Abstract

Weibull distribution is often invoked to interpret and predict wind characteristics needed for effective design of wind power systems for different locations. In this paper, daily average wind data for Enugu (6.4°N; 7.5°E), Onitsha (6.8°N; 6.1°E) and Owerri (5.5°N; 7.0°E) over a 25-year period is modeled in terms of the Weibull distribution in order to accurately predict wind potentials for the locations. The monthly and annual wind speed probability density distributions at 10 m meteorological height were analyzed and the Weibull shape and scale factors were empirically determined for the locations. The predicted and measured wind speed probability density distributions of the locations are compared and the accuracy of the model determined for each location using Pearson product moment correlation coefficient (r) and root-mean-square error (ξ). We find r and ξ to be 0.64, 1.40, 0.67, 1.17 and 0.93, 1.55, respectively, for Enugu, Onitsha and Owerri. The results suggest that the model can be used, with acceptable accuracy, for predicting wind energy output needed for preliminary design assessment of wind machines for the locations.

Key words: Renewable energy-general, wind, Weibull distribution.