Impact of cooling uniformity on the thermal and electrical performance of photovoltaic-thermal systems: A three-dimensional numerical study

Abstract

This study presents a three-dimensional numerical analysis to compare the performance of a fully cooled photovoltaic thermal system (PVT-S) with that of a partially cooled system. The aim is to highlight the impact of temperature inhomogeneity on PVT-S performance. The influence of solar irradiance, between 700 and 1100 W/m 2 , on system performance was also studied, representing operating conditions typical of hot climates and potential building-integrated PVT applications. The numerical analysis was performed utilizing COMSOL Multiphysics, which employs the finite element method (FEM), and the results were verified against previously published data. The results show that the completely cooled system achieves electrical and thermal efficiencies of 13.37% and 65.40% respectively, while the partially cooled system achieves efficiencies of 12.43% and 52.91%. Furthermore, increasing solar irradiation from 700 to 1100 W/m 2 leads to an increase in cell temperature and electrical output, with values of 13.45°C and 62.17 W for the partially cooled system, compared with 5.69°C and 76.25 W for the completely cooled system. These findings demonstrate the potential of complete cooling to improve PVT performance under high-temperature operating conditions, although practical implementation must consider additional costs, design complexity, and installation constraints.