynamometer in a high-ceiling metal building. The drive train is a cylindrical shape, but several attachments give it the look of a giant Lego contraption. Enlarge image A coupling of giants: Samsung's 2.5-megawatt wind turbine drive train meets the National Wind Technology Center's 2.5-megawatt dynamometer. Samsung's drive train weighs 90 tons and is the brains behind its 2.5-megawatt wind turbine that can supply electricity to 1,800 homes. Credit: Rob Wallen In a coupling of giants recently, the 2.5-megawatt dynamometer at the U.S. Department of Energy's National Renewable Energy Laboratory blasted 12.6 million inch pounds of torque at Samsung's 185,000-pound wind turbine drive
Loads Analysis of a Floating Offshore Wind Turbine Using Fully Coupled Simulation: Preprint
This paper presents the use of fully coupled aero-hydro-servo-elastic simulation tools to perform a loads analysis of a 5-MW offshore wind turbine supported by a barge with moorings, one of many promising floating platform concepts.
Jonkman, J. M.; Buhl, M. L., Jr.
The Probability Distribution of Wind Power From a Dispersed Array of Wind Turbine Generators
A method is presented for estimating the probability distribution of wind power from a dispersed array of wind turbine sites where the correlation between wind speeds at distinct sites is less than unity. The distribution is obtained from a model ...
John Carlin; John Haslett
Dynamic simulation of dual-speed wind turbine generation
Induction generators have been used since the early development of utility-scale wind turbine generation. An induction generator is the generator of choice because of its ruggedness, and low cost. With an induction generator, the operating speed of the wind turbine is limited to a narrow range (almost constant speed). Dual- speed operation can be accomplished by using an induction generator with two different sets of winding configurations or by using two induction generators with two different rated speeds. With single- speed operation, the wind turbine operates at different power coefficients (Cp) as the wind speed varies. The operation at maximum Cp can occur only at a single wind speed. However, if the wind speed varies across a wider range, the operating Cp will vary significantly. Dual-speed operation has the advantage of enabling the wind turbine to operate at near maximum Cp over a wider range of wind-speeds. Thus, annual energy production can be increased. The dual-speed mode may generate less energy than a variable-speed mode; nevertheless, it offers an alternative to capture more energy than single-speed operation. In this paper, dual-speed operation of a wind turbine will be investigated. One type of control algorithm for dual- speed operation is proposed. Results from a dynamic simulation will be presented to show how the control algorithm works and how power, current and torque of the system vary as the wind turbine is exposed to varying wind speeds.
Muljadi, E.; Butterfield, C.P.
Gas Turbine World performance specs 1984
The following topics are discussed: working insights into the performance specifications; performance and design characteristics of electric power plants, mechanical drive gas turbines, and marine propulsion gas turbines; and performance calculations.
Overview: Zoning for Small Wind Turbines
Overview: Overview: Zoning for Small Wind Turbines Jim Green NREL ASES Small Wind Division Webinar January 17, 2008 2 Zoning Basics * Zoning is one form of land use law * Based on legal principle of "police power:" the power to regulate in order to promote the health, morals, safety, and general welfare of the community * Zoning authority originates from state laws called "zoning enabling legislation" - Standard Zoning Enabling Act, Dept. of Commerce, 1920s * Enabling legislation delegates land use authority to local jurisdictions, "Home Rule" - counties, parishes, boroughs, townships, municipalities, cities, villages, etc. 3 Zoning is Daunting * 3,034 counties (National Association of Counties) * 16,504 townships * 19,429 municipalities (National League of Cities)
Wind turbine generator with improved operating subassemblies
A wind turbine includes a yaw spring return assembly to return the nacelle from a position to which it has been rotated by yawing forces, thus preventing excessive twisting of the power cables and control cables. It also includes negative coning restrainers to limit the bending of the flexible arms of the rotor towards the tower, and stop means on the rotor shaft to orient the blades in a vertical position during periods when the unit is upwind when the wind commences. A pendulum pitch control mechanism is improved by orienting the pivot axis for the pendulum arm at an angle to the longitudinal axis of its support arm, and excessive creep is of the synthetic resin flexible beam support for the blades is prevented by a restraining cable which limits the extent of pivoting of the pendulum during normal operation but which will permit further pivoting under abnormal conditions to cause the rotor to stall.
Cheney, Jr., Marvin C. (24 Stonepost Rd., Glastonbury, CT 06033)
Passive load control for large wind turbines.
Wind energy research activities at Sandia National Laboratories focus on developing large rotors that are lighter and more cost-effective than those designed with current technologies. Because gravity scales as the cube of the blade length, gravity loads become a constraining design factor for very large blades. Efforts to passively reduce turbulent loading has shown significant potential to reduce blade weight and capture more energy. Research in passive load reduction for wind turbines began at Sandia in the late 1990's and has moved from analytical studies to blade applications. This paper discusses the test results of two Sandia prototype research blades that incorporate load reduction techniques. The TX-100 is a 9-m long blade that induces bend-twist coupling with the use of off-axis carbon in the skin. The STAR blade is a 27-m long blade that induces bend-twist coupling by sweeping the blade in a geometric fashion.
Ashwill, Thomas D.
(Construction of a wind turbine). Final report
A wind powered electrical generator was built by industrial arts students working in electricity, woodworking, and metal technology facilities. The blades were originally aluminum frames covered with sailcloth. These were replaced with hand-carved laminated basswood blades. Original plans called for a bullet and downwind propeller, but this was replaced with an upwind propeller and an aft-mounted tailfin. A V-belt and pulley drive transmits power from the turbine and a motorcycle brake stops the machine during high winds and/or for safe servicing. The original 13 volt, 105 amp alternator was replaced by a 12 volt, 100 amp dc generator. Publicity and dissemination events are listed as well as expenditures. (LEW)
Devine, L.E.
Wind Turbine Blade Flow Fields and Prospects for Active Aerodynamic Control: Preprint
This paper describes wind turbine flow fields that can cause adverse aerodynamic loading and can impact active aerodynamic control methodologies currently contemplated for wind turbine applications.
Schreck, S.; Robinson, M.
An investigation of design alternatives for 328-ft (100-m) tall wind turbine towers.
??As wind turbines are continued to be placed at higher elevations, the need for taller wind turbine towers becomes necessary. However, there are multiple challenges� (more)
Lewin, Thomas James
Impacts of Wind Turbine Development in U.S. Counties Title Economic Impacts of Wind Turbine Development in U.S. Counties Publication Type Presentation Year of Publication...
Development and Validation of WECC Variable Speed Wind Turbine Dynamic Models for Grid Integration Studies
This paper describes reduced-order, simplified wind turbine models for analyzing the stability impact of large arrays of wind turbines with a single point of network interconnection.
Behnke, M.; Ellis, A.; Kazachkov, Y.; McCoy, T.; Muljadi, E.; Price, W.; Sanchez-Gasca, J.
A. Zervos. 2011a. �Wind Energy. � In IPCC Special Report onconsequent impacts on wind turbine and wind energy pricing.References American Wind Energy Association (AWEA). 2011.
Combining Droop Curve Concepts with Control Systems for Wind Turbine Active Power Control: Preprint
Wind energy is becoming a larger portion of the global energy portfolio and wind penetration has increased dramatically in certain regions of the world. This increasing wind penetration has driven the need for wind turbines to provide active power control (APC) services to the local utility grid, as wind turbines do not intrinsically provide frequency regulation services that are common with traditional generators. It is common for large scale wind turbines to be decoupled from the utility grid via power electronics, which allows the turbine to synthesize APC commands via control of the generator torque and blade pitch commands. Consequently, the APC services provided by a wind turbine can be more flexible than those provided by conventional generators. This paper focuses on the development and implementation of both static and dynamic droop curves to measure grid frequency and output delta power reference signals to a novel power set point tracking control system. The combined droop curve and power tracking controller is simulated and comparisons are made between simulations using various droop curve parameters and stochastic wind conditions. The tradeoffs involved with aggressive response to frequency events are analyzed. At the turbine level, simulations are performed to analyze induced structural loads. At the grid level, simulations test a wind plant's response to a dip in grid frequency.
Buckspan, A.; Aho, J.; Pao, L.; Fleming, P.; Jeong, Y.
Control of Wind Turbines: Past, Present, and Future
We review the objectives and techniques used in the control of horizontal axis wind turbines at the individual turbine level, where controls are applied to the turbine blade pitch and generator. The turbine system is modeled as a flexible structure operating in the presence of turbulent wind disturbances. Some overview of the various stages of turbine operation and control strategies used to maximize energy capture in below rated wind speeds is given, but emphasis is on control to alleviate loads when the turbine is operating at maximum power. After reviewing basic turbine control objectives, we provide an overview of the common basic linear control approaches and then describe more advanced control architectures and why they may provide significant advantages.
Laks, J. H.; Pao, L. Y.; Wright, A. D.
Experimental and analytical research on the aerodynamics of wind driven turbines. Final report
This aerodynamic research program was aimed at providing a reliable, comprehensive data base on a series of wind turbine models covering a broad range of the prime aerodynamic and geometric variables. Such data obtained under controlled laboratory conditions on turbines designed by the same method, of the same size, and tested in the same wind tunnel had not been available in the literature. Moreover, this research program was further aimed at providing a basis for evaluating the adequacy of existing wind turbine aerodynamic design and performance methodology, for assessing the potential of recent advanced theories and for providing a basis for further method development and refinement.
Rohrbach, C.; Wainauski, H.; Worobel, R.
Barr Engineering Statement of Methodology Rosemount Wind Turbine
Barr Engineering Statement of Methodology Rosemount Wind Turbine Barr Engineering Statement of Methodology Rosemount Wind Turbine Simulations by Truescape Visual Reality, DOE/EA-1791 (May 2010) Barr Engineering Statement of Methodology Rosemount Wind Turbine Simulations by Truescape Visual Reality, DOE/EA-1791 (May 2010) Barr Engineering, Minneapolis engaged Truescape in May 2010 to: 1) Provide a series of TrueViewTM2 "human field of view" survey controlled photo simulations from pre-determined viewpoint locations to assist with the assessment of the potential visibility of a proposed turbine, and 2) Simulate two different height options for the turbine tower, being 80m vs. 100m. Barr Engineering Statement of Methodology Rosemount Wind Turbine Simulations by Truescape Visual Reality, DOE/EA-1791 (May 2010)
Optimization locations of wind turbines with the particle swarm optimization
In this paper, a new algorithm is presented for the locations of wind turbine in the distribution systems. Technical constraints such as feeder capacity limits, bus voltage, and load balance are considered. The Particle Swarm Optimization(PSO) is applied ... Keywords: distribution system, equivalent current injection, particle swarm optimization, wind turbine
Ming-Tang Tsai; Szu-Wzi Wu
Electromagnetic torque analysis of a DFIG for wind turbines
Electromagnetic torque of doubly fed induction generator (DFIG) is a consequence of the rotor and stator supply. The stator voltage has a fixed amount and frequency. The rotor voltage of the DFIG as a part of a wind turbine has a variable amount and ... Keywords: DFIG, electromagnetic torque, renewable energy, wind turbine
Jurica Smajo; Dinko Vukadinovic
Simulation of doubly-fed machine with improved wind turbine
Most of wind turbines use induction generators that are very reliable with low costs [2], but when it is straightly connected to the grid, maximum power is not accessible [1] and only a few change of speed between maximum speed and synchronous speed ... Keywords: doubly-fed machine, gearbox ratio, high speed shaft, low speed shaft, wind turbine
Hengameh Kojooyan Jafari
DOE/NREL Advanced Wind Turbine Development Program
The development of technologically advanced, high-efficiency wind turbines continues to be a high-priority activity of the US wind industry. The National Renewable Energy Laboratory (formerly the Solar Energy Research Institute), sponsored by the US Department of Energy (DOE), has initiated the Advanced Wind Turbine Program to assist the wind industry in the development of a new class of advanced wind turbines. The initial phase of the program focused on developing conceptual designs for near-term and advanced turbines. The goal of the second phase of this program is to use the experience gained over the last decade of turbine design and operation combined with the latest existing design tools to develop a turbine that will produce energy at $0.05 per kilowatt-hour (kWh) in a 5.8-m/s (13-mph) wind site. Three contracts have been awarded, and two more are under negotiation in the second phase. The third phase of the program will use new innovations and state-of-the-art wind turbine design technology to produce a turbine that will generate energy at $0.04/kWh in a 5.8-m/s wind site. Details of the third phase will be announced in early 1993.
Butterfield, C.P.; Smith, B.; Laxson, A.; Thresher, B. [National Renewable Energy Lab., Golden, CO (United States); Goldman, P. [USDOE Assistant Secretary for Conservation and Renewable Energy, Washington, DC (United States). Wind/Hydro/Ocean Technologies Div.
Optimal wind turbines placement within a distribution market environment
This paper proposes a hybrid optimization method for optimal allocation of wind turbines (WTs) that combines genetic algorithm (GA) and market-based optimal power flow (OPF). The method jointly maximizes net present value (NPV) related to WTs investment ... Keywords: Genetic algorithm, Net present value, Social welfare maximization, Wind turbines
Geev Mokryani, Pierluigi Siano
Regional Field Verification -- Case Study of Small Wind Turbines in the Pacific Northwest: Preprint
The U.S. Department of Energy/National Renewable Energy Laboratory's (DOE/NREL) Regional Field Verification (RFV) project supports industry needs for gaining initial field operation experience with small wind turbines and verify the performance, reliability, maintainability, and cost of small wind turbines in diverse applications. In addition, RFV aims to help expand opportunities for wind energy in new regions of the United States by tailoring projects to meet unique regional requirements and document and communicate the experience from these projects for the benefit of others in the wind power development community and rural utilities. Between August 2003 and August 2004, six turbines were installed at different host sites. At least one year of data has been collected from five of these sites. This paper describes DOE/NREL's RFV project, reviews some of the lessons learned with regards to small wind turbine installations, summarizes operations data from these sites, and provides preliminary BOS costs.
Development of Fully Coupled Aeroelastic and Hydrodynamic Models for Offshore Wind Turbines: Preprint
Aeroelastic simulation tools are routinely used to design and analyze onshore wind turbines, in order to obtain cost effective machines that achieve favorable performance while maintaining structural integrity. These tools employ sophisticated models of wind-inflow; aerodynamic, gravitational, and inertial loading of the rotor, nacelle, and tower; elastic effects within and between components; and mechanical actuation and electrical responses of the generator and of control and protection systems. For offshore wind turbines, additional models of the hydrodynamic loading in regular and irregular seas, the dynamic coupling between the support platform motions and wind turbine motions, and the dynamic characterization of mooring systems for compliant floating platforms are also important. Hydrodynamic loading includes contributions from hydrostatics, wave radiation, and wave scattering, including free surface memory effects. The integration of all of these models into comprehensive simulation tools, capable of modeling the fully coupled aeroelastic and hydrodynamic responses of floating offshore wind turbines, is presented.
Jonkman, J. M.; Sclavounos, P. D.
Time-domain Fatigue Response and Reliability Analysis of Offshore Wind Turbines with
-domain based simulation model of 750 kW land-based wind turbine Gear contact fatigue analysis of a wind of 750 kW land-based wind turbine Gear contact fatigue analysis of a wind turbine drive train under response and reliability analysis #12;Time domain based simulation model of 750 kW land-based wind turbine
Nørvåg, Kjetil
M. Bahrami ENSC 283 (S 11) Wind Turbine Project 1 ENSC 283 Project
M. Bahrami ENSC 283 (S 11) Wind Turbine Project 1 ENSC 283 Project Assigned date: Feb. 23, 2011 family), but also important are those which extract energy form the fluid such as turbines. Wind turbines understanding of wind energy. Figure 1: Typical wind turbines Devices to harvest wind energy are available
Bahrami, Majid
innovati nNREL Innovations Contribute to an Award-Winning Small Wind Turbine
innovati nNREL Innovations Contribute to an Award-Winning Small Wind Turbine The Skystream 3.7 wind (NREL) and Southwest Windpower, a commercially successful small wind turbine manufacturer. NREL drew blade design that makes the wind turbine more efficient and quieter than most. Small wind turbines
Danehy Park Wind Turbine Project Preliminary Assessment Report
) Northern Power 100 (100 kW) Aeronautica 29-225 (225 kW) Polaris 500 (500 kW) The first four turbinesDanehy Park Wind Turbine Project Preliminary Assessment Report Danehy Park Project Group Wind the following five turbines for potential installation at Danehy Park: SkyStream 3.7 (2.4 kW) Polaris 20 (20 kW
Low Speed Technology for Small Turbine Development Reaction Injection Molded 7.5 Meter Wind Turbine Blade
International Turbine Research Wind Farm | Open Energy Information
Turbine Research Wind Farm Turbine Research Wind Farm Jump to: navigation, search Name International Turbine Research Wind Farm Facility International Turbine Research Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Developer International Turbine Research Energy Purchaser Pacific Gas & Electric Co Location Pacheco Pass CA Coordinates 37.0445°, -121.175° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":37.0445,"lon":-121.175,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Mid-Size Wind Turbines | Open Energy Information
Page Page Edit History Facebook icon Twitter icon » Mid-Size Wind Turbines Jump to: navigation, search A Vergnet GEV MP C 275-kW turbine at the Sandywoods Community, Rhode island. Photo from Stefan Dominioni/Vergnet S.A., NREL 26490. The U.S. Department of Energy defines mid-size wind turbines as 101 kilowatts to 1 megawatt.[1] Resources Kwartin, R.; Wolfrum, A.; Granfield, K.; Kagel, A.; Appleton, A. (2008). An Analysis of the Technical and Economic Potential for Mid-Scale Distributed Wind. National Renewable Energy Laboratory. Accessed September 27, 2013. National Renewable Energy Laboratory. Midsize Wind Turbine Research. Accessed September 27, 2013. This webpage discusses efforts to develop and commercialize mid-size wind turbines in the United States. References
Safety and Function Test Report for the Viryd CS8 Wind Turbine
This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. Several turbines were selected for testing at the National Wind Technology Center (NWTC) at the National Renewable Energy Laboratory (NREL) as a part of the Small Wind Turbine Independent Testing project. Safety and function testing is one of up to five tests that may be performed on the turbines. Other tests include duration, power performance, acoustic noise, and power quality. Viryd Technologies, Inc. of Austin, Texas, was the recipient of the DOE grant and provided the turbine for testing.
NREL: Wind Research - Entegrity Wind Systems's EW50 Turbine Testing and
Entegrity Wind Systems's EW50 Turbine Testing and Results Entegrity Wind Systems's EW50 Turbine Testing and Results Entegrity Wind Systems' EW50 wind turbine. Text Version As part of the National Renewable Energy Laboratory and U.S. Department of Energy (NREL/DOE) Independent Testing project, NREL tested Entegrity Wind Systems' EW50 turbine at the National Wind Technology Center (NWTC). The EW50 is a 50-kilowatt (kW), three-bladed, horizontal-axis downwind small wind turbine. The turbine's rotor diameter is 15 meters, and its hub height is 30.5 meters. It has a three-phase induction generator that operates at 480 volts AC. Testing Summary The summary of the tests is listed below, along with the final reports. Cumulative Energy Production 3/11/2009: 17; 3/12/2009: 17; 3/13/2009: 17; 3/14/2009: 17; 3/15/2009: 17;
Recovery Act: Online Nonintrusive Condition Monitoring and Fault Detection for Wind Turbines
The penetration of wind power has increased greatly over the last decade in the United States and across the world. The U.S. wind power industry installed 1,118 MW of new capacity in the first quarter of 2011 alone and entered the second quarter with another 5,600 MW under construction. By 2030, wind energy is expected to provide 20% of the U.S. electricity needs. As the number of wind turbines continues to grow, the need for effective condition monitoring and fault detection (CMFD) systems becomes increasingly important [3]. Online CMFD is an effective means of not only improving the reliability, capacity factor, and lifetime, but it also reduces the downtime, energy loss, and operation and maintenance (O&M) of wind turbines. The goal of this project is to develop novel online nonintrusive CMFD technologies for wind turbines. The proposed technologies use only the current measurements that have been used by the control and protection system of a wind turbine generator (WTG); no additional sensors or data acquisition devices are needed. Current signals are reliable and easily accessible from the ground without intruding on the wind turbine generators (WTGs) that are situated on high towers and installed in remote areas. Therefore, current-based CMFD techniques have great economic benefits and the potential to be adopted by the wind energy industry. Specifically, the following objectives and results have been achieved in this project: (1) Analyzed the effects of faults in a WTG on the generator currents of the WTG operating at variable rotating speed conditions from the perspective of amplitude and frequency modulations of the current measurements; (2) Developed effective amplitude and frequency demodulation methods for appropriate signal conditioning of the current measurements to improve the accuracy and reliability of wind turbine CMFD; (3) Developed a 1P-invariant power spectrum density (PSD) method for effective signature extraction of wind turbine faults with characteristic frequencies in the current or current demodulated signals, where 1P stands for the shaft rotating frequency of a WTG; (4) Developed a wavelet filter for effective signature extraction of wind turbine faults without characteristic frequencies in the current or current demodulated signals; (5) Developed an effective adaptive noise cancellation method as an alternative to the wavelet filter method for signature extraction of wind turbine faults without characteristic frequencies in the current or current demodulated signals; (6) Developed a statistical analysis-based impulse detection method for effective fault signature extraction and evaluation of WTGs based on the 1P-invariant PSD of the current or current demodulated signals; (7) Validated the proposed current-based wind turbine CMFD technologies through extensive computer simulations and experiments for small direct-drive WTGs without gearboxes; and (8) Showed, through extensive experiments for small direct-drive WTGs, that the performance of the proposed current-based wind turbine CMFD technologies is comparable to traditional vibration-based methods. The proposed technologies have been successfully applied for detection of major failures in blades, shafts, bearings, and generators of small direct-drive WTGs. The proposed technologies can be easily integrated into existing wind turbine control, protection, and monitoring systems and can be implemented remotely from the wind turbines being monitored. The proposed technologies provide an alternative to vibration-sensor-based CMFD. This will reduce the cost and hardware complexity of wind turbine CMFD systems. The proposed technologies can also be combined with vibration-sensor-based methods to improve the accuracy and reliability of wind turbine CMFD systems. When there are problems with sensors, the proposed technologies will ensure proper CMFD for the wind turbines, including their sensing systems. In conclusion, the proposed technologies offer an effective means to achieve condition-based smart maintenance for wind turbines and have a gre
Wei Qiao
Final Technical Report Recovery Act: Online Nonintrusive Condition Monitoring and Fault Detection for Wind Turbines
Testing and Modeling of a 3-MW Wind Turbine Using Fully Coupled Simulation Codes (Poster)
This poster describes the NREL/Alstom Wind testing and model verification of the Alstom 3-MW wind turbine located at NREL's National Wind Technology Center. NREL,in collaboration with ALSTOM Wind, is studying a 3-MW wind turbine installed at the National Wind Technology Center(NWTC). The project analyzes the turbine design using a state-of-the-art simulation code validated with detailed test data. This poster describes the testing and the model validation effort, and provides conclusions about the performance of the unique drive train configuration used in this wind turbine. The 3-MW machine has been operating at the NWTC since March 2011, and drive train measurements will be collected through the spring of 2012. The NWTC testing site has particularly turbulent wind patterns that allow for the measurement of large transient loads and the resulting turbine response. This poster describes the 3-MW turbine test project, the instrumentation installed, and the load cases captured. The design of a reliable wind turbine drive train increasingly relies on the use of advanced simulation to predict structural responses in a varying wind field. This poster presents a fully coupled, aero-elastic and dynamic model of the wind turbine. It also shows the methodology used to validate the model, including the use of measured tower modes, model-to-model comparisons of the power curve, and mainshaft bending predictions for various load cases. The drivetrain is designed to only transmit torque to the gearbox, eliminating non-torque moments that are known to cause gear misalignment. Preliminary results show that the drivetrain is able to divert bending loads in extreme loading cases, and that a significantly smaller bending moment is induced on the mainshaft compared to a three-point mounting design.
LaCava, W.; Guo, Y.; Van Dam, J.; Bergua, R.; Casanovas, C.; Cugat, C.
ERCOT's Dynamic Model of Wind Turbine Generators: Preprint
By the end of 2003, the total installed wind farm capacity in the Electric Reliability Council of Texas (ERCOT) system was approximately 1 gigawatt (GW) and the total in the United States was about 5 GW. As the number of wind turbines installed throughout the United States increases, there is a greater need for dynamic wind turbine generator models that can properly model entire power systems for different types of analysis. This paper describes the ERCOT dynamic models and simulations of a simple network with different types of wind turbine models currently available.
Muljadi, E.; Butterfield, C. P.; Conto, J.; Donoho, K.
Axial flux, modular, permanent-magnet generator with a toroidal winding for wind turbine applications
Permanent-magnet generators have been used for wind turbines for many years. Many small wind turbine manufacturers use direct-drive permanent-magnet generators. For wind turbine generators, the design philosophy must cover the following characteristics: low cost, light weight, low speed, high torque, and variable speed generation. The generator is easy to manufacture and the design can be scaled up for a larger size without major retooling. A modular permanent-magnet generator with axial flux direction was chosen. The permanent magnet used is NdFeB or ferrite magnet with flux guide to focus flux density in the air gap. Each unit module of the generator may consist of one, two, or more phases. Each generator can be expanded to two or more unit modules. Each unit module is built from simple modular poles. The stator winding is formed like a torus. Thus, the assembly process is simplified and the winding insertion in the slot is less tedious. The authors built a prototype of one unit module and performed preliminary tests in the laboratory. Follow up tests will be conducted in the lab to improve the design.
Muljadi, E.; Butterfield, C.P.; Wan, Y.H.
In-field use of laser Doppler vibrometer on a wind turbine blade
One of our primary goals was to determine how well a laser Doppler vibrometer (LDV) could measure the structural dynamic response of a wind turbine that was parked in the field. We performed a series of preliminary tests in the lab to determine the basic limitations of the LDV for this application. We then instrumented an installed parked horizontal axis wind turbine with accelerometers to determine the natural frequencies, damping, and mode shapes of the wind turbine and rotor as a baseline for the LDV and our other tests. We also wanted to determine if LDV modal information could be obtained from a naturally (wind) excited wind turbine. We compared concurrently obtained accelerometer and LDV data in an attempt to assess the quality of the LDV data. Our test results indicate the LDV can be successfully used in the field environment of an installed wind turbine, but with a few restrictions. We were successful in obtaining modal information from a naturally (wind) excited wind turbine in the field, but the data analysis requires a large number of averaged data sets to obtain reasonable results. An ultimate goal of this continuing project is to develop a technique that will monitor the health of a structure, detect damage, and hopefully predict an impending component failure.
Rumsey, M.; Hurtado, J.; Hansche, B. [and others
City of Medford Wind Turbine | Open Energy Information
Medford Wind Turbine Medford Wind Turbine Jump to: navigation, search Name City of Medford Wind Turbine Facility City of Medford Wind Turbine Sector Wind energy Facility Type Small Scale Wind Facility Status In Service Owner City of Medford Developer Sustainable Energy Developments Energy Purchaser City of Medford Location Medford MA Coordinates 42.415768°, -71.107337° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.415768,"lon":-71.107337,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Three D Metals Wind Turbine | Open Energy Information
Three D Metals Wind Turbine Three D Metals Wind Turbine Jump to: navigation, search Name Three D Metals Wind Turbine Facility Three D Metals Wind Turbine Sector Wind energy Facility Type Small Scale Wind Facility Status In Service Owner Three D Metals Energy Purchaser Three D Metals Location Valley City OH Coordinates 41.248155°, -81.883079° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":41.248155,"lon":-81.883079,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Wind turbine reliability : a database and analysis approach.
The US wind Industry has experienced remarkable growth since the turn of the century. At the same time, the physical size and electrical generation capabilities of wind turbines has also experienced remarkable growth. As the market continues to expand, and as wind generation continues to gain a significant share of the generation portfolio, the reliability of wind turbine technology becomes increasingly important. This report addresses how operations and maintenance costs are related to unreliability - that is the failures experienced by systems and components. Reliability tools are demonstrated, data needed to understand and catalog failure events is described, and practical wind turbine reliability models are illustrated, including preliminary results. This report also presents a continuing process of how to proceed with controlling industry requirements, needs, and expectations related to Reliability, Availability, Maintainability, and Safety. A simply stated goal of this process is to better understand and to improve the operable reliability of wind turbine installations.
Linsday, James (ARES Corporation); Briand, Daniel; Hill, Roger Ray; Stinebaugh, Jennifer A.; Benjamin, Allan S. (ARES Corporation)
NREL: News Feature - New Test Facility to Improve Wind Turbines
Test Facility to Improve Wind Turbines Test Facility to Improve Wind Turbines December 26, 2013 Two men stand in front of the test equipment in the dynamometer facility discussing work being done. Behind them are two large blue machines that make up the dynamometer test apparatus. A white wind turbine nacelle system is attached to these devices to their left. Enlarge image NREL engineer Scott Lambert (left) and Project Manager Mark McDade discuss calibrations being done on the new dynamometer at the 5-MW Dynamometer Test Facility at NREL's National Wind Technology Center (NWTC). Credit: Dennis Schroeder Premature failures of mechanical systems have a significant impact on the cost of wind turbine operations and thus the total cost of wind energy. Recently, the Energy Department's National Renewable Energy Laboratory
Xi an Nordex Wind Turbine Co Ltd aka Xi an Weide Wind Power Equipment Co
Xi an Nordex Wind Turbine Co Ltd aka Xi an Weide Wind Power Equipment Co Xi an Nordex Wind Turbine Co Ltd aka Xi an Weide Wind Power Equipment Co Ltd Jump to: navigation, search Name Xi'an Nordex Wind Turbine Co Ltd (aka Xi'an Weide Wind Power Equipment Co Ltd) Place Xi An, Shaanxi Province, China Zip 710021 Sector Wind energy Product Subsidiary of Xiâ€(tm)an Aero-Engine that manufactures its 600kW wind turbines in Xi An, China. References Xi'an Nordex Wind Turbine Co Ltd (aka Xi'an Weide Wind Power Equipment Co Ltd)[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Xi'an Nordex Wind Turbine Co Ltd (aka Xi'an Weide Wind Power Equipment Co Ltd) is a company located in Xi An, Shaanxi Province, China . References ↑ "[ Xi'an Nordex Wind Turbine Co Ltd (aka Xi'an Weide Wind
Identification of Wind Turbine Response to Turbulent Inflow Structures: Preprint
The National Renewable Energy Laboratory conducted an experiment to obtain detailed wind measurements and corresponding wind turbine measurements in order to establish a causal relationship between coherent turbulent structures and wind turbine blade fatigue loads. Data were collected for one entire wind season from October 2000 to May 2001. During this period, the wind turbine operated under atmospheric conditions that support the formation of coherent turbulent structures 31% of the time. Using the equivalent fatigue load parameter as a measure of wind turbine blade fatigue and using statistical measures of the turbulent fluctuations of the wind, general correlation between the turbulence and the wind turbine response is shown. Direct correlation cannot be resolved with 10-minute statistics for several reasons. Multiple turbulent structures can exist within a 10-minute record, and the equivalent fatigue load parameter is essentially a 10-minute statistic that cannot estimate turbine response to individual turbulent structures. Large-magnitude turbulent fluctuations in the form of instantaneous Reynolds stresses do not necessarily correspond directly to large-magnitude blade root moment amplitudes. Thus, additional work must be done to quantify the negative turbine response and to correlate this response to turbulent inflow parameters over time scales less than 10 minutes.
Hand, M. M.; Kelley, N. D.; Balas, M. J.
The objective of the program was to demonstrate and verify Certification-by-Analysis (CBA) capability for wind turbine blades made from advanced lightweight composite materials. The approach integrated durability and damage tolerance analysis with robust design and virtual testing capabilities to deliver superior, durable, low weight, low cost, long life, and reliable wind blade design. The GENOA durability and life prediction software suite was be used as the primary simulation tool. First, a micromechanics-based computational approach was used to assess the durability of composite laminates with ply drop features commonly used in wind turbine applications. Ply drops occur in composite joints and closures of wind turbine blades to reduce skin thicknesses along the blade span. They increase localized stress concentration, which may cause premature delamination failure in composite and reduced fatigue service life. Durability and damage tolerance (D&DT) were evaluated utilizing a multi-scale micro-macro progressive failure analysis (PFA) technique. PFA is finite element based and is capable of detecting all stages of material damage including initiation and propagation of delamination. It assesses multiple failure criteria and includes the effects of manufacturing anomalies (i.e., void, fiber waviness). Two different approaches have been used within PFA. The first approach is Virtual Crack Closure Technique (VCCT) PFA while the second one is strength-based. Constituent stiffness and strength properties for glass and carbon based material systems were reverse engineered for use in D&DT evaluation of coupons with ply drops under static loading. Lamina and laminate properties calculated using manufacturing and composite architecture details matched closely published test data. Similarly, resin properties were determined for fatigue life calculation. The simulation not only reproduced static strength and fatigue life as observed in the test, it also showed composite damage and fracture modes that resemble those reported in the tests. The results show that computational simulation can be relied on to enhance the design of tapered composite structures such as the ones used in turbine wind blades. A computational simulation for durability, damage tolerance (D&DT) and reliability of composite wind turbine blade structures in presence of uncertainties in material properties was performed. A composite turbine blade was first assessed with finite element based multi-scale progressive failure analysis to determine failure modes and locations as well as the fracture load. D&DT analyses were then validated with static test performed at Sandia National Laboratories. The work was followed by detailed weight analysis to identify contribution of various materials to the overall weight of the blade. The methodology ensured that certain types of failure modes, such as delamination progression, are contained to reduce risk to the structure. Probabilistic analysis indicated that composite shear strength has a great influence on the blade ultimate load under static loading. Weight was reduced by 12% with robust design without loss in reliability or D&DT. Structural benefits obtained with the use of enhanced matrix properties through nanoparticles infusion were also assessed. Thin unidirectional fiberglass layers enriched with silica nanoparticles were applied to the outer surfaces of a wind blade to improve its overall structural performance and durability. The wind blade was a 9-meter prototype structure manufactured and tested subject to three saddle static loading at Sandia National Laboratory (SNL). The blade manufacturing did not include the use of any nano-material. With silica nanoparticles in glass composite applied to the exterior surfaces of the blade, the durability and damage tolerance (D&DT) results from multi-scale PFA showed an increase in ultimate load of the blade by 9.2% as compared to baseline structural performance (without nano). The use of nanoparticles lead to a delay in the onset of delamination. Load-displacement relati
Galib Abumeri; Frank Abdi (PhD)
Numerical Study of the Effects of Atmospheric and Wake Turbulence on Wind Turbine Dynamics
Although the atmospheric sciences community has been studying the effects of atmospheric stability and surface roughness on the planetary boundary layer for some time, their effects on wind turbine dynamics have not been well studied. In this study, we performed numerical experiments to explore some of the effects of atmospheric stability and surface roughness on wind turbine dynamics. We used large-eddy simulation to create atmospheric winds and compute the wind turbine flows, and we modeled the wind turbines as revolving and flexible actuator lines coupled to a wind turbine structural and system dynamic model. We examined the structural moments about the wind turbine blade, low-speed shaft, and nacelle; power production; and wake evolution when large 5-MW turbines are subjected to winds generated from low- and high-surface roughness levels representative of offshore and onshore conditions, respectively, and also neutral and unstable atmospheric conditions. In addition, we placed a second turbine 7 rotor diameters downwind of the first one so that we could explore wake effects under these different conditions. The results show that the turbulent structures generated within the atmospheric boundary layer wind simulations cause isolated loading events at least as significant as when a turbine is waked by an upwind turbine. The root-mean-square (RMS) turbine loads are consistently larger when the surface roughness is higher. The RMS blade-root out-of-plane bending moment and low-speed shaft torque are higher when the atmospheric boundary layer is unstable as compared with when it is neutral. However, the RMS yaw moments are either equal or reduced in the unstable case as compared with the neutral case. For a given surface roughness, the ratio of power produced by the downwind turbine relative to that of the upwind turbine is 15-20% higher when the conditions are unstable as compared with neutral. For a given atmospheric stability, this power ratio is 10% higher with the onshore roughness value versus the offshore one. The main conclusion is that various coherent turbulent structures that form under different levels of atmospheric stability and surface roughness have important effects on wind turbine structural response, power production, and wake evolution.
Churchfield, M. J.; Lee, S.; Michalakes, J.; Moriarty, P. J.
Systematic Controller Design Methodology for Variable-Speed Wind Turbines
Variable-speed, horizontal axis wind turbines use blade-pitch control to meet specified objectives for three operational regions. This paper provides a guide for controller design for the constant power production regime. A simple, rigid, non-linear turbine model was used to systematically perform trade-off studies between two performance metrics. Minimization of both the deviation of the rotor speed from the desired speed and the motion of the actuator is desired. The robust nature of the proportional-integral-derivative controller is illustrated, and optimal operating conditions are determined. Because numerous simulation runs may be completed in a short time, the relationship between the two opposing metrics is easily visualized.
Hand, M. M.; Balas, M. J.
Wind Turbine Design Guideline DG03: Yaw and Pitch Rolling Bearing Life
This report describes the design criteria, calculation methods, and applicable standards recommended for use in performance and life analyses of ball and roller (rolling) bearings for yaw and pitch motion support in wind turbine applications. The formulae presented here for rolling bearing analytical methods and bearing-life ratings are consistent with methods in current use by wind turbine designers and rolling-bearing manufacturers.
Harris, T.; Rumbarger, J. H.; Butterfield, C. P.
A simple method of estimating wind turbine blade fatigue at potential wind turbine sites
This paper presents a technique of estimating blade fatigue damage at potential wind turbine sites. The cornerstone of this technique is a simple model for the blade`s root flap bending moment. The model requires as input a simple set of wind measurements which may be obtained as part of a routine site characterization study. By using the model to simulate a time series of the root flap bending moment, fatigue damage rates may be estimated. The technique is evaluated by comparing these estimates with damage estimates derived from actual bending moment data; the agreement between the two is quite good. The simple connection between wind measurements and fatigue provided by the model now allows one to readily discriminate between damaging and more benign wind environments.
Barnard, J.C.; Wendell, L.L.
Understanding Trends in Wind Turbine Prices Over the Past Decade Understanding Trends in Wind Turbine Prices Over the Past Decade Title Understanding Trends in Wind Turbine Prices Over the Past Decade Publication Type Report Refereed Designation Unknown Year of Publication 2011 Authors Bolinger, Mark, and Ryan H. Wiser Pagination 46 Date Published 10/2011 Publisher LBNL City Berkeley Keywords electricity markets and policy group, energy analysis and environmental impacts department Abstract Berkeley Lab has gathered price data on 81 U.S. wind turbine transactions totaling 23,850 MW announced from 1997 through early 2011. Figure ES-1 depicts these reported wind turbine transaction prices (along with the associated trend line), broken out by the size of the transaction (in MW). Figure ES-1 also presents average (global) turbine prices reported by Vestas for the years 2005 through 2010, as well as a range of reported pricing (among various turbine manufacturers) for transactions signed in 2010 and so far in 2011 (with 2011 prices generally lower than 2010 prices). After hitting a low of roughly $750/kW from 2000 to 2002, average wind turbine prices doubled through 2008, rising to an average of roughly $1,500/kW. Wind turbine prices have since declined substantially, with price quotes for transactions executed in 2010 and to date in 2011 ranging from $900-$1,400/kW depending on the manufacturer and turbine model. For example, turbines designed for lower wind speed sites - deploying higher hub heights and larger rotor diameters for a given nameplate capacity - are priced at the higher end of this range. These quotes suggest price declines of as much as 33% or more since late 2008, with an average decline closer to perhaps 20% for orders announced in 2010 (as opposed to in 2011, which has seen further price declines). These two substantial and opposing wind turbine price trends over the past decade - and particularly the doubling in prices in the 2002-2008 period - run counter to the smooth, gradually declining technology cost trajectories that are often assumed by energy analysts modeling the diffusion of new technologies, including wind power. Understanding and explaining this notable discrepancy between theory and historical reality is the primary motivation for this work. Taking a bottom-up approach, this report examines seven primary drivers of wind turbine prices in the United States, with the goal of estimating the degree to which each contributed to the doubling in turbine prices from 2002 through 2008, as well as the subsequent decline in prices through 2010 (our analysis does not extend into 2011 because several of these drivers are best gauged on a full-year basis due to seasonality issues).
The Wind Turbine Drivetrain Test Facility (WTDTF) is a state-of-the-art industrial facility used for testing wind turbine drivetrains and generators. Large power output wind turbines are primarily installed for off-shore wind power generation. The facility includes two test bays: one to accommodate turbine nacelles up to 7.5 MW and one for nacelles up to 15 MW. For each test bay, an independent data acquisition system (DAS) records signals from various sensors required for turbine testing. These signals include resistance temperature devices, current and voltage sensors, bridge/strain gauge transducers, charge amplifiers, and accelerometers. Each WTDTF DAS also interfaces with the drivetrain load applicator control system, electrical grid monitoring system and vibration analysis system.
Mcintosh, J.
3) Turbine manufacturer profitability, which can impact turbine prices independently of costs; and 4) Turbine design, which for the purpose of this analysis is principally manifested through increased turbine size. The other three drivers analyzed in this study can be considered exogenous influences, in that they can impact wind turbine costs but fall mostly outside of the direct control of the wind industry. These exogenous drivers include changes in: 5) Raw materials prices, which affect the cost of inputs to the manufacturing process; 6) Energy prices, which impact the cost of manufacturing and transporting turbines; and 7) Foreign exchange rates, which can impact the dollar amount paid for turbines and components imported into the United States.
Effect of Second-Order Hydrodynamics on Floating Offshore Wind Turbines: Preprint
Offshore winds are generally stronger and more consistent than winds on land, making the offshore environment attractive for wind energy development. A large part of the offshore wind resource is however located in deep water, where floating turbines are the only economical way of harvesting the energy. The design of offshore floating wind turbines relies on the use of modeling tools that can simulate the entire coupled system behavior. At present, most of these tools include only first-order hydrodynamic theory. However, observations of supposed second-order hydrodynamic responses in wave-tank tests performed by the DeepCwind consortium suggest that second-order effects might be critical. In this paper, the methodology used by the oil and gas industry has been modified to apply to the analysis of floating wind turbines, and is used to assess the effect of second-order hydrodynamics on floating offshore wind turbines. The method relies on combined use of the frequency-domain tool WAMIT and the time-domain tool FAST. The proposed assessment method has been applied to two different floating wind concepts, a spar and a tension-leg-platform (TLP), both supporting the NREL 5-MW baseline wind turbine. Results showing the hydrodynamic forces and motion response for these systems are presented and analysed, and compared to aerodynamic effects.
Roald, L.; Jonkman, J.; Robertson, A,; Chokani, N.
Analysis of Temporal and Spatial Characteristics on Output of Wind Farms with Doubly Fed Induction Generator Wind Turbines
Due to the large number of wind turbines and covering too large area in a large wind farm, wake effects among wind turbines and wind speed time delays will have a greater impact of wind farms models. Taking wind farms with doubly fed induction generator(DFIG) ... Keywords: wind farm, modeling, temporal and spatial characteristics, DFIG, output characteristics
Shupo Bu, Xunwen Su
Wind turbine rotor hub and teeter joint
A rotor hub is provided for coupling a wind turbine rotor blade and a shaft. The hub has a yoke with a body which is connected to the shaft, and extension portions which are connected to teeter bearing blocks, each of which has an aperture. The blocks are connected to a saddle which envelops the rotor blade by one or two shafts which pass through the apertures in the bearing blocks. The saddle and blade are separated by a rubber interface which provides for distribution of stress over a larger portion of the blade. Two teeter control mechanisms, which may include hydraulic pistons and springs, are connected to the rotor blade and to the yoke at extension portions. These control mechanisms provide end-of-stroke damping, braking, and stiffness based on the teeter angle and speed of the blade.
Coleman, Clint (Warren, VT); Kurth, William T. (Warren, VT); Jankowski, Joseph (Stowe, VT)
Fatigue reliability of wind turbine components
Fatigue life estimates for wind turbine components can be extremely variable due to both inherently random and uncertain parameters. A structural reliability analysis is used to qualify the probability that the fatigue life will fall short of a selected target. Reliability analysis also produces measures of the relative importance of the various sources of uncertainty and the sensitivity of the reliability to each input parameter. The process of obtaining reliability estimates is briefly outlined. An example fatigue reliability calculation for a blade joint is formulated; reliability estimates, importance factors, and sensitivities are produced. Guidance in selecting distribution functions for the random variables used to model the random and uncertain parameters is also provided. 5 refs., 9 figs., 1 tab.
Veers, P.S.
Structural health monitoring of wind turbines
To properly determine what is needed in a structural health monitoring system, actual operational structures need to be studied. We have found that to effectively monitor the structural condition of an operational structure four areas must be addressed: determination of damage-sensitive parameters, test planning, information condensation, and damage identification techniques. In this work, each of the four areas has been exercised on an operational structure. The structures studied were all be wind turbines of various designs. The experiments are described and lessons learned will be presented. The results of these studies include a broadening of experience in the problems of monitoring actual structures as well as developing a process for implementing such monitoring systems.
Simmermacher, T.; James, G.H. III.; Hurtado, J.E.
Liberty Turbine Test Wind Farm | Open Energy Information
Turbine Test Wind Farm Turbine Test Wind Farm Jump to: navigation, search Name Liberty Turbine Test Wind Farm Facility Liberty Turbine Test Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Developer Clipper Windpower Energy Purchaser Platte River Power Authority Location Near Medicine Bow WY Coordinates 41.96251°, -106.415918° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":41.96251,"lon":-106.415918,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Beijing Goldwind Kechuang Wind Turbine Manufacturer | Open Energy
Goldwind Kechuang Wind Turbine Manufacturer Goldwind Kechuang Wind Turbine Manufacturer Jump to: navigation, search Name Beijing Goldwind Kechuang Wind Turbine Manufacturer Place Beijing, Beijing Municipality, China Zip 100000 Sector Wind energy Product A manufacturer set up by Goldwind in Beijing for producing wind turbines. Coordinates 39.90601°, 116.387909° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":39.90601,"lon":116.387909,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Free-air performance tests of a 5-metre-diameter Darrieus turbine
A five-meter-diameter vertical-axis wind turbine has been tested at the Sandia Laboratories Wind Turbine Site. The results of these tests and some of the problems associated with free-air testing of wind turbines are presented. The performance data obtained follow the general trend of data obtained in extensive wind tunnel tests of a 2-meter-diameter turbine. However, the power coefficient data are slightly lower than anticipated. The reasons for this discrepancy are explored along with comparisons between experimental data and a computerized aerodynamic prediction model.
Sheldahl, R.E.; Blackwell, B.F.
www.cesos.ntnu.no Author Centre for Ships and Ocean Structures Offshore Wind Turbine Operation
1 www.cesos.ntnu.no Author Centre for Ships and Ocean Structures Offshore Wind Turbine Operation Structures Outline · Introduction · Wind Turbine Operational Conditions · Wind Turbine Operation under Atmospheric Icing · Wind Turbine Operation under Fault Condition · Conclusions www.cesos.ntnu.no M. Etemaddar
LQG Controller for a Variable Speed Pitch Regulated Wind Turbine
This paper deals with the design of LQG controllers for pitch regulated, variable speed wind turbines where the controller is used primarily for controlling the pitch angle through a collective pitch angle in the high wind speed in order to guarantee ... Keywords: LQG controller, Pitch control, Wind Trubine
Xingjia Yao; Shu Liu; Guangkun Shan; Zuoxia Xing; Changchun Guo; Chuanbao Yi
A Stator-Voltage Decoupling Control Strategy for DFIG-based Wind Power Turbine Supplying Local Isolated Load
The performance of doubly fed induction generator (DFIG) based wind turbines supplying local isolated load is manly up to the stator-voltage control strategy. Compared with conventional steady mathematic model based one, a dynamic mathematic model based ... Keywords: dynamic model, supplying local isolated load, decoupling stator-voltage control, DFIG-based wind turbine
Long Zhan; Shuying Yang; Hui Gao
Atmospheric Stability Impacts on Power Curves of Tall Wind Turbines - An Analysis of a West Coast North American Wind Farm
Tall wind turbines, with hub heights at 80 m or above, can extract large amounts of energy from the atmosphere because they are likely to encounter higher wind speeds, but they face challenges given the complex nature of wind flow and turbulence at these heights in the boundary layer. Depending on whether the boundary layer is stable, neutral, or convective, the mean wind speed, direction, and turbulence properties may vary greatly across the tall turbine swept area (40 to 120 m AGL). This variability can cause tall turbines to produce difference amounts of power during time periods with identical hub height wind speeds. Using meteorological and power generation data from a West Coast North American wind farm over a one-year period, our study synthesizes standard wind park observations, such as wind speed from turbine nacelles and sparse meteorological tower observations, with high-resolution profiles of wind speed and turbulence from a remote sensing platform, to quantify the impact of atmospheric stability on power output. We first compare approaches to defining atmospheric stability. The standard, limited, wind farm operations enable the calculation only of a wind shear exponent ({alpha}) or turbulence intensity (I{sub U}) from cup anemometers, while the presence at this wind farm of a SODAR enables the direct observation of turbulent kinetic energy (TKE) throughout the turbine rotor disk. Additionally, a nearby research meteorological station provided observations of the Obukhov length, L, a direct measure of atmospheric stability. In general, the stability parameters {alpha}, I{sub U}, and TKE are in high agreement with the more physically-robust L, with TKE exhibiting the best agreement with L. Using these metrics, data periods are segregated by stability class to investigate power performance dependencies. Power output at this wind farm is highly correlated with atmospheric stability during the spring and summer months, while atmospheric stability exerts little impact on power output during the winter and autumn periods. During the spring and summer seasons, power output for a given wind speed was significantly higher during stable conditions and significantly lower during strongly convective conditions: power output differences approached 20% between stable and convective regimes. The dependency of stability on power output was apparent only when both turbulence and the shape of the wind speed profile were considered. Turbulence is one of the mechanisms by which atmospheric stability affects a turbine's power curve at this particular site, and measurements of turbulence can yield actionable insights into wind turbine behavior.
Wharton, S; Lundquist, J K
Charts estimate gas-turbine site performance
Nomographs have been developed to simplify site performance estimates for various types of gas turbine engines used for industrial applications. The nomographs can provide valuable data for engineers to use for an initial appraisal of projects where gas turbines are to be considered. General guidelines for the selection of gas turbines are also discussed. In particular, site conditions that influence the performance of gas turbines are described.
Dharmadhikari, S.
Midwest Consortium for Wind Turbine Reliability and Optimization
This report provides an overview of the efforts aimed to establish a student focused laboratory apparatus that will enhance Purdue's ability to recruit and train students in topics related to the dynamics, operations and economics of wind turbines. The project also aims to facilitate outreach to students at Purdue and in grades K-12 in the State of Indiana by sharing wind turbine operational data. For this project, a portable wind turbine test apparatus was developed and fabricated utilizing an AirX 400W wind energy converter. This turbine and test apparatus was outfitted with an array of sensors used to monitor wind speed, turbine rotor speed, power output and the tower structural dynamics. A major portion of this project included the development of a data logging program used to display real-time sensor data and the recording and creation of output files for data post-processing. The apparatus was tested in an open field to subject the turbine to typical operating conditions and the data acquisition system was adjusted to obtain desired functionality to facilitate use for student projects in existing courses offered at Purdue University and Indiana University. Data collected using the data logging program is analyzed and presented to demonstrate the usefulness of the test apparatus related to wind turbine dynamics and operations.
Scott R. Dana; Douglas E. Adams; Noah J. Myrent
Atmospheric and Wake Turbulence Impacts on Wind Turbine Fatigue Loading: Preprint
Large-eddy simulations of atmospheric boundary layers under various stability and surface roughness conditions are performed to investigate the turbulence impact on wind turbines. In particular, the aeroelastic responses of the turbines are studied to characterize the fatigue loading of the turbulence present in the boundary layer and in the wake of the turbines. Two utility-scale 5 MW turbines that are separated by seven rotor diameters are placed in a 3 km by 3 km by 1 km domain. They are subjected to atmospheric turbulent boundary layer flow and data is collected on the structural response of the turbine components. The surface roughness was found to increase the fatigue loads while the atmospheric instability had a small influence. Furthermore, the downstream turbines yielded higher fatigue loads indicating that the turbulent wakes generated from the upstream turbines have significant impact.
Lee, S.; Churchfield, M.; Moriarty, P.; Jonkman, J.; Michalakes, J.
Yaw dynamics of horizontal axis wind turbines
Designers of a horizontal axis wind turbine yaw mechanism are faced with a difficult decision. They know that if they elect to use a yaw- controlled rotor then the system will suffer increased initial cost and increased inherent maintenance and reliability problems. On the other hand, if they elect to allow the rotor to freely yaw they known they will have to account for unknown and random, though bounded, yaw rates. They will have a higher-risk design to trade-off against the potential for cost savings and reliability improvement. The risk of a yaw-free system could be minimized if methods were available for analyzing and understanding yaw behavior. The complexity of yaw behavior has, until recently, discouraged engineers from developing a complete yaw analysis method. The objectives of this work are to (1) provide a fundamental understanding of free-yaw mechanics and the design concepts most effective at eliminating yaw problems, and (2) provide tested design tools and guidelines for use by free-yaw wind systems manufacturers. The emphasis is on developing practical and sufficiently accurate design methods.
Hansen, A.C. (Utah Univ., Salt Lake City, UT (United States))
Full Life Wind Turbine Gearbox Lubricating Fluids
Industrial gear box lubricants typically are hydrocarbon based mineral oils with considerable amounts of additives to overcome the lack of base fluid properties like wear protection, oxidation stability, load carrying capacity, low temperature solidification and drop of viscosity at higher temperatures. For today's wind turbine gearboxes, the requirements are more severe and synthetic hydrocarbon oils are used to improve on this, but all such hydrocarbon based lubricants require significant amounts of Extreme Pressure (EP) additives to meet performance requirements. Perfluoropolyether (PFPE) fluids provide load carrying capacity as an inherent property. During the course of the project with the main tasks of 'Establish a Benchmark', 'Lubricant Evaluation', 'Full Scale Gearbox Trial' and 'Economic Evaluation', the PAO Reference oil exhibited significant changes after laboratory gear testing, in service operation in the field and full scale gearbox trial. Four hydrocarbon base oils were selected for comparison in the benchmarking exercise and showed variation with respect to meeting the requirements for the laboratory micro-pitting tests, while the PFPE fluid exceeded the requirements even with the material taken after the full scale gear box trial. This is remarkable for a lubricant without EP additives. Laboratory bearing tests performed on the PFPE fluids before and after the full scale gear box trial showed the results met requirements for the industry standard. The PFPE fluid successfully completed the full scale gear box test