Investigating the optimal Photovoltaic (PV) tilt angle using the Photovoltaic Geographic Information System (PVGIS)

Abstract

This work presents an investigation of the optimal tilt angles for mounting pv panels in South –South and South - East States in Nigeria when no tracking system exists using the photovoltaic geographic information system (PVGIS). Experiments were carried out to verify results obtained from the PVGIS database. The experimental set up consist of five PV panels each rated 10Watts inclined at five different angles including the optimal angle obtained from the PVGIS database. South-South Nigeria consists of six states (Rivers, Delta, Bayelsa, Edo, Cross-Rivers and Akwa-Ibom). South-East Nigeria consists of five states (Abia, Enugu, Imo, Ebonyi and Anambra). The optimal installation angle of selected cities within each of the States was identified. Results from experiments conducted showed that from January to April and September to December, the yearly optimal tilt angle (11o for Port Harcourt, 12o for Yenagoa, 11o for Benin City, 10o for Calabar, 11o for Asaba and 10o for Uyo) is suitable for use in the South – South while from January to April and September to December, the yearly optimal tilt angle (10o for Umuahia, 11o for Awka, 12o for Enugu, 10o for Owerri, and 11o for Abakaliki) is suitable for use in the South – East. The horizontal plane (0o ) is suitable from May to August in both South – South and South – Eastern States. The untapped solar potential in the South – South was observed to be as high as 286.62kWh/m2 for Port Harcourt and a low value of 19.34kWh/m2 was recorded in Calabar when solar panels are not installed at the optimal angles. For the South –East, the untapped solar potential was observed to be as high as 222.11kWh/m2 for Umuahia and a lowest value of 21.31kWh/m2 was also recorded in Umuahia when solar panels were not installed at the optimal angles. Installing PV panels at the optimal tilt angle can improve the efficiency of solar energy generation, making it more cost-effective by maximizing the total amount of diffused and direct radiation.