Performance indicators for offshore wind farms

The drive for alternative energy sources has resulted in many proposals for offshore wind farms in the United Sates. Offshore wind turbines are subject to harsh environmental conditions including but not limited to simultaneous action of extreme wind and wave loading as well as hurricanes. From a structural reliability point of view, there are several failure mechanisms of a wind turbine such as blade or other component fatigue, tower local or global buckling and foundation failure such as sliding. In addition, there are several mechanical components and a control mechanism that could be studied from a traditional reliability point of view. Given the complexity of the problem which involves a combination of structural and electromechanical systems, an approach based on annual power generation is considered here to evaluate the performance of offshore wind farms. © ASCE 2011