Forecasting solar power output in Ibadan: A machine learning approach leveraging weather data and system specifications
Accurate solar irradiance forecasting is critical for solar power planning and grid stability in tropical monsoon regions like Ibadan, Nigeria, yet conventional methods suffer from high dependency on expensive ground-based pyranometers. Method: This study proposes a physics-informed, data-driven two-stage irradiance forecasting framework. Stage one integrates clear-sky models with cloud-type classification to improve hourly global horizontal (GHI), direct normal (DNI), and diffuse horizontal (DHI) irradiance predictions. Stage two employs PVLib to estimate photovoltaic power output using meteorological inputs, cloud conditions, and system-specific parameters. Random forest, CNN, and LSTM models are comparatively evaluated. Contribution/Results: Random forest achieves the best performance, yielding annual normalized root-mean-square errors (nRMSE) of 0.19 (GHI), 0.33 (DNI), and 0.22 (DHI); during the dry season, GHI nRMSE drops to 0.12. The framework significantly reduces reliance on ground measurements and offers a scalable, low-cost solution for high-accuracy solar forecasting in tropical monsoon climates.