SUMMARY

Wind power is the fasting growing technology for producing electricity in both the United States and the world. In 2005 installed capacity in the U.S. grew from 6718 to 9149 megawatts—an annual increase of 36% percent. Increases in 2006 are projected to be even larger. As it is a relatively young industry, a great deal of optimization work needs to be done. This study analyzed the optimal relationship between rotor and generator size at a series of wind resources using varying capital cost constraints. It is well documented that winds at a given site follow the Weibull probability distribution function. A Weibull distribution for a given wind site can be completely defined by two parameters, average wind speed and a probability shape parameter. In the study, a model was developed to predict the annual electrical energy output of wind turbines with given design characteristics at wind resources defined by the Weibull parameters. The wind resource Weibull parameters were then varied to determine the optimum relationship of rotor to generator size. The figure of merit was defined as annual electrical energy produced for a given capital cost. The optimization parameter was rotor size per peak generator capacity. The final product is a series of graphs that show the effect each of the variables has on the optimized design, and graphs that show the optimum rotor size for a given generator for varying wind resources.