Optimization of Photovoltaic Tilt Angles for Maximum Solar Energy Harvesting in a Tropical Savanna Region

The optimization of photovoltaic systems for sustainable energy generation is crucial for reducing reliance on fossil fuels and addressing the growing demand for electricity. In this study, we determined the optimum tilt angle for maximizing solar radiation capture in Kogi State, Nigeria, an area characterized as a tropical savanna region. Mathematical modeling using Excel and Matlab (ExMod and MatMod) are employed to analyze global, beam, and diffuse radiation components based on Nigerian Meteorological Agency (NiMET) data. Key parameters such as clearness index, daylight hours, and sunset angles were evaluated across five tilt angles (0^◦, 7.8^◦, 22.8^◦, 37.8^◦, and 52.8^◦). Results show that 7.8^◦ (Kogi’s latitude) is the optimal fixed tilt angle, balancing beam and diffuse radiation for year-round performance, while seasonal adjustments (e.g., 22.8^◦ in dry months, 52.8^◦ in wet months) further enhance energy yield. The clearness index peaks at 0.53 in the dry season (November—December) but drops to 0.33 in the rainy season (July—August), with stable daylight hours (11—12.4 h/day) ensuring consistent solar potential. The study recommends fixed 7.8^◦ systems for cost-effective deployment and adjustable angles for seasonal optimization, providing critical insights for PV system design in tropical climates.