Estimation of Wind Power Potential of Six Sites in Eastern Cape Province of South Africa

Aims: To use the five year wind speed measurements to assess the wind power potential of six sites of part of the Eastern Cape Province.

Study Design: The potential for generating electricity from wind was assessed for six sites of the western part of the Eastern Cape Province (Bisho, Fort Beaufort, Graaff – Reinet, Grahamstown, Port Elizabeth and Queenstown)

Place and Duration of Study: The study was carried out at University of Fort Hare, South Africa between June and December 2014.

Methodology: The five-year-long, hourly average wind speed series between January 2009 and December 2013 for the six Eastern Cape weather stations were obtained from South African Weather Services (SAWS). The data was statistically analysed using the Weibull distribution function in MATLAB.

Results: The dimensionless Weibull shape parameter, k, varied from 1.7 to 2.2, while the scale parameter, c, varied between 3.5 and 6.3 connected power generation while an average of 3 ms-1 to 4 ms-1. The most probable wind speed, vmp, expected in the province ranged from 2.1 to 4.1 connected power generation while an average of 3 ms-1 to 4 ms-1. The wind power densities ranged from 34.7 to 207.8 Wm-2. The annual Weibull probability density frequency curves vary from site to site, in both its shape and maximum value and are all skewed towards lower wind velocities except for Port Elizabeth

Conclusion: Basing on the American Wind Energy Association (AWEA) classification, Fort Beaufort, Graaff– Reinet and Queenstown correspond to wind power class 1 while Bisho and Grahamstown correspond to class 2. Consequently they are not suitable for installation of large turbines for grid connection. Nevertheless, they are suitable for stand-alone systems. Port Elizabeth corresponds to class 4 and hence is suitable for grid connected applications. It is thus recommended to install large turbines for grid connected applications in Port Elizabeth and small scale wind turbines for stand-alone applications such as supplying power to individual houses and irrigation in Bisho, Fort Beaufort, Graaff – Reinet, Grahamstown and Queenstown.