Power calculation accuracy as a function of wind data resolution

Abstract

Wind power calculations are usually based on average wind data taken over one-hour intervals. The effect of the wind data resolution on the statistical techniques used to calculate the probable power output (PPO) is commonly overlooked. This effect is analysed in this paper by iteratively calculating and comparing the PPO of a wind turbine using data, averaged over different periods, obtained from Wind Association of South Africa. The power is calculated using both Weibull representation and direct polynomial substitution techniques in order to compare and verify the results. The results indicate a fairly linear relationship between the resolution used and the PPO error incurred. These results raise an interest to examine the effects of a fine resolution on the data in terms of data dependence, which may violate the criteria for the majority of statistical tests and procedures.