Analytical Model for the Wind Farm Capacity Factor Based on Local Wind Characteristics

An important parameter to quantitatively assess the performance of a wind farm is its capacity factor. This study presents an analytical model to determine the capacity factor of a wind farm using the Weibull probability distribution function according to the local wind speed associated with the characteristics of the selected wind turbine. The model is based on the analytical integral of the wind energy characteristics calculated in relation to the wind speed probability distribution. The model allows determining the best rated speed for the wind turbine considering the local wind characteristic. The study has also introduced an analytical method for the wind turbine selection in order to maximize the plant’s capacity factor. In addition, the model allows determining the turbine operating time in each of the regions of the power curve. Knowing the distribution of operating time is useful for formulating failure monitoring strategies and operation and maintenance (O&M) planning. The proposed model has been validated by experimental results obtained in a wind farm in Southern Brazil.