Characterization of wind speed data according to wind direction

Knowledge of the wind speed distribution and the most frequent wind directi ons is important when choosing wind turbines and when locating them. For th is reason wind evaluation and characterization are important when forecasti ng output power. The data used here were collected from eleven meteorologic al stations distributed in Navarre, Spain. We obtained data for the period extending from 1992 to 1995, with each datum encompassing 10 minutes of tim e. Wind speed data of each station were gathered in eight directional secto rs, each one extended over 45 degrees according to the direction from which the wind blows. The stations were grouped in two blocks: those under the i nfluence of the Ebro valley and those in mountainous areas. For each group the Weibull parameters were estimated, (according to the Weibull probabilit y paper because the Weibull distribution gives the best fit in this region) . Kurtosis and skewness coefficients were estimated as well. The Weibull pa rameters, especially the scale parameter c, depend strongly on the directio n considered, and both Weibull parameters show an increasing trend as the d irection considered moves to the more dominant direction, while both kurtos is and skewness show a corresponding decreasing trend. (C) 1999 Elsevier Sc ience Ltd. All rights reserved.