A Statistical Analysis of Wind Distribution and Wind Power Potential in the Coastal Region of South Africa

Abstract

This article investigates the wind characteristics and the wind power potential for electricity generation in the coastal regions of South Africa through the analysis of local wind regime of ten different sites. The data used consist of 10-min average time series wind speeds, temperatures, and standard deviation measured at anemometer height of 20 and 60 m for a period of 1 year. First, the statistical distribution model that best fits the empirical wind speed data in the areas of study is determined based on the coefficient of determination and root mean square error, which are used to test the goodness of fit. The parameters and the wind power density based on this model are estimated for each of the months and season of the year. For a realistic result in estimating the power density, the stochastic nature of the site air density based on the local temperature and the site altitude above the sea level is taken into consideration. The diurnal (day and night), electricity peak periods wind characteristic, and the turbulence intensity of the sites are calculated. The optimum wind speed, most probable wind speed and shear exponential which are important pieces of information in the selection of wind turbines are evaluated. Some of the key results show that at 60 m anemometer height, site WM05 has an exceptional wind power potential with annual power density of 694 W/m², while site WM02 shows a poor wind power potential with annual power density of 216.29 W/m².

Keywords:

• South Africa
• Statistical analysis
• Weibull distribution
• Wind power potential

ACKNOWLEDGMENTS

The authors acknowledge the financial support of the Tshwane University of Technology. We also thank the Department of Energy (DoE), UNDP-GEF through South African Wind Energy Programme (SAWEP), and the Royal Danish Embassy for their initiative on Wind Atlas for South African Project and making the wind speed data available through CSIR.