Variation of Solar Radiation in Akwanga, Nasarawa State, Nigeria

One of the major environmental problem is the long-term changes in the Earth’s climate. In this study, the variation of solar radiation for Akwanga zone, Nasarawa State, Nigeria were determined. Twelve locations were carefully selected where there is no sunshine and wind obstruction. Three 12V, 5W Solar panels (poly) were used and a three-hour daily measurement interval (12.00 pm to 3.00 pm) was made using the Secondary Standard Pyranometer placed on the top of the panels. Angstrom-Prescott Regression Equation was used to estimate the output. The continuity in the assembled system was measured using an Avometer. The result revealed that the highest monthly average daily global solar radiation was observed in the month of April (25.2 MJ/m2) followed by June (22.94 MJ/m2), and march (22.42 MJ/m2), while the lowest was observed in the month of August (12.04 MJ/m2) followed by July (13.57 MJ/m2), and September (14.26 MJ/m2) in the locations selected. The solar radiation intensity was found to range from 156.44 W/m2 to 293.84 W/m2 with the mean value of 220.04 W/m2. The highest total global solar radiation value of 25.2MJ/m2 was observed in April while the lowest value of 12.04 MJ/m2 was observed in October. The extraterrestrial solar radiation were found to range from 16.72 MJ/m2 in March to 29.90 MJ/m2 in April with average value of 22.89MJ/m2. The atmospheric transmission coefficient over the year is found to range from 0.5 in July and October to 1.3 in June and October. The investigation reveal that there is bright sun shine in the study area which confirms high atmospheric transmission coefficient or clearness index throughout the year in this study.