Analysis of Solar Irradiance Data and Its Correlation with Photovoltaic Output in Sokoto State

Background: Sokoto State in North West Nigeria receives among the highest annual solar radiation levels on the continent, making it ideal for photovoltaic energy generation. Systematic irradiance-output correlation studies are needed to support system design. Aim: This study analysed solar irradiance data and its correlation with photovoltaic panel output in Sokoto State. Methods: Daily global horizontal irradiance data were obtained from the Nigerian Meteorological Agency for a 24-month period. A 250W polycrystalline PV panel installed at a fixed tilt of 12 degrees south was monitored using a data acquisition system recording power output at 15-minute intervals. Pearson correlation and linear regression were applied in analysis. Results: Mean annual global horizontal irradiance in Sokoto was 6.48 kWh/m2/day. A strong positive correlation (r = 0.91) was found between daily irradiance and PV output. Panel efficiency declined by approximately 0.45% per degree Celsius above the standard test condition temperature. Seasonal dust accumulation reduced output by 11% in the dry season without cleaning. Conclusion: Sokoto State's high and predictable irradiance makes it highly suitable for utility-scale PV deployment. Regular panel cleaning schedules and temperature derating factors should be incorporated into system design guidelines for North West Nigeria. Keywords: solar irradiance, photovoltaic, Sokoto, energy generation, correlation analysis.