A study is being carried out by Holland Windturbine B.V. concerning the economics of wind power plants. Detailed analyses are made of the costs and energy production of wind turbines. From these analyses optimum turbine parameters are derived. The efficiency of the plant as well as the additional cost of the plant are also subjects of analysis. With the results of these sub-studies economic parameters of plants like energy cost and pay-back time can be assessed and optimized.