Modeling and Experimental Investigation of PV Module Thermal Behavior Based on Energy Balance through Its Different Layers

An increase in operating temperature of the crystalline photovoltaic modules (PVMs) has a significant impact on their electrical efficiency. Accurate determination of this parameter is crucial for a credible evaluation of PVM performance. Due to the difficulty of analytically solving the energy balance equations (EBEs) to determine the temperature profile of the various layers of the PVM, numerical solutions are often chosen. The exact analytical solution of these equations is challenging to achieve due to the complexity of some time-dependent parameters (solar irradiance, ambient temperature, wind speed, front and rear surface temperatures, …) and can only be reached in particular cases. To overcome this difficulty, some approximations are considered and permit the resolution of this problem analytically. In this study, a one-dimensional model is developed. It is based on an analytical solution of the steady-state EBEs. The analytical solution is reached by assuming that the time-varying parameters can be considered constant over more or less long time intervals, depending on the change rate of these parameters. The objective of this study is to propose an analytical model improving the prediction accuracy of the temporal and spatial evolution of the PVM operating temperature compared with literature results; meanwhile, simplifying the estimation process of the various photovoltaic system parameters. The experimental and modeling results obtained are compared with those evaluated using other relevant models. The compatibility between the experimental and model results attests to the reliability of the assumed approximations, with regard to calculated RMSE (0.78) and MBE (0.77) values.