Electricity sector in Argentina

The electricity sector in Argentina constitutes the third largest power market in Latin America. It relies mostly on thermal generation (60% of installed capacity) and hydropower generation (36%). The prevailing natural gas-fired thermal generation is at risk due to the uncertainty about future gas supply.
Faced with rising electricity demand (over 6% annually) and declining reserve margins, the government of Argentina is in the process of commissioning large projects, both in the generation and transmission sectors. To keep up with rising demand, it is estimated that about 1,000 MW of new generation capacity are needed each year. An important number of these projects are being financed by the government through trust funds, while independent private initiative is still limited as it has not fully recovered yet from the effects of the 2002 Argentine economic crisis.
The electricity sector was unbundled in generation, transmission and distribution by the reforms carried out in the early 1990s. Generation occurs in a competitive and mostly liberalized market in which 75% of the generation capacity is owned by private utilities. In contrast, the transmission and distribution sectors are highly regulated and much less competitive than generation.
Electricity supply and demand.
Generation.
Thermal plants fueled by natural gas (CCGT) are the leading source of electricity generation in Argentina. Argentina generates electricity using thermal power plants based on fossil fuels (60%), hydroelectric plants (36%), and nuclear plants (3%), while wind and solar power accounted for less than 1%. Installed nominal capacity in 2019 was 38,922 MW. However, this scenario of gas dominance is likely to undergo changes due to gas exhaustion derived from the existing "bottlenecks" in exploration and production (E+P) and pipeline capacity. Gas output dropped for the first time in 2005 (-1.4%) and gas reserves dropped to ten years of consumption by the end of 2004 (down from an average of 30 years in the 1980s). Today, gas reserves are 43% lower than in 2000. This situation is further aggravated by the uncertainty surrounding the gas deals with Bolivia and the plans to build new regional pipeline connections. Total generation in 2005 was 96.65 TW·h. In 2015, the Atucha II Nuclear Power Plant reached 100% power, increasing the percentage of nuclear power in Argentina from 7% to 10%.The generators are divided into eight regions: Cuyo (CUY), Comahue (COM), Northwest (NOA), Center (CEN), Buenos Aires/Gran Buenos Aires (GBA-BAS), Littoral (LIT), Northeast (NEA) and Patagonia (PAT).
Installed capacity in the wholesale market as of December 2020:
The above table does not consider off-grid installed capacity nor distributed generation (small biogas/biomass facilities, rooftop solar panels, etc.)
While CAMESSA categorises hydropower larger than 50MW as non-renewable, the renewable classification of large hydropower is in line with international standars and how other countries classify their hydropower as renewable energy. Pumped storage is considered as non-renewable due to its consumption of electricity from the grid.
Imports and exports.
In 2005, Argentina imported 6.38 TW·h of electricity while it exported 3.49 TW·h. Net energy imports thus were about 3% of consumption.
Argentina also imports electricity from Paraguay, produced by the jointly built Yaciretá Dam. On 18 September 2006 Paraguay agreed to settling its debt of $11,000,000,000 owed to Argentina for the construction of Yaciretá by paying in electricity, at the rate of 8,000 GWh per year for 40 years.
Demand.
Electricity demand in Argentina has steadily grown since 1991, with just a temporary decline caused by the economic crisis of 2001-2002 that has been followed by a quick recovery (6%-8% annual increase) in the last five years, partially due to economic recovery. In 2005, the country consumed 94.3 TW·h of electricity, which corresponds to 2,368 kWh per capita. Residential consumption accounted for 29% of the total, while industrial, and commercial and public represented 43% and 26% respectively.
Demand and supply projections.
Argentina currently faces a tight supply/demand scenario as reserve margins have declined from above 30% in 2001 to less than 10%. This fact, together with the deterioration in distribution companies services (i.e. cables, transformers, etc.), has the potential to endanger supply. To sustain a 6-8% annual increase in demand, it is estimated that the system should incorporate about 1,000 MW of generation capacity each year.
Transmission and distribution.
In Argentina, there are two main wide area synchronous grids systems, SADI ("Sistema Argentino de Interconexión", Argentine Interconnected System) in the North and center-South of the country, and SIP ("Sistema de Interconexión Patagónico", Patagonian Interconnected System) in the South. Both systems are integrated since March 2006. The electricity market in the SADI area is managed by the MEM ("Mercado Eléctrico Mayorista").
Access to electricity.
Total electricity coverage in Argentina was close to 100% of the population in 2016. However, access to electricity is more deficient in certain rural areas. The Renewable Energy in the Rural Market Project (PERMER) in 2012 was one of several programs being implemented to enlarge electricity coverage in rural areas. (See World Bank projects below).
Service quality.
Interruption frequency and duration.
Interruption frequency and duration are considerably below the averages for the LAC region. In 2002, the average number of interruptions per subscriber was 5.15, while duration of interruptions per subscriber was 5.25 hours. The weighted averages for LAC were 13 interruptions and 14 hours respectively.
Distribution and transmission losses.
Distribution losses in 2005 were 13.6%, down from 17% a decade before. In 2014, losses were about 3.3%.
Responsibilities in the Electricity Sector.
Policy and regulation.
The Energy Secretariat (SENER) is responsible for policy setting, while the National Electricity Regulator (ENRE) is the independent entity within the Energy Secretariat responsible for applying the regulatory framework established by Law 26,046 of 1991. ENRE is in charge of regulation and overall supervision of the sector under federal control. Provincial regulators regulate the rest of the utilities. ENRE and the provincial regulators set tariffs and supervise compliance of regulated transmission and distribution entities with safety, quality, technical and environmental standards. CAMMESA ("Compañía Administradora del Mercado Mayorista Eléctrico") is the administrator of the wholesale electricity market. Its main functions include the operation and dispatch of generation and price calculation in the spot market, the real-time operation of the electricity system and the administration of the commercial transactions in the electricity market.
The Electric Power Federal Council (CFEE), created in 1960, plays a very important role in the sector as well. It is the administrator of funds that specifically target electricity operations (i.e. National Fund for Electric Power, see Recent developments below) and is also an adviser to the National and the Provincial Governments in issues relating to the power industry, public and private energy services, priorities in the execution of new projects and studies, concessions and authorizations, and electricity tariffs and prices. It is also an adviser for legislative modifications in the power industry.
The Argentine power sector is one of the most competitive and deregulated in South America. However, the fact that the Energy Secretariat has veto power over CAMMESA has the potential to alter the functioning of the competitive market. The functions of generation, transmission, and distribution are open to the private sector, but there are restrictions on cross-ownership between these three functions. Argentine law guarantees access to the grid in order to create a competitive environment and to allow generators to serve customers anywhere in the country.
Generation.
Private and state-owned companies carry out generation in a competitive, mostly liberalized electricity market, with 75% of total installed capacity in private hands. The share in public hands corresponds to nuclear generation and to the two bi-national hydropower plants: Yacyretá (Argentina-Paraguay) and Salto Grande (Argentina-Uruguay). The generation sector is highly fragmented with more than ten large companies, all of them providing less than 15% of the system's total capacity. Power generators sell their electricity in the wholesale market operated by the CAMMESA.
Transmission and distribution.
The transmission and distribution sectors are highly regulated and less competitive than generation. In transmission, the Compañía Nacional de Transporte Energético en Alta Tension (Transener) operates the national electricity transmission grid under a long-term agreement with the Argentine government. In the distribution sector, three private companies, Edenor ("Empresa Distribuidora y Comercializadora Norte"), Edesur ("Electricidad Distribuidora Sur") and Edelap ("Empresa de Electricidad de la Plata"), dominate a market with 75% control by private firms.
Other important distribution companies at the provincial level are:
Renewable energy resources.
The National Promotion Direction (DNPROM) within the Energy Secretariat (SENER) is responsible for the design of programs and actions conducive to the development of renewable energies (through the Renewable Energy Coordination) and energy efficiency (through the Energy Efficiency Coordination) initiatives. Complementarily, the Secretariat for the Environment and Natural Resources (SEMARNAT) is responsible for environmental policy and the preservation of renewable and non-renewable resources.
The most important legal instruments for the promotion of renewable energy are Law 25,019 from 1998 and Law 26,190 from 2007. The 1998 law, known as the "National Wind and Solar Energy Rules", declared wind and solar generation of national interest and introduced a mechanism that established an additional payment per generated kWh which, in 1998, meant a 40% premium over market price. It also granted certain tax exemptions for a period of 15 years from the law's promulgation. The 2007 Law complemented the previous one, declaring of national interest the generation of electricity from any renewable source intended to deliver a public service. This law also set an 8% target for renewable energy consumption in the period of 10 years and mandated the creation of a trust fund whose resources will be allocated to pay a premium for electricity produced from renewable sources.
Argentina can gain significant geopolitical benefits after the global transition to renewable energy is completed; it is ranked no. 10 among 156 countries in the index of geopolitical gains and losses after energy transition (GeGaLo Index).
Hydropower.
Argentina's hydroelectric potential is being exploited only partially. While the identified potential is 170,000 GW·h/year, in 2006 hydroelectric production amounted just to 42,360 GW·h. There are also untapped mini-hydropower resources, whose potential is estimated at 1.81% of overall electricity production (in contrast with its current 0.88%).
Wind.
The Argentine Patagonia region has a very large wind potential. The Chubut Wind Power Regional Center (CREE) estimated the theoretical potential for the region at 500 GW of electricity generation. However, this large potential is still largely unexploited. One of the reasons for this underdevelopment is that existing tariffs and incentives do not make wind power development attractive enough yet. However, the main deterrent to wind power development in the region has been the lack of transmission lines that connect the Patagonia region with the National Interconnected System. The completion of the Choele-Choel-Puerto Madryn high voltage line, the first section of "Línea Patagónica" under the framework of the "Plan Federal de Transporte de Energía Eléctrica", eliminated this bottleneck in March 2006.
Nevertheless, wind power has increased significantly in Argentina during the last decade. Total operating wind power capacity in 2005 was 26.6 MW, shared by 13 plants. This is still only about 0.05% of the theoretical potential of wind energy in Argentina. In 2007, the distribution of number plants and total capacity was:
Of the 13 plants, only three have been commissioned after the year 2000, with the remaining 10 built during the 1990s.
(See Wind power regime map for Argentina).
Solar.
Solar power is only present in remote areas. Just 81 MW·h were generated in 2005, less than 0.1% of total electricity production. In 2012 the first of four 5 MW stages of Cañada Honda was completed, as part of a plan to install 117 MW of renewable energy.
History of the electricity sector.
The reforms of 1991/92.
Prior to 1991, the electricity sector in Argentina was vertically integrated. The sector experienced a serious crisis in the summers of 1988/1989, primarily due to the lack of maintenance of the country's thermal power plants (50% were unavailable). Shortly after the crisis, the government of Carlos Menem introduced a new legal framework for the electricity sector through Law 24,065, which included the following elements: vertical and horizontal unbundling of generation, transmission and distribution; opening up of all segments to the private sector; and separation of the regulatory function from policy setting. As a result of the new law, there was substantial private investment which, together with the public power plants that started production in the 1990s, transformed a situation of power shortage and low quality into one of abundance and reliability at lower prices.
ENRE (Electricity National Regulatory Entity) was created in 1992. The Wholesale Electricity Market (MEM), which covers up to 93% of total demand corresponding to the Argentine Interconnected System (SADI), was also created in 1992. The remaining 7% share of the demand corresponds to Patagonia, which had its own interconnected market, the Patagonian Wholesale Electricity Market MEMSP), now interconnected with the MEM. CAMMESA (Wholesale Electricity Market Administration Company) was also created that year and assigned the responsibilities of coordinating dispatch operations, setting wholesale prices and administrating economic transactions performed through the Argentine Interconnected System.
The reforms implemented in the 1990s led to high investment, which allowed for a 75% increase in generation capacity, resulting in the decrease of prices in the wholesale market from US$40/MW·h in 1992 to US$23/MW·h in 2001. However, the reforms failed to deliver the necessary increase in transmission capacity. Only one relevant project, the addition of the 1,300 km high voltage line between Comahue and Buenos Aires, was built in the 1990s. Distribution networks were also renovated and expanded, which resulted in efficiency and quality improvements.
Tariff freeze.
As a response to the 2001 economic crisis, electricity tariffs were converted to the Argentine peso and frozen in January 2002 through the Public Emergency and Exchange Regime Law. Together with high inflation (see Economy of Argentina) and the devaluation of the peso, many companies in the sector had to deal with high levels of debt in foreign currency under a scenario in which their revenues remained stable while their costs increased. This situation has led to severe underinvestment and unavailability to keep up with an increasing demand, factors that contributed to the 2003-2004 energy crisis. Since 2003, the government has been in the process of introducing modifications that allow for tariff increases. Industrial and commercial consumers' tariffs have already been raised (near 100% in nominal terms and 50% in real terms), but residential tariffs still remain the same.
Creation of Enarsa.
In 2004, President Néstor Kirchner created "Energía Argentina Sociedad Anónima" (Enarsa), a company managed by the national state of Argentina for the exploitation and commercialization of petroleum and natural gas, but also the generation, transmission and trade of electricity. Through the creation of Enarsa, the state will regain a relevant place in the energy market that was largely privatized during the 1990s.
Energy Plus and Gas Plus programs.
In September 2006, SENER launched the Energy Plus ("Energía Plus") program with the objective of increasing generation capacity and meeting the rising demand for electricity. The program applies for consumption levels above those for 2005. CAMMESA requires all large users (above 300 kW) to contract the difference between their current demand and their demand in the year 2005 in the Energy Plus market. In this new de-regulated market, only energy produced from new generation plants will be traded. The aim of the program is twofold. In one hand, it seeks to guarantee supply to residential consumers, public entities, and small and medium enterprises. On the other hand, it aims at encouraging self-generation by the industrial sector and electricity cogeneration.
In March 2008, the government approved Resolution 24/2008, which created a new natural gas market called "Gas Plus" to encourage private investment in natural gas exploration and production. The Gas Plus regime applies to new discoveries and to "tight gas" fields. The price of the new gas, whose commercialization will be restricted to the domestic market, will not be subject to the conditions established in the "Agreement with Natural Gas Producers 2007-2011" but will be based on costs and a reasonable profit. Experts believe that, if the Gas Plus regime is successful, it could stimulate new investments in electricity generation plants under the Energy Plus regime as it could ensure fuel supply to the new plants.
The National Program for the Rational and Efficient Use of Energy (PRONUREE).
In December 2007, the government launched the National Program for the Rational and Efficient Use of Energy (PRONUREE, Decree 140/2007). This decree declared the rational and efficient use of energy to be in the national interest and is also part of the energy sector strategy to counter supply/demand imbalance. The PRONUREE, under the responsibility of the Secretariat of Energy, aims to be a vehicle for improving energy efficiency in the energy-consuming sectors and acknowledges that energy efficiency needs to be promoted with a long-term commitment and vision. It also acknowledges the connection between energy efficiency and sustainable development, including the reduction of greenhouse gas emissions. The program also recognizes the need for individual behavioral changes to be promoted with an educational strategy, with the public sector setting the example by assuming a leadership role in the implementation of energy conservation measures in its facilities.
The PRONUREE includes short- and long-term measures aimed at improving the energy efficiency in the industrial, commercial, transport, residential and service sectors and public buildings. It also supports educational programs on energy efficiency, enhanced regulations to expand cogeneration activities; labeling of equipment and appliances that use energy; improvements to the energy efficiency regulations; and broader utilization of the Clean Development Mechanism (CDM) to support the development of energy efficiency projects. The objective of the program is to reduce electricity consumption by 6%.
One of the first activities defined under PRONUREE is the national program to phase out incandescent bulbs by 2011 in Argentina. The program, financed by the government, aims to replace incandescent bulbs with energy efficient compact fluorescent lamps (CFLs) in all households connected to the electricity grid and selected public buildings. The program, which has initially undergone a pilot phase and expects to replace 5 million incandescent lamps in the next six months, foresees the distribution of 25 million lamps overall. Staff from the distribution companies will visit each household to replace the incandescent lamps and to inform residential users on the advantages of replacing the bulbs and of the efficient use of energy in general.
Recent tariff increases, 2008.
In Argentina, retail tariffs for the distribution utilities in the Metropolitan Area of Buenos Aires and La Plata city (i.e. Edenor, Edesur and Edelap) are regulated by the national regulatory agency (ENRE) while provincial utilities are regulated by local regulators. While the utilities under ENRE's jurisdiction had not been allowed to raise residential tariffs since they were frozen in 2002 as a result of the Emergency and Exchange Regime Law, some provincial regulators had recently approved additional charges to residential tariffs. In particular, the Public Service Regulatory Agency in the Province of Córdoba (ERSeP) agreed in February 2008 to a 17.4% additional charge to residential customers. Likewise, Santa Fé approved increases between 10% and 20%; Mendoza between 0 and 5% below 300 kWh and between 10% and 27% above 300 kWh; Jujuy between 22% and 29% and Tucumán between 10% and 24%. Other provinces (i.e. San Juan, Chaco, Formosa, Corrientes, La Pampa, Neuqen, Río Negro and Entre Ríos) are expected to raise tariffs in the near future.
Recently, in August 2008, after a 7-year tariff freeze, residential electricity tariffs in the Buenos Aires metropolitan area (served by the Edenor, Edesur and Edelap utilities) have been increased by 10-30% for households that consume more than 650 kWh every two months. For consumption between 651 kWh and 800 kWh, the increase will be 10%; on the other end, for users over 1,201 kWh, the increase amounts to 30%. The increase impacts around 24% of all Edenor, Edesur and Edelap customers (1,600,000 households). For commercial and industrial users the increase will be 10%.
At the end of August 2008, ENRE also approved increases in transmission tariffs in the 17%-47% range. The increase granted by ENRE was below the increase determined by the Energy Secretariat for some transmission companies (e.g. Transener, Transba, Distrocuyo and Transnoa. Some of them (i.e. Transener, Transba), will most likely challenge ENRE's decision. An overall tariff revision is still pending and has been put off until February 2009.
Tariffs, cost recovery and subsidies.
Tariffs.
Electricity tariffs in Argentina are well below the LAC average. In 2004, the average residential tariff was US$0.0380 per kWh, very similar to the average industrial tariff, which was US$0.0386 per kWh in 2003. Weighted averages for LAC were US$0.115 per kWh for residential consumers and US$0.107 per kWh for industrial customers.
(See History of the electricity sector for more information on the evolution of tariffs).
Subsidies.
See Fund for the Electric Development of the Interior (FEDEI) below.
Investment and financing.
In 1991, the Government of Argentina created the National Fund for Electric Power (FNEE, "Fondo Nacional de la Energía Eléctrica"), to be funded by a share of the petrol tax and a surcharge on sales from the wholesale market. This Fund, which is administered by CFEE (Electric Power Federal Council), provides funding to the following other funds at the shares indicated:
In addition, CAMMESA, the administrator of the wholesale electricity market, had projected that by 2007 the country's energy demand would require an additional capacity of 1,600 MW. Faced with the need for specific investments but also with a lack of private investment, the Energy Secretariat (SENER) enacted Resolutions 712 and 826 in 2004, which created FONINVEMEM, the Fund for the Investment Needed to Increase the Supply of Electricity in the Wholesale Market. The Fund, which sought to encourage participation from creditors of the wholesale market, invited those creditors, mainly generation companies, to participate with their credit in the creation of the Fund itself.
Ongoing projects.
There are several projects that are part of the government's response to the predicted electricity shortages. If all those plans are completed as expected, the capacity requirements for the next few years will be met.
Thermal power.
Two new CCGT plants, the José de San Martín Thermoelectric and Manuel Belgrano Thermoelectric, of 830 MW each, are under construction and expected to start full operations at the beginning of 2009. Endesa, Total S.A., AES Corporation, Petrobras, EDF and Duke Energy are the main shareholders in the plants. Both plants, which have been financed through the FONINVEMEM (total investment amounts up to US$1,097 million), are expected to start full operations at the beginning of 2009.
In addition, the Planning Ministry announced in July 2007 the commissioning of five new thermal plants with a total capacity of 1.6 GW and an overall investment of US$3,250 million. These dual-generation turbine (gas or fuel oil) plants, which are expected to start operations in 2008, will be located in Ensenada (540 MW), Necochea (270 MW), Campana (540 MW), Santa Fe (125 MW) and Córdoba (125 MW). Finally, Enarsa has recently launched bidding for eleven small and transportable generation units (15-30 MW each) and for other three larger generation units (50-100 MW) to be installed on barges. These new units, whose base price is still unknown, will add between 400 and 500 MW of new generation capacity.
Nuclear power.
In 2006, the Argentine government launched a plan to boost nuclear energy. The Atucha II nuclear power plant, whose construction started in 1981, will be completed and will add 750 MW of generation capacity by 2010. In addition, the Embalse nuclear power plant, with 648 MW of generation capacity, will be refurbished to extend its operational life beyond 2011.
Hydropower.
On the hydropower side, the Yacyretá dam's reservoir was elevated by 7 m to the height of 83 m as contemplated in its original design, which increased its capacity from 1,700 to 3,100 MW. This will lead to a 60% increase in its electricity output (from 11,450 GW·h to 18,500 GW·h). The reservoir rise was complete in February 2011 despite a serious controversy regarding the resettlement of people. Additionally, in 2006, bidding for the expansion of Yacyretá with the construction of a new 3-turbine plant in the Añá Cuá arm of the Paraná River was announced by the Government. This expansion, to be finalized in 2010, would add 300 MW of new generation capacity.
Transmission.
In regard to transmission, the Federal Plan for Transport of Electric Energy at 500 kV is under implementation under the umbrella of the FFTEF (Fondo Fiduciario para el Transporte Eléctrico Federal). The main lines of the plan (Línea Patagónica, Línea Minera, Yacyretá, Puerto Madryn – Pico Truncado, NEA-NOA, Comahue – Cuyo, Pico Truncado – Río Turbio – Río Gallegos) are already built or currently under construction. The lines built between 2007 and 2009 will add 4,813 new kilometers of high voltage transmission capacity.
In addition, the Federal Plan for Transport of Electric Energy II, defined in 2003 and updated in 2006, has the objective of addressing the constraints faced by the regional transmission networks in the period up to 2010. This complementary plan has prioritized the necessary works according to their ability to address short-term demand issues. 109 of the 240 works identified in 2003 were considered of high priority and have already been completed or are under execution. Initially, investment for high priority works was estimated at US$376 million, while estimated investment for the rest of the works totaled US$882.2 million. However, this budget is under revision due to the increasing costs of materials such as steel and aluminum and of labor.
Summary of private participation in the electricity sector.
Prior to 1991, the electricity sector in Argentina was vertically integrated. The new legal framework for the electricity sector included: vertical and horizontal unbundling of generation, transmission and distribution; opening up of all segments to the private sector; and separation of the regulatory function from policy setting.
Currently, private and state-owned companies carry out generation in a completive, mostly liberalized electricity market, with 75% of total installed capacity in private hands. The publicly owned share corresponds to nuclear generation and to the two bi-national hydropower plants: Yacyretá (Argentina-Paraguay) and Salto Grande (Argentina-Uruguay). On the other hand, the transmission and distribution sectors are highly regulated and less competitive than generation. In transmission, the Compañía Nacional de Transporte Energético en Alta Tension (Transener) operates the national electricity transmission grid, while in the distribution sector, three private companies, Edenor (Empresa Distribuidora y Comercializadora Norte), Edesur (Electricidad Distribuidora Sur) and Edelap (Empresa de Electricidad de la Plata), dominate a market with 75% control by private firms.
Electricity and the Environment.
Responsibility for the environment.
The Secretariat of Environment and Sustainable Development holds responsibility for the environment in Argentina.
Greenhouse gas emissions.
OLADE (Organización Latinoamericana de Energía) estimated that CO2 emissions from electricity production in 2003 were 20.5 million tons of CO2, which represents 17% of total emissions for the energy sector.
In 2011, according to the International Energy Agency, the actual CO2 emissions from electricity generation were 67.32 million metric tons, a share of 36.7% of the countries' total CO2 emissions from fuel combustion.
CDM projects in electricity.
As of August 2007, there are only three energy-related registered CDM projects in Argentina, with expected total emissions reductions of 673,650 tons of CO2e per year. Of the three projects, only one is large-scale: the 10.56 MW Antonio Morán wind power plant in the Patagonia region. Production of electricity from biomass waste in the Aceitera General Deheza and methane recovery and electricity generation from the Norte III-B landfill are the two small-scale existing projects.
External assistance.
World Bank.
The only active energy project financed by the World Bank in Argentina is the Renewable Energy in the Rural Market Project (PERMER). This project has the objective of guaranteeing access to electricity to 1.8 million people (314,000 households) and to 6,000 public services (schools, hospitals, etc.) located far from electricity distribution centers. Electrification of this dispersed market will be mostly carried out through the installation of solar photovoltaic systems, but also through other technologies such as micro-hydraulic turbines, wind and, eventually, diesel generators. The project, which started in 1999 and is expected to end in December 2008, has received a US$10 million grant from GEF and a US$30 million loan from the World Bank. The Argentine Energy Secretariat has recently presented an Energy Efficiency project to the GEF. The objective of the project is to improve energy use, reducing its costs to consumers and contributing to the sustainability of the energy sector in the long term. A reduction in greenhouse gas emissions is also sought.
Inter-American Development Bank.
In November 2006, the Inter-American Development Bank approved a $580 million loan for the construction of a new 760-mile transmission line in northern Argentina that will connect separate grids in the northeastern and northwestern parts of the country, the Norte Grande Electricity Transmission Program.
Andean Development Corporation (CAF).
In 2006, Argentina received financing from CAF (Andean Development Corporation) for two electricity projects: the Electricity Interconection Comahue-Cuyo (US$200 million) and the Electricity Interconnection Rincón Santa María-Rodríguez (US$300 million), two of the high voltage transmission lines included in the Federal Transportation Plan. In the same year, Argentina also borrowed US$210 million from CAF for a program that aims at repairing the country's hydroelectric infrastructure.
In June 2007, CAF approved a US$45 million loan to the Buenos Aires province for partial financing of the electricity transport capacity in the North of the province.


Alaska Interconnection

The Alaska Interconnection (ASCC) is an AC power transmission grid in North America that serves Central and Southeast Alaska. While the Alaska Interconnection is often referred to as one interconnected grid, its two parts are not connected to each other through interconnectors, nor are the two grids connected to any other interconnection, making the grids in Alaska isolated circuits. Both grids, though, are managed by the Alaska Systems Coordinating Council as if they were one entity like the other interconnections in North America.
Production.
The Alaska Interconnection is the smallest individual power transmission grid in North America compared to the three other major interconnections – the Western Interconnection, the Eastern Interconnection, and the Texas Interconnection – both in physical area and electricity generated. In 2015, the Alaska interconnection generated 2,601 gigawatt hours of electricity, with natural gas accounting for 1,219 GWh, while the US State of Washington alone – part of the Western Interconnection – generated 47,385 GWh. While both parts of the Alaska Interconnection have no connection to remaining interconnections of North America, all generating units connected to both of its grids generate at a synchronous speed of 60 Hz, the frequency common to North America. Electricity is also delivered to homes and small businesses in the same manner as in Canada and the contiguous United States with a split-phase 240/120 volt service.
Isolation from other power grids.
In 2014, an interconnector to the Western Interconnection of British Columbia was proposed to the Alaska Energy Authority in order to bring cleaner, cheaper power to Alaska, but as of 2016, no further work on the project had been completed due to economic feasibility.
Impact to cost.
Because the transmission networks in Alaska are isolated from other interconnections in North America, average rates for electricity are $0.18 per kWh – the second highest price in the United States after Hawaii, whose average residential rate is $0.37 per kWh. In contrast, the average rate for electricity in the 48 contiguous states is $0.10 per kWh.


Sabah Gas Industries

Sabah Gas Industries Sdn Bhd was a state owned holding company based in Labuan, Malaysia. It was established in 1982 by the Government of Sabah for the downstream operations of Sabah natural gas resources. The company owned and operated a 660,000-tonne per year methanol plant, a 600,000-tonne per year sponge iron factory, and a 79 MW natural gas-fired power station, all commissioned in 1984 after the gas pipeline from the offshore gas fields became operational. The industries were supplied by natural gas from the Erb West and Samarang offshore fields. In the beginning of the 1990s, due to financial difficulties, the company was put for privatisation. In 1992, the methanol plant was sold to Petronas and operates today as Petronas Methanol (Labuan) Sdn Bhd. The power station was sold to Sabah Electricity. The sponge iron factory was bought by the affiliated companies of the today's Lion Group. The plant operates today as Antara Steel Mills Sdn Bhd.


Integral Energy

Integral Energy was the second largest state-owned energy corporation in New South Wales, incorporated under the Energy Services Corporations Act 1995 from a merger between Prospect Electricity and Illawarra Electricity. Integral Energy was involved in electricity retail in addition to owning an electricity distribution network and previously held licences to retail electricity in the contestable markets covered by the NEM (National Electricity Market).
At its height, Integral Energy distributed and retailed electricity and services to 807,000 customers, or 2.1 million people. In addition to electricity retailing, Integral Energy also owned an electricity distribution network spanning 24,500 square kilometres in Greater Western Sydney, the Illawarra, and the Southern Highlands.
In 2011, their network value was estimated at A$2 billion and was made up of 25,000 transmission, zone and distribution substations, 370,000 power poles and 150,000 streetlights bound together by 33,000 kilometres of underground and overground cables. Integral Energy did not have a monopoly on the sale of energy within its distribution area and was in competition with private sector retailers such as AGL and Origin Energy since the introduction of full retail contestability in New South Wales.
The CEO was Vince Graham (formerly of RailCorp), who replaced Richard Powis on 7 April 2008.
Fifteen Integral Energy field service centres operated within their franchise, with staff maintaining the network, repairing faults, responding to emergencies and servicing customers and developers in relation to customer connection and contestable projects. The centres were located in Bowenfels, , Hoxton Park, Kandos, Katoomba, Moss Vale, Narellan, Nowra, Parramatta, Penrith, Picton, Shellharbour, Springhill, Ulladulla and South Windsor.
The retail division of the company, along with the Integral Energy brand, was sold by the NSW Government in 2011 to Origin Energy. Integral Energy (Networks) was rebranded to Endeavour Energy as part of the NSW Government reform. In June 2017, an Australian-led consortium of institutional investors acquired 50.4% ownership of the rights to management Endeavour Energy’s network assets under a 99-year lease. The consortium was led by Macquarie Infrastructure and Real Assets (MIRA), and includes AMP Capital, British Columbia Investment Management Corporation and Qatar Investment Authority.


Powernext

Powernext SA, incorporated in 2001, is a regulated market operating under AMF supervision. Based in Paris, Powernext manages the natural gas activities of the EEX Group under the PEGAS brand throughout Europe, and operates the National Registry for electricity guarantees of origin in France.
As of 1 January 2016, the European Energy Exchange (EEX) is the majority shareholder with 87.73 percent of the Powernext shares.
A decree by the French Ministry of Ecology, Sustainable Development and Energy, published on 15 January 2013 in the Official Journal, appointed Powernext as the National Registry for electricity guarantees of origin in France. Powernext succeeded RTE as the guarantee of origin issuing body on 1 May 2013 for a five-year term.


Photovoltaic system

A photovoltaic system, also PV system or solar power system, is a power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and convert sunlight into electricity, a solar inverter to convert the output from direct to alternating current, as well as mounting, cabling, and other electrical accessories to set up a working system. It may also use a solar tracking system to improve the system's overall performance and include an integrated battery solution, as prices for storage devices are expected to decline. Strictly speaking, a solar array only encompasses the ensemble of solar panels, the visible part of the PV system, and does not include all the other hardware, often summarized as balance of system (BOS). As PV systems convert light directly into electricity, they are not to be confused with other solar technologies, such as concentrated solar power or solar thermal, used for heating and cooling.
PV systems range from small, rooftop-mounted or building-integrated systems with capacities from a few to several tens of kilowatts, to large utility-scale power stations of hundreds of megawatts. Nowadays, most PV systems are grid-connected, while off-grid or stand-alone systems account for a small portion of the market.
Operating silently and without any moving parts or environmental emissions, PV systems have developed from being niche market applications into a mature technology used for mainstream electricity generation. A rooftop system recoups the invested energy for its manufacturing and installation within 0.7 to 2 years and produces about 95 percent of net clean renewable energy over a 30-year service lifetime.
Due to the growth of photovoltaics, prices for PV systems have rapidly declined since their introduction. However, they vary by market and the size of the system. In 2014, prices for residential 5-kilowatt systems in the United States were around $3.29 per watt, while in the highly penetrated German market, prices for rooftop systems of up to 100 kW declined to €1.24 per watt. Nowadays, solar PV modules account for less than half of the system's overall cost, leaving the rest to the remaining BOS-components and to soft costs, which include customer acquisition, permitting, inspection and interconnection, installation labor and financing costs.
Modern system.
Overview.
A photovoltaic system converts the sun's radiation, in the form of light, into usable electricity. It comprises the solar array and the balance of system components. PV systems can be categorized by various aspects, such as, grid-connected vs. stand alone systems, building-integrated vs. rack-mounted systems, residential vs. utility systems, distributed vs. centralized systems, rooftop vs. ground-mounted systems, tracking vs. fixed-tilt systems, and new constructed vs. retrofitted systems. Other distinctions may include, systems with microinverters vs. central inverter, systems using crystalline silicon vs. thin-film technology, and systems with modules from Chinese vs. European and U.S.-manufacturers.
About 99 percent of all European and 90 percent of all U.S. solar power systems are connected to the electrical grid, while off-grid systems are somewhat more common in Australia and South Korea. PV systems rarely use battery storage. This may change, as government incentives for distributed energy storage are implemented and investments in storage solutions gradually become economically viable for small systems. A typical residential solar array is rack-mounted on the roof, rather than integrated into the roof or facade of the building, which is significantly more expensive. Utility-scale solar power stations are ground-mounted, with fixed tilted solar panels rather than using expensive tracking devices. Crystalline silicon is the predominant material used in 90 percent of worldwide produced solar modules, while its rival thin-film has lost market-share. About 70 percent of all solar cells and modules are produced in China and Taiwan, only 5 percent by European and US-manufacturers. The installed capacity for both, small rooftop systems and large solar power stations is growing rapidly and in equal parts, although there is a notable trend towards utility-scale systems, as the focus on new installations is shifting away from Europe to sunnier regions, such as the Sunbelt in the U.S., which are less opposed to ground-mounted solar farms and cost-effectiveness is more emphasized by investors.
Driven by advances in technology and increases in manufacturing scale and sophistication, the cost of photovoltaics is declining continuously. There are several million PV systems distributed all over the world, mostly in Europe, with 1.4 million systems in Germany alone– as well as North America with 440,000 systems in the United States. The energy conversion efficiency of a conventional solar module increased from 15 to 20 percent since 2004 and a PV system recoups the energy needed for its manufacture in about 2 years. In exceptionally irradiated locations, or when thin-film technology is used, the so-called energy payback time decreases to one year or less.
Net metering and financial incentives, such as preferential feed-in tariffs for solar-generated electricity, have also greatly supported installations of PV systems in many countries. The levelised cost of electricity from large-scale PV systems has become competitive with conventional electricity sources in an expanding list of geographic regions, and grid parity has been achieved in about 30 different countries.
As of 2015, the fast-growing global PV market is rapidly approaching the 200 GW mark – about 40 times the installed capacity in 2006. These systems currently contribute about 1 percent to worldwide electricity generation. Top installers of PV systems in terms of capacity are currently China, Japan and the United States, while half of the world's capacity is installed in Europe, with Germany and Italy supplying 7% to 8% of their respective domestic electricity consumption with solar PV. The International Energy Agency expects solar power to become the world's largest source of electricity by 2050, with solar photovoltaics and concentrated solar thermal contributing 16% and 11% to the global demand, respectively.
Solar Grid-connection.
A grid connected system is connected to a larger independent grid (typically the public electricity grid) and feeds energy directly into the grid. This energy may be shared by a residential or commercial building before or after the revenue measurement point, depending on whether the credited energy production is calculated independently of the customer's energy consumption (feed-in tariff) or only on the difference of energy (net metering). These systems vary in size from residential (2–10 kWp) to solar power stations (up to 10s of MWp). This is a form of decentralized electricity generation. Feeding electricity into the grid requires the transformation of DC into AC by a special, synchronising grid-tie inverter. In kilowatt-sized installations the DC side system voltage is as high as permitted (typically 1000 V except US residential 600 V) to limit ohmic losses. Most modules (60 or 72 crystalline silicon cells) generate 160 W to 300 W at 36 volts. It is sometimes necessary or desirable to connect the modules partially in parallel rather than all in series. An individual set of modules connected in series is known as a 'string'.
Scale of system.
Photovoltaic systems are generally categorized into three distinct market segments: residential rooftop, commercial rooftop, and ground-mount utility-scale systems. Their capacities range from a few kilowatts to hundreds of megawatts. A typical residential system is around 10 kilowatts and mounted on a sloped roof, while commercial systems may reach a megawatt-scale and are generally installed on low-slope or even flat roofs. Although rooftop mounted systems are small and have a higher cost per watt than large utility-scale installations, they account for the largest share in the market. There is, however, a growing trend towards bigger utility-scale power plants, especially in the "sunbelt" region of the planet.
Performance.
Uncertainties in revenue over time relate mostly to the evaluation of the solar resource and to the performance of the system itself. In the best of cases, uncertainties are typically 4% for year-to-year climate variability, 5% for solar resource estimation (in a horizontal plane), 3% for estimation of irradiation in the plane of the array, 3% for power rating of modules, 2% for losses due to dirt and soiling, 1.5% for losses due to snow, and 5% for other sources of error. Identifying and reacting to manageable losses is critical for revenue and O&M efficiency. Monitoring of array performance may be part of contractual agreements between the array owner, the builder, and the utility purchasing the energy produced. A method to create "synthetic days" using readily available weather data and verification using the Open Solar Outdoors Test Field make it possible to predict photovoltaic systems performance with high degrees of accuracy. This method can be used to then determine loss mechanisms on a local scale - such as those from snow or the effects of surface coatings (e.g. hydrophobic or hydrophilic) on soiling or snow losses. (Although in heavy snow environments with severe ground interference can result in annual losses from snow of 30%.)
Access to the Internet has allowed a further improvement in energy monitoring and communication. Dedicated systems are available from a number of vendors. For solar PV systems that use microinverters (panel-level DC to AC conversion), module power data is automatically provided. Some systems allow setting performance alerts that trigger phone/email/text warnings when limits are reached. These solutions provide data for the system owner and the installer. Installers are able to remotely monitor multiple installations, and see at-a-glance the status of their entire installed base.
Components.
A photovoltaic system for residential, commercial, or industrial energy supply consists of the solar array and a number of components often summarized as the balance of system (BOS). This term is synonymous with "Balance of plant" q.v. BOS-components include power-conditioning equipment and structures for mounting, typically one or more DC to AC power converters, also known as inverters, an energy storage device, a racking system that supports the solar array, electrical wiring and interconnections, and mounting for other components.
Optionally, a balance of system may include any or all of the following: renewable energy credit revenue-grade meter, maximum power point tracker (MPPT), battery system and charger, GPS solar tracker, energy management software, solar irradiance sensors, anemometer, or task-specific accessories designed to meet specialized requirements for a system owner. In addition, a CPV system requires optical lenses or mirrors and sometimes a cooling system.
The terms "solar array" and "PV system" are often incorrectly used interchangeably, despite the fact that the solar array does not encompass the entire system. Moreover, "solar panel" is often used as a synonym for "solar module", although a panel consists of a string of several modules. The term "solar system" is also an often used misnomer for a PV system.
Solar array.
The building blocks of a photovoltaic system are solar cells. A solar cell is the electrical device that can directly convert photons energy into electricity. There are three technological generations of solar cells: the first generation (1G) of crystalline silicon cells (c-Si), the second generation (2G) of thin-film cells (such as CdTe, CIGS, Amorphous Silicon, and GaAs), and the third generation (3G) of organic, dye-sensitized, Perovskite and multijunction cells.
Conventional c-Si solar cells, normally wired in series, are encapsulated in a solar module to protect them from the weather. The module consists of a tempered glass as cover, a soft and flexible encapsulant, a rear backsheet made of a weathering and fire-resistant material and an aluminium frame around the outer edge. Electrically connected and mounted on a supporting structure, solar modules build a string of modules, often called solar panel. A solar array consists of one or many such panels. A photovoltaic array, or solar array, is a linked collection of solar modules. The power that one module can produce is seldom enough to meet requirements of a home or a business, so the modules are linked together to form an array. Most PV arrays use an inverter to convert the DC power produced by the modules into alternating current that can power lights, motors, and other loads. The modules in a PV array are usually first connected in series to obtain the desired voltage; the individual strings are then connected in parallel to allow the system to produce more current. Solar panels are typically measured under STC (standard test conditions) or PTC (PVUSA test conditions), in watts. Typical panel ratings range from less than 100 watts to over 400 watts. The array rating consists of a summation of the panel ratings, in watts, kilowatts, or megawatts.
Module and efficiency.
A typical 150 watt PV module is about a square meter in size. Such a module may be expected to produce 0.75 kilowatt-hour (kWh) every day, on average, after taking into account the weather and the latitude, for an insolation of 5 sun hours/day. Module output and life degraded by increased temperature. Allowing ambient air to flow over, and if possible behind, PV modules reduces this problem. Effective module lives are typically 25 years or more. The payback period for an investment in a PV solar installation varies greatly and is typically less useful than a calculation of return on investment. While it is typically calculated to be between 10 and 20 years, the financial payback period can be far shorter with incentives.
The temperature effect on photovoltaic modules is usually quantified by means of some coefficients relating the variations of the open‐circuit voltage, of the short‐circuit current, and of the maximum power to temperature changes. In this paper, comprehensive experimental guidelines to estimate the temperature coefficients.
Due to the low voltage of an individual solar cell (typically ca. 0.5V), several cells are wired "(also see copper used in PV systems)" in series in the manufacture of a "laminate". The laminate is assembled into a protective weatherproof enclosure, thus making a photovoltaic module or solar panel. Modules may then be strung together into a photovoltaic array. In 2012, solar panels available for consumers have an efficiency of up to about 17%, while commercially available panels can go as far as 27%. It has been recorded that a group from The Fraunhofer Institute for Solar Energy Systems have created a cell that can reach 44.7% efficiency, which makes scientists' hopes of reaching the 50% efficiency threshold a lot more feasible.
Shading and dirt.
Photovoltaic cell electrical output is extremely sensitive to shading ("Christmas light effect"). When even a small portion of a cell, module, or array is shaded, with the remainder is in sunlight, the output falls dramatically due to internal 'short-circuiting' (the electrons reversing course through the shaded portion of the p-n junction). If the current drawn from the series string of cells is no greater than the current that can be produced by the shaded cell, the current (and so power) developed by the string is limited. If enough voltage is available from the other cells in a string, current will be forced through the cell by breaking down the junction in the shaded portion. This breakdown voltage in common cells is between 10 and 30 volts. Instead of adding to the power produced by the panel, the shaded cell absorbs power, turning it into heat. Since the reverse voltage of a shaded cell is much greater than the forward voltage of an illuminated cell, one shaded cell can absorb the power of many other cells in the string, disproportionately affecting panel output. For example, a shaded cell may drop 8 volts, instead of adding 0.5 volts, at a particular current level, thereby absorbing the power produced by 16 other cells. It is thus important that a PV installation is not shaded by trees or other obstructions.
Several methods have been developed to determine shading losses from trees to PV systems over both large regions using LiDAR, but also at an individual system level using sketchup.
Most modules have bypass diodes between each cell or string of cells that minimize the effects of shading and only lose the power of the shaded portion of the array. The main job of the bypass diode is to eliminate hot spots that form on cells that can cause further damage to the array, and cause fires.
Sunlight can be absorbed by dust, snow, or other impurities at the surface of the module (collectively referred to as soiling). Soiling reduces the light that strikes the cells, which in turn reduces the power output of the PV system. Soiling losses aggregate over time, and can become large without adequate cleaning. In 2018, the global annual energy loss due to soiling was estimated to at least 3 % - 4 %.
However, soiling losses varies largely from region to region, and within regions.
Maintaining a clean module surface will increase output performance over the life of the PV system. In one study performed in a snow-rich area (Ontario), cleaning flat mounted solar panels after 15 months increased their output by almost 100%. However, 5° tilted arrays were adequately cleaned by rainwater.
In many cases, especially in arid regions, or in locations in close proximity to deserts, roads, industry, or agriculture, regular cleaning of the solar panels is cost-effective. In 2018, the estimated soiling-induced revenue loss was estimated to between 5 and 7 billion euros.
The long‐term reliability of photovoltaic modules is crucial to ensure the technical and economic viability of PV as a successful energy source. The analysis of degradation mechanisms of PV modules is key to ensure current lifetimes exceeding 25 years.
Insolation and energy.
Solar insolation is made up of direct, diffuse, and reflected radiation. The absorption factor of a PV cell is defined as the fraction of incident solar irradiance that is absorbed by the cell. At high noon on a cloudless day at the equator, the power of the sun is about 1 kW/m2, on the Earth's surface, to a plane that is perpendicular to the sun's rays. As such, PV arrays can track the sun through each day to greatly enhance energy collection. However, tracking devices add cost, and require maintenance, so it is more common for PV arrays to have fixed mounts that tilt the array and face solar noon (approximately due south in the Northern Hemisphere or due north in the Southern Hemisphere). The tilt angle, from horizontal, can be varied for season, but if fixed, should be set to give optimal array output during the peak electrical demand portion of a typical year for a stand-alone system. This optimal module tilt angle is not necessarily identical to the tilt angle for maximum annual array energy output. The optimization of the photovoltaic system for a specific environment can be complicated as issues of solar flux, soiling, and snow losses should be taken into effect. In addition, later work has shown that spectral effects can play a role in optimal photovoltaic material selection. For example, the spectral albedo can play a significant role in output depending on the surface around the photovoltaic system and the type of solar cell material. For the weather and latitudes of the United States and Europe, typical insolation ranges from 4 kWh/m2/day in northern climes to 6.5 kWh/m2/day in the sunniest regions. A photovoltaic installation in the northern latitudes of Europe or the United States may expect to produce 1 kWh/m2/day. A typical 1 kW photovoltaic installation in Australia or the southern latitudes of Europe or United States, may produce 3.5–5 kWh per day, dependent on location, orientation, tilt, insolation and other factors. In the Sahara desert, with less cloud cover and a better solar angle, one could ideally obtain closer to 8.3 kWh/m2/day provided the nearly ever present wind would not blow sand onto the units. The area of the Sahara desert is over 9 million km2. 90,600 km2, or about 1%, could generate as much electricity as all of the world's power plants combined.
Mounting.
Modules are assembled into arrays on some kind of mounting system, which may be classified as ground mount, roof mount or pole mount. For solar parks a large rack is mounted on the ground, and the modules mounted on the rack.
For buildings, many different racks have been devised for pitched roofs. For flat roofs, racks, bins and building integrated solutions are used. Solar panel racks mounted on top of poles can be stationary or moving, see Trackers below. Side-of-pole mounts are suitable for situations where a pole has something else mounted at its top, such as a light fixture or an antenna. Pole mounting raises what would otherwise be a ground mounted array above weed shadows and livestock, and may satisfy electrical code requirements regarding inaccessibility of exposed wiring. Pole mounted panels are open to more cooling air on their underside, which increases performance. A multiplicity of pole top racks can be formed into a parking carport or other shade structure. A rack which does not follow the sun from left to right may allow seasonal adjustment up or down.
Cabling.
Due to their outdoor usage, solar cables are designed to be resistant against UV radiation and extremely high temperature fluctuations and are generally unaffected by the weather. Standards specifying the usage of electrical wiring in PV systems include the IEC 60364 by the International Electrotechnical Commission, in section 712 "Solar photovoltaic (PV) power supply systems", the British Standard BS 7671, incorporating regulations relating to microgeneration and photovoltaic systems, and the US UL4703 standard, in subject 4703 "Photovoltaic Wire".
Tracker.
A solar tracking system tilts a solar panel throughout the day. Depending on the type of tracking system, the panel is either aimed directly at the sun or the brightest area of a partly clouded sky. Trackers greatly enhance early morning and late afternoon performance, increasing the total amount of power produced by a system by about 20–25% for a single axis tracker and about 30% or more for a dual axis tracker, depending on latitude.
Trackers are effective in regions that receive a large portion of sunlight directly. In diffuse light (i.e. under cloud or fog), tracking has little or no value. Because most concentrated photovoltaics systems are very sensitive to the sunlight's angle, tracking systems allow them to produce useful power for more than a brief period each day. Tracking systems improve performance for two main reasons. First, when a solar panel is perpendicular to the sunlight, it receives more light on its surface than if it were angled. Second, direct light is used more efficiently than angled light. Special Anti-reflective coatings can improve solar panel efficiency for direct and angled light, somewhat reducing the benefit of tracking.
Trackers and sensors to optimise the performance are often seen as optional, but they can increase viable output by up to 45%. Arrays that approach or exceed one megawatt often use solar trackers. Considering clouds, and the fact that most of the world is not on the equator, and that the sun sets in the evening, the correct measure of solar power is insolation – the average number of kilowatt-hours per square meter per day. For the weather and latitudes of the United States and Europe, typical insolation ranges from 2.26 kWh/m2/day in northern climes to 5.61 kWh/m2/day in the sunniest regions.
For large systems, the energy gained by using tracking systems can outweigh the added complexity. For very large systems, the added maintenance of tracking is a substantial detriment. Tracking is not required for flat panel and low-concentration photovoltaic systems. For high-concentration photovoltaic systems, dual axis tracking is a necessity. Pricing trends affect the balance between adding more stationary solar panels versus having fewer panels that track.
As pricing, reliability and performance of single-axis trackers have improved, the systems have been installed in an increasing percentage of utility-scale projects. According to data from WoodMackenzie/GTM Research, global solar tracker shipments hit a record 14.5 gigawatts in 2017. This represents growth of 32 percent year-over-year, with similar or greater growth projected as large-scale solar deployment accelerates.
Inverter.
Systems designed to deliver alternating current (AC), such as grid-connected applications need an inverter to convert the direct current (DC) from the solar modules to AC. Grid connected inverters must supply AC electricity in sinusoidal form, synchronized to the grid frequency, limit feed in voltage to no higher than the grid voltage and disconnect from the grid if the grid voltage is turned off. Islanding inverters need only produce regulated voltages and frequencies in a sinusoidal waveshape as no synchronisation or co-ordination with grid supplies is required.
A solar inverter may connect to a string of solar panels. In some installations a solar micro-inverter is connected at each solar panel. For safety reasons a circuit breaker is provided both on the AC and DC side to enable maintenance. AC output may be connected through an electricity meter into the public grid. The number of modules in the system determines the total DC watts capable of being generated by the solar array; however, the inverter ultimately governs the amount of AC watts that can be distributed for consumption. For example, a PV system comprising 11 kilowatts DC (kWDC) worth of PV modules, paired with one 10-kilowatt AC (kWAC) inverter, will be limited to the inverter's output of 10 kW. As of 2019, conversion efficiency for state-of-the-art converters reached more than 98 percent. While string inverters are used in residential to medium-sized commercial PV systems, central inverters cover the large commercial and utility-scale market. Market-share for central and string inverters are about 44 percent and 52 percent, respectively, with less than 1 percent for micro-inverters.
Maximum power point tracking (MPPT) is a technique that grid connected inverters use to get the maximum possible power from the photovoltaic array. In order to do so, the inverter's MPPT system digitally samples the solar array's ever changing power output and applies the proper resistance to find the optimal "maximum power point".
Anti-islanding is a protection mechanism to immediately shut down the inverter, preventing it from generating AC power when the connection to the load no longer exists. This happens, for example, in the case of a blackout. Without this protection, the supply line would become an "island" with power surrounded by a "sea" of unpowered lines, as the solar array continues to deliver DC power during the power outage. Islanding is a hazard to utility workers, who may not realize that an AC circuit is still powered, and it may prevent automatic re-connection of devices. Anti-Islanding feature is not required for complete Off-Grid Systems.
Battery.
Although still expensive, PV systems increasingly use rechargeable batteries to store a surplus to be later used at night. Batteries used for grid-storage also stabilize the electrical grid by leveling out peak loads, and play an important role in a smart grid, as they can charge during periods of low demand and feed their stored energy into the grid when demand is high.
Common battery technologies used in today's PV systems include the valve regulated lead-acid battery– a modified version of the conventional lead–acid battery, nickel–cadmium and lithium-ion batteries. Compared to the other types, lead-acid batteries have a shorter lifetime and lower energy density. However, due to their high reliability, low self discharge as well as low investment and maintenance costs, they are currently the predominant technology used in small-scale, residential PV systems, as lithium-ion batteries are still being developed and about 3.5 times as expensive as lead-acid batteries. Furthermore, as storage devices for PV systems are stationary, the lower energy and power density and therefore higher weight of lead-acid batteries are not as critical as, for example, in electric transportation Other rechargeable batteries considered for distributed PV systems include sodium–sulfur and vanadium redox batteries, two prominent types of a molten salt and a flow battery, respectively. In 2015, Tesla Motors launched the Powerwall, a rechargeable lithium-ion battery with the aim to revolutionize energy consumption.
PV systems with an integrated battery solution also need a charge controller, as the varying voltage and current from the solar array requires constant adjustment to prevent damage from overcharging. Basic charge controllers may simply turn the PV panels on and off, or may meter out pulses of energy as needed, a strategy called PWM or pulse-width modulation. More advanced charge controllers will incorporate MPPT logic into their battery charging algorithms. Charge controllers may also divert energy to some purpose other than battery charging. Rather than simply shut off the free PV energy when not needed, a user may choose to heat air or water once the battery is full.
Monitoring and metering.
The metering must be able to accumulate energy units in both directions, or two meters must be used. Many meters accumulate bidirectionally, some systems use two meters, but a unidirectional meter (with detent) will not accumulate energy from any resultant feed into the grid. In some countries, for installations over 30 kWp a frequency and a voltage monitor with disconnection of all phases is required. This is done where more solar power is being generated than can be accommodated by the utility, and the excess can not either be exported or stored. Grid operators historically have needed to provide transmission lines and generation capacity. Now they need to also provide storage. This is normally hydro-storage, but other means of storage are used. Initially storage was used so that baseload generators could operate at full output. With variable renewable energy, storage is needed to allow power generation whenever it is available, and consumption whenever needed.
The two variables a grid operator have are storing electricity for "when" it is needed, or transmitting it to "where" it is needed. If both of those fail, installations over 30kWp can automatically shut down, although in practice all inverters maintain voltage regulation and stop supplying power if the load is inadequate. Grid operators have the option of curtailing excess generation from large systems, although this is more commonly done with wind power than solar power, and results in a substantial loss of revenue. Three-phase inverters have the unique option of supplying reactive power which can be advantageous in matching load requirements.
Photovoltaic systems need to be monitored to detect breakdown and optimize operation. There are several photovoltaic monitoring strategies depending on the output of the installation and its nature. Monitoring can be performed on site or remotely. It can measure production only, retrieve all the data from the inverter or retrieve all of the data from the communicating equipment (probes, meters, etc.). Monitoring tools can be dedicated to supervision only or offer additional functions. Individual inverters and battery charge controllers may include monitoring using manufacturer specific protocols and software. Energy metering of an inverter may be of limited accuracy and not suitable for revenue metering purposes. A third-party data acquisition system can monitor multiple inverters, using the inverter manufacturer's protocols, and also acquire weather-related information. Independent smart meters may measure the total energy production of a PV array system. Separate measures such as satellite image analysis or a solar radiation meter (a pyranometer) can be used to estimate total insolation for comparison.
Data collected from a monitoring system can be displayed remotely over the World Wide Web, such as OSOTF.
Other systems.
This section includes systems that are either highly specialized and uncommon or still an emerging new technology with limited significance. However, standalone or off-grid systems take a special place. They were the most common type of systems during the 1980s and 1990s, when PV technology was still very expensive and a pure niche market of small scale applications. Only in places where no electrical grid was available, they were economically viable. Although new stand-alone systems are still being deployed all around the world, their contribution to the overall installed photovoltaic capacity is decreasing. In Europe, off-grid systems account for 1 percent of installed capacity. In the United States, they account for about 10 percent. Off-grid systems are still common in Australia and South Korea, and in many developing countries.
CPV.
Concentrator photovoltaics (CPV) and "high concentrator photovoltaic" (HCPV) systems use optical lenses or curved mirrors to concentrate sunlight onto small but highly efficient solar cells. Besides concentrating optics, CPV systems sometime use solar trackers and cooling systems and are more expensive.
Especially HCPV systems are best suited in location with high solar irradiance, concentrating sunlight up to 400 times or more, with efficiencies of 24–28 percent, exceeding those of regular systems. Various designs of systems are commercially available but not very common. However, ongoing research and development is taking place.
CPV is often confused with CSP (concentrated solar power) that does not use photovoltaics. Both technologies favor locations that receive much sunlight and are directly competing with each other.
Hybrid.
A hybrid system combines PV with other forms of generation, usually a diesel generator. Biogas is also used. The other form of generation may be a type able to modulate power output as a function of demand. However more than one renewable form of energy may be used e.g. wind. The photovoltaic power generation serves to reduce the consumption of non renewable fuel. Hybrid systems are most often found on islands. Pellworm island in Germany and Kythnos island in Greece are notable examples (both are combined with wind). The Kythnos plant has reduced diesel consumption by 11.2%.
In 2015, a case-study conducted in seven countries concluded that in all cases generating costs can be reduced by hybridising mini-grids and isolated grids. However, financing costs for such hybrids are crucial and largely depend on the ownership structure of the power plant. While cost reductions for state-owned utilities can be significant, the study also identified economic benefits to be insignificant or even negative for non-public utilities, such as independent power producers.
There has also been work showing that the PV penetration limit can be increased by deploying a distributed network of PV+CHP hybrid systems in the U.S. The temporal distribution of solar flux, electrical and heating requirements for representative U.S. single family residences were analyzed and the results clearly show that hybridizing CHP with PV can enable additional PV deployment above what is possible with a conventional centralized electric generation system. This theory was reconfirmed with numerical simulations using per second solar flux data to determine that the necessary battery backup to provide for such a hybrid system is possible with relatively small and inexpensive battery systems. In addition, large PV+CHP systems are possible for institutional buildings, which again provide back up for intermittent PV and reduce CHP runtime.
Floating solar arrays.
Floating solar arrays are PV systems that float on the surface of drinking water reservoirs, quarry lakes, irrigation canals or remediation and tailing ponds. These systems are called "floatovoltaics" when used only for electrical production or "aquavoltaics" when such systems are used to synergistically enhance aquaculture. A small number of such systems exist in France, India, Japan, South Korea, the United Kingdom, Singapore and the United States.
The systems are said to have advantages over photovoltaics on land. The cost of land is more expensive, and there are fewer rules and regulations for structures built on bodies of water not used for recreation. Unlike most land-based solar plants, floating arrays can be unobtrusive because they are hidden from public view. They achieve higher efficiencies than PV panels on land, because water cools the panels. The panels have a special coating to prevent rust or corrosion.
In May 2008, the Far Niente Winery in Oakville, California, pioneered the world's first floatovoltaic system by installing 994 solar PV modules with a total capacity of 477 kW onto 130 pontoons and floating them on the winery's irrigation pond. The primary benefit of such a system is that it avoids the need to sacrifice valuable land area that could be used for another purpose. In the case of the Far Niente Winery, it saved that would have been required for a land-based system. Another benefit of a floatovoltaic system is that the panels are kept at a cooler temperature than they would be on land, leading to a higher efficiency of solar energy conversion. The floating PV array also reduces the amount of water lost through evaporation and inhibits the growth of algae.
Utility-scale floating PV farms are starting to be built. The multinational electronics and ceramics manufacturer Kyocera will develop the world's largest, a 13.4 MW farm on the reservoir above Yamakura Dam in Chiba Prefecture using 50,000 solar panels. Salt-water resistant floating farms are also being considered for ocean use, with experiments in Thailand. The largest so far announced floatovoltaic project is a 350 MW power station in the Amazon region of Brazil.
Direct current grid.
DC grids are found in electric powered transport: railways trams and trolleybuses. A few pilot plants for such applications have been built, such as the tram depots in Hannover Leinhausen, using photovoltaic contributors and Geneva (Bachet de Pesay). The 150 kWp Geneva site feeds 600 V DC directly into the tram/trolleybus electricity network whereas before it provided about 15% of the electricity at its opening in 1999.
Standalone.
A stand-alone or off-grid system is not connected to the electrical grid. Standalone systems vary widely in size and application from wristwatches or calculators to remote buildings or spacecraft. If the load is to be supplied independently of solar insolation, the generated power is stored and buffered with a battery. In non-portable applications where weight is not an issue, such as in buildings, lead acid batteries are most commonly used for their low cost and tolerance for abuse.
A charge controller may be incorporated in the system to avoid battery damage by excessive charging or discharging. It may also help to optimize production from the solar array using a maximum power point tracking technique (MPPT). However, in simple PV systems where the PV module voltage is matched to the battery voltage, the use of MPPT electronics is generally considered unnecessary, since the battery voltage is stable enough to provide near-maximum power collection from the PV module.
In small devices (e.g. calculators, parking meters) only direct current (DC) is consumed. In larger systems (e.g. buildings, remote water pumps) AC is usually required. To convert the DC from the modules or batteries into AC, an inverter is used.
In agricultural settings, the array may be used to directly power DC pumps, without the need for an inverter. In remote settings such as mountainous areas, islands, or other places where a power grid is unavailable, solar arrays can be used as the sole source of electricity, usually by charging a storage battery. Stand-alone systems closely relate to microgeneration and distributed generation.
Costs and economy.
The cost of producing photovotaic cells has dropped because of economies of scale in production and technological advances in manufacturing. For large-scale installations, prices below $1.00 per watt were common by 2012. A price decrease of 50% had been achieved in Europe from 2006 to 2011 and there is a potential to lower the generation cost by 50% by 2020. Crystal silicon solar cells have largely been replaced by less expensive multicrystalline silicon solar cells, and thin film silicon solar cells have also been developed at lower costs of production. Although they are reduced in energy conversion efficiency from single crystalline "siwafers", they are also much easier to produce at comparably lower costs.
The table below shows the total (average) cost in US cents per kWh of electricity generated by a photovoltaic system. The row headings on the left show the total cost, per peak kilowatt (kWp), of a photovoltaic installation. Photovoltaic system costs have been declining and in Germany, for example, were reported to have fallen to USD 1389/kWp by the end of 2014. The column headings across the top refer to the annual energy output in kWh expected from each installed kWp. This varies by geographic region because the average insolation depends on the average cloudiness and the thickness of atmosphere traversed by the sunlight. It also depends on the path of the sun relative to the panel and the horizon.
Panels are usually mounted at an angle based on latitude, and often they are adjusted seasonally to meet the changing solar declination. Solar tracking can also be utilized to access even more perpendicular sunlight, thereby raising the total energy output.
The calculated values in the table reflect the total (average) cost in cents per kWh produced. They assume a 10% total capital cost (for instance 4% interest rate, 1% operating and maintenance cost, and depreciation of the capital outlay over 20 years). Normally, photovoltaic modules have a 25-year warranty.
System cost 2013.
In its 2014 edition of the "Technology Roadmap: Solar Photovoltaic Energy" report, the International Energy Agency (IEA) published prices in US$ per watt for residential, commercial and utility-scale PV systems for eight major markets in 2013.
Learning curve.
Photovoltaic systems demonstrate a learning curve in terms of levelized cost of electricity (LCOE), reducing its cost per kWh by 32.6% for every doubling of capacity. From the data of LCOE and cumulative installed capacity from International Renewable Energy Agency (IRENA) from 2010 to 2017, the learning curve equation for photovoltaic systems is given as
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Regulation.
Standardization.
Increasing use of photovoltaic systems and integration of photovoltaic power into existing structures and techniques of supply and distribution increases the need for general standards and definitions for photovoltaic components and systems. The standards are compiled at the International Electrotechnical Commission (IEC) and apply to efficiency, durability and safety of cells, modules, simulation programs, plug connectors and cables, mounting systems, overall efficiency of inverters etc.
National regulations.
In the UK, PV installations are generally considered permitted development and don't require planning permission. If the property is listed or in a designated area (National Park, Area of Outstanding Natural Beauty, Site of Special Scientific Interest or Norfolk Broads) then planning permission is required.
In the United States, article 690 of the National Electric Code provides general guidelines for the installation of photovoltaic systems; these may be superseded by local laws and regulations. Often a permit is required necessitating plan submissions and structural calculations before work may begin. Additionally, many locales require the work to be performed under the guidance of a licensed electrician.
In the United States, the Authority Having Jurisdiction (AHJ) will review designs and issue permits, before construction can lawfully begin. Electrical installation practices must comply with standards set forth within the National Electrical Code (NEC) and be inspected by the AHJ to ensure compliance with building code, electrical code, and fire safety code. Jurisdictions may require that equipment has been tested, certified, listed, and labeled by at least one of the Nationally Recognized Testing Laboratories (NRTL). . In the US, many localities require a permit to install a photovoltaic system. A grid-tied system normally requires a licensed electrician to connect between the system and the grid-connected wiring of the building. Installers who meet these qualifications are located in almost every state. Several states prohibit homeowners' associations from restricting solar devices.
Although Spain generates around 40% of its electricity via photovoltaic and other renewable energy sources, and cities such as Huelva and Seville boast nearly 3,000 hours of sunshine per year, in 2013 Spain issued a solar tax to account for the debt created by the investment done by the Spanish government. Those who do not connect to the grid can face up to a fine of 30 million euros (US$40 million). Such measures were finally withdrawn by 2018, when new legislation was introduced banning any taxes on renewable energy self-consumption.
Limitations.
Pollution and energy in PV production.
PV has been a well-known method of generating clean, emission free electricity. PV systems are often made of PV modules and inverter (changing DC to AC). PV modules are mainly made of PV cells, which has no fundamental difference to the material for making computer chips. The process of producing PV cells (computer chips) is energy intensive and involves highly poisonous and environmental toxic chemicals. There are few PV manufacturing plants around the world producing PV modules with energy produced from PV. This measure greatly reduces the carbon footprint during the manufacturing process. Managing the chemicals used in the manufacturing process is subject to the factories' local laws and regulations.
Impact on electricity network.
With the increasing levels of rooftop photovoltaic systems, the energy flow becomes 2-way. When there is more local generation than consumption, electricity is exported to the grid. However, electricity network traditionally is not designed to deal with the 2- way energy transfer. Therefore, some technical issues may occur. For example, in Queensland Australia, there have been more than 30% of households with rooftop PV by the end of 2017. The famous Californian 2020 duck curve appears very often for a lot of communities from 2015 onwards. An over-voltage issue may come out as the electricity flows back to the network. There are solutions to manage the over voltage issue, such as regulating PV inverter power factor, new voltage and energy control equipment at electricity distributor level, re-conductor the electricity wires, demand side management, etc. There are often limitations and costs related to these solutions.
Implication onto electricity bill management and energy investment.
Customers have different specific situations, e.g. different comfort/convenience needs, different electricity tariffs, or different usage patterns. An electricity tariff may have a few elements, such as daily access and metering charge, energy charge (based on kWh, MWh) or peak demand charge (e.g. a price for the highest 30min energy consumption in a month). PV is a promising option for reducing energy charge when electricity price is reasonably high and continuously increasing, such as in Australia and Germany. However, for sites with peak demand charge in place, PV may be less attractive if peak demands mostly occur in the late afternoon to early evening, for example residential communities. Overall, energy investment is largely an economic decision and investment decisions are based on systematical evaluation of options in operational improvement, energy efficiency, onsite generation and energy storage.


Tyco connector


Solar power in Washington, D.C.

Solar power in Washington, D.C. has been growing in recent years due to new technological improvements and a variety of regulatory actions and financial incentives, especially a 30% tax credit, which has been extended with a phase down approach. A bill signed on Dec 18, 2015 extends the 30% Solar Investment Tax Credits for both residential and commercial projects through the end of 2019, and then drops the credit to 26% in 2020, and 22% in 2021 before dropping permanently to 10% for commercial projects and 0% for residential projects. Washington, D.C. has the potential to install 2,100 MW of rooftop photovoltaics using technology available in 2012, which would generate 21% of the electricity used in 2010.
Every two years a Solar Decathlon is held on the National Mall. Contestants are challenged to build an energy efficient building that is capable of generating all of the energy used. In 2013 the Solar Decathlon was held outside Washington, D.C. for the first time, and was located in Orange County.
The Mount Pleasant Solar Cooperative and DC SUN.
In 2006 Mount Pleasant residents Anya Schoolman and George Musser's sons Walter and Diego had watched Al Gore's documentary, An Inconvenient Truth and suggested that their families do something about the climate change problem. Upon investigating the possibility of going solar, Schoolman found the problems of building code, financial and contracting issues too complex to be solved by a single person, so Schoolman, Musser and their two sons formed the Mount Pleasant Solar Cooperative to bring greater time, expertise, lobbying and buying power to the problem. In 2009 45 houses in Mount Pleasant went solar. Since then that number has grown to about 250. Soon a Capitol Hill Solar Co-op was calling seeking Mount Pleasant's expertise. Eventually there were solar coops in every ward in the District. In 2010 the eleven neighborhood solar coops of Washington, DC formed an umbrella organization, DC Solar United Neighborhoods (DC SUN). The SUN model has begun spreading to additional states, including Maryland and Virginia. In 2011, Schoolman founded the Solar United Neighbors (then called Community Power Network), a nonprofit organization bringing together the efforts of local renewable energy groups. As of May 2019, Solar United Neighbors is active in 12 U.S States.
Anya Schoolman and the Mount Pleasant Solar Cooperative were the subject of a segment in M. Sanjayan's Discovery Channel series, "Powering The Future" and have been recognized by the White House's Champions of Change program.
Availability.
Insolation is good at about 4.7 sun hours/day.


Summit Power

Summit Power Group is a Seattle-based energy development company, responsible for developing electric power plants and other energy-related facilities, which are primarily natural gas-fired and wind-powered, with solar power recently added. Summit does not develop conventional coal-fired power plants without carbon capture. Summit's prospective IGCC/CCS projects include the Texas Clean Energy Project, the Renewable Energy Corporation Project in Montana, and surface facilities for underground coal gasification (UCG) projects in the early stages of development by Laurus Energy as a licensee of Ergo Exergy.