Experimental Investigation of the Effect of Seasonal Variation on Photovoltaic Panel Output in Maiduguri

Solar photovoltaic systems are increasingly deployed for off-grid electrification in northeastern Nigeria, yet performance data under local seasonal conditions remain limited. This study investigates how seasonal variation affects the output power, fill factor, and efficiency of a 100-watt monocrystalline photovoltaic panel installed at the University of Maiduguri campus in Borno State, North East Nigeria. Daily measurements of open-circuit voltage, short-circuit current, module temperature, and ambient irradiance were recorded over a complete annual cycle spanning wet and dry seasons. Output power was measured under standard test conditions using a solar power analyzer, with corrections applied for measured deviations from standard irradiance. Statistical analysis using ANOVA was applied to determine whether seasonal differences in output parameters were statistically significant. Results indicate a 27 percent reduction in peak power output during the wet season compared to the harmattan dry season, attributed primarily to increased cloud cover and atmospheric particulate loading during sandstorms. Module temperature was found to correlate inversely with efficiency, with each degree Celsius increase above 25 degrees Celsius reducing efficiency by approximately 0.45 percent. The study provides empirically grounded performance benchmarks for photovoltaic system sizing in northeastern Nigeria. Recommendations for dust cleaning protocols and tilt angle optimization are provided. Keywords: photovoltaic, seasonal variation, Maiduguri, solar energy, module efficiency