Determination of Optimal Solar Power and Corresponding Tilted Angle in Different Geoclimatic Zones in Nigeria

Aims: To estimate the optimum tilt angle and maximum solar power for different geoclimatic zones in Nigeria.

Methodology: In this study, the surface data of direct and diffuse solar radiations spanning 2013 to 2017 were obtained from the archives of the Modern-Era Retrospective Analysis for Research and Application for 20 stations spread across Nigeria. To study the direct relationship between the solar power on a photovoltaic panel and the solar radiation, the values of the direct, diffuse, and ground-reflected components of solar radiation were calculated for six tilt angles ranging from 15° to 90° using anisotropic models. Afterwards, the maximum values of the solar power and the corresponding tilt angles, as well as the average number of solar panels that can be used to cater for the electricity needs of households in all the geoclimatic zones, were estimated.

Results: Analyses showed that the maximum solar power was received at tilt angles of 30° and 45° from October till February, and tilt angles of 15° and 30° from March till September in all the study locations. For instance, the Sahel and Guinea Savanna zones had the highest solar power, whereas Derived Savanna and Coastal zones had relatively low power. Based on the results, it was determined that the number of solar panels required in the sahel zone would be lower than those of the other zones.

Conclusion: It can be inferred from the results that the reception of maximum solar power is at the tilt angle of 45o in Sahel, Guinea, and Derived Savanah regions, and at 30o in the Coastal region. The results of this research will provide solar engineers with accurate information on the orientation and tilt of PV modules for efficient power generation.