VIABILITY OF WIND ENERGY AS A POWER GENERATION SOURCE IN FIVE SELECTED CITIES OF SOUTH WESTERN NIGERIA

Abstract

In this study, the wind speed characteristics and energy potential in five selected locations in the southwestern part of Nigeria which are Abeokuta, Akure, Ikeja, Osogbo and Ibadan were investigated using monthly mean wind speed data of 51 years (1961 - 2011) obtained from the Nigeria Meteorological Agency. The specific objectives of the study are to evaluate the possibility of generating power from the wind regime in the cities and to determine the economic viability of doing so. The data were subjected to the 2-parameter-Weibull and other statistical analyses and the equivalent wind at 80 m height was also evaluated and the magnitude of electrical power output simulated at this height from three practical turbine models (GE 1.5xle, AV 927 and AV 928). The study also analysed the econometrics of wind electricity generation at the five cities from the three wind turbine models. The outcome showed that the wind speed measured at a height of 10 m ranged from 1.3 to 13.2 m/s while the wind speed at 80 m ranges from 2.6 to 24.5 m/s. The modal wind speed at 10 m ranges from 3.0 to 5.9 m/s while the modal wind speed at 80 m ranges from 7.0 to 8.5 m/s. It was also found that 83.6% of the data were of wind speed greater than 3.0 m/s, which is the cut in speed of many modern turbines. The average monthly wind speed ranged from 2.72 to 7.72 m/s. Seasonally, average wind speeds ranged between 3.47 to 6.55 m/s and 3.83 to 6.94 m/s for dry (October to March) and wet (April to September) seasons, respectively. The two parameters of the Weibull statistics, the shape (k) and scale (c) were found to lie between 2.99 ≤ k ≤ 5.32 and 3.02 ≤ c ≤ 8.57, respectively. The annual mean power densities are 65.09, 145.07, 176.96, 387.07 and 87.34 W/m2 for Abeokuta, Akure, Ibadan, Ikeja and Osogbo respectively. It was further shown that the respective annual mean value of the most probable wind speed are 3.82, 4.97, 5.23, 7.03 and 4.01 m/s, while the annual mean values of the wind speed carrying maximum energy are 4.12, 5.48, 5.87, 7.50 and 4.55 m/s. Results showed that potential exist for electricity generation of between 0.3 and 1.6 GWh per month and between 1.5 and 16.8 GWh per annum. It 3 was also discovered that better potential exist for wind power generation in the wet season (0.3 - 1.7GWh) than in the dry season (0.2 – 1.5GWh). The minimum cost of generating 1kWh of wind electricity with the turbine models at the cities was estimated to be N2.32 with a maximum cost of N29.80 and it was observed that this is more cost efficient than the conventional power supply based on a 2012 presidential taskforce report on the real cost of electricity in Nigeria. The study therefore concluded that it was potentially and economically viable to generate electricity from wind from these cities using the appropriate wind turbines.