THE FEASIBILITY STUDY OF WIND POWER GENERTION OVER ARBAMINCH, ETHIOPIA

As the conventional energy sources are quickly depleting all over the globe, there is an imminent need to explore and exploit the possibilities of other alternative energy sources. With this back drop wind energy appears to be a potential resource as it is abundantly and cheaply available at all places. As the wind is a vector, it offers a force that has the potential to generate kinetic energy. The technology for converting this kinetic energy of wind is already globally well known and it is also relatively sustainable and environment friendly.

The wind data measured by National Meteorological Agency (NMA) of Ethiopia, through Automatic Weather Station during the period 1987 to 2012 (25 years) at Arbaminch Station located in Arbaminch University campus was utilized for the present analysis. While the annual and seasonal variability of wind run was examined, the variability of kinetic energy and power was computed and presented.

The average monthly variation of wind during the period 1987 to 2012 show a minimum value of 0.41 ms-1 during November and a maximum value of 0.80 ms-1 during August. The monthly kinetic energy also varies in the same way with a minimum value of 0.10 joules during November and maximum of 0.39 joules during August as it is proportional to wind. The average annual wind run during the period 1987 to 2012 shows the variability with a minimum of 0.21 ms-1during 2012 and a maximum value of 0.88 ms-1 during 2004. The average annual variability of kinetic energy has a minimum of 0.03 joules during 2012 and a maximum of 0.80 joules during 1988 which is in corroboration with the wind run values. The monthly average power output (Horse Power) works out to nearly three and half times of the energy output which is about 0.74 watts. When compared with the variability in maximum values during the period of 1987 to 2012, the year 1988 recorded a maximum value of 0.80 joules, while 2009 recorded a low of 0.35 joules.

The extreme variability of wind in some years was observed due to the impact of global climatological forcings like ENSO and IOD.

Total nine months in kiremt (June to August), Belg season (March to May) and spring (September-November) together in Arbaminch area are favorable for tapping wind energy as mean surface wind speeds of the order of 0.82 ms-1 at the surface with the output energy of 0.41 joules and wind power of about 1.02 KW is available. This wind comes to greater than 4 m s-1 in the upper level above 100 meters in the outskirts of the city area over the mountains for which the wind power works out to be equal to 118.40 Kilo watts.