Assessment of wind speed variation pattern and estimation of wind power density in Calabar, Nigeria – A. E. Akpan, O. O. Akinpelu, R. C. Okoro, A. I. Menkiti
Five years wind speed data have been analysed and used to estimate Weibull parameters for Calabar, Nigeria. Results show that monthly wind speeds usually vary from 1-7 m/s at a hub height of 100 m. 5 years modal and average wind speeds, v are 4.26 and 3.36 m/s respectively. Seasonal changes exert significant influence on wind speed in the area. February and March, which are the peak months of the dry season, have highest v of 3.92 and 4.00 m/s respectively. May and November, which are the seasonal transitional months, are characterized by low wind speeds with v of 2.74 m/s. Weibull parameters estimated using graphical and power density procedures revealed good correlation. Values of the shape parameter, k vary from 2.82 m/s in 2007, which has the lowest annual v of 2.98 m/s, to 4.41 m/s in 2006, which has the highest annual v of 3.78 m/s. Mean values of the scale parameter, c ranges between 2.90 m/s in 2007 to 3.80 m/s in 2006. The Weibull distribution curves are nearly Gaussian (except for 2007) although the skew of the data fluctuates between positive (+1.14 in 2005) and negative (-0.34 in 2009) sides of the mean. Wind power density vary from 4.36 W/m2 in February, 2007 to 63.49 W/m2 in September. 2007. Therefore only lowly rated wind power systems with cut-in speed of ~2 m/s can function normally in the area.