THE CAPACITY FACTOR AS A MEASURE OF THE EFFICIENCY OF THE WIND POWER PLANT

Abstract

The article studies the properties of utilization of installed capacity (the capacity factor) , used as a criterion for the efficiency of wind turbines. Usually it means that the increase of the capacity factor provides increased turbine performance over time in accordance with the formula . иум К T QВЭУ = TKиумWуст The article reveals and examines the factors that determine the wind turbines performance depending on the properties of the wind energy potential of specific areas and the parameters that are formed in the design of wind turbines. The influence of the rated wind speed Vp on the wind turbine performance has been considered. It is shown that an increase in the value of rated wind speed Vp increases the wind power plant performance. On the base of empirical probability density function the maximum value of the coefficient Киум (VG ,Vp ) has been determined as a function of the average wind speed and the magnitude of the rated wind speed. It is shown that the coefficient value is substantially dependent on the average annual wind speed . Therefore, an indication of its particular value must be accompanied by an indication of the mean annual wind speed . иум К VG VG It is shown that an increase in the rated wind speed, which is accompanied by an increase in turbine performance reduces the capacity factor Киум (Vp ) . At the same time the highest value of the capacity factor , which is achieved at the rated wind speed , corresponds to the wind turbines performance equal zero. иум К = 1 Vp = 0 Identified properties of the capacity factor contradict to the task of increasing the wind turbines performance. Therefore, when designing wind turbines, the task of increasing of the capacity factor cannot be the goal. The capacity factor cannot be used as a criterion for the effectiveness of the design of wind turbines. Influence of factors, that increase the wind turbines performance, is adequately reflected in the coefficient of wind power potential utilization , introduced in article.