IEC 61400 is an international standard published by the International Electrotechnical Commission (IEC) regarding wind turbines. Purpose and function IEC 61400 is a set of design requirements made to ensure that wind turbines are appropriately engineered against damage from hazards within the planned lifetime. The standard concerns most aspects of the turbine life from site conditions before construction, to turbine components being tested, assembled and operated. Wind turbines are capital intensive, and are usually purchased before they are being erected and commissioned. Some of these standards provide technical conditions verifiable by an independent, third party, and as such are necessary in order to make business agreements so wind turbines can be financed and erected. IEC started standardizing international certification on the subject in 1995, and the first standard appeared in 2001. The common set of standards sometimes replace the various national standards, forming a basis for global certification. Small wind turbines are defined as being of up to 200 m2 swept area and a somewhat simplified IEC 61400-2 standard addresses these. It is also possible to use the IEC 61400-1 standard for turbines of less than 200 m2 swept area. The standards for loads and noise are used in the development of prototypes at the Østerild Wind Turbine Test Field. Harmonization In the U.S., standards are intended to be compatible with IEC standards, and some parts of 61400 are required documentation. The U.S. National Renewable Energy Laboratory participates in IEC standards development work, and tests equipment according to these standards. For U.S. offshore turbines however, more standards are needed, and the most important are : ISO 19900, General requirements for offshore structures ISO 19902, Fixed steel offshore structures ISO 19903, Fixed concrete offshore structures ISO 19904-1, Floating offshore structures – mono-hulls, semisubmersibles and spars ISO 19904-2, Floating offshore structures - tension-leg platforms API RP 2A-WSD, Recommended practice for planning, designing and constructing fixed offshore steel platforms - working stress design. In Canada, the previous national standards were outdated and impeded the wind industry, and they were updated and harmonized with 61400 by the Canadian Standards Association with several modifications. An update for IEC 61400 is scheduled for 2016. For small wind turbines the global industry has been working towards harmonisation of certification requirements with a "test once, certify everywhere" objective. Considerable co-operation has been taking place between UK, USA, and more recently Japan, Denmark and other countries so that the