Fast and Physically Constrained Modelling of Solar PV Power Output Using an Optimized Ordinary Differential Equation (ODE) Framework
Olusegun A. Olaiju
Department of Mathematics and Statistics, Federal Polytechnic Ilaro, Nigeria.
Olumuyiwa A. Agbolade
Department of Mathematics and Statistics, Federal Polytechnic Ilaro, Nigeria.
Ephesus O. Fatunmbi *
Department of Mathematics and Statistics, Federal Polytechnic Ilaro, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
This study develops and validates a physically informed ordinary differential equation (ODE) model for predicting photovoltaic (PV) power output under varying environmental conditions. The proposed framework couples panel thermal dynamics with temperature-dependent electrical efficiency while incorporating multiple environmental forcing variables, including solar irradiance, ambient temperature, wind speed, humidity, and atmospheric pressure. Unknown physical parameters are estimated through bounded optimization using the L-BFGS-B algorithm, ensuring thermodynamic consistency and physically realistic parameter values. The model is validated using real-world hourly operational data from a grid-connected PV system. Results demonstrate strong predictive performance with R² = 0.9824, RMSE = 20.98 W, and MAE = 11.32 W, indicating that the model captures more than 98% of the variance in observed power output. Monte Carlo simulations confirm model robustness under typical sensor noise conditions, producing narrow uncertainty bounds around predicted trajectories. The proposed framework provides a computationally efficient and physically interpretable alternative to purely data-driven forecasting approaches, making it suitable for real-time PV monitoring, forecasting, and grid integration applications.
Keywords: Photovoltaic power prediction, ordinary differential equations, physics-informed modelling, thermal dynamics, parameter optimization, renewable energy forecasting, energy system modelling