Hybrid photovoltaic-thermal system using phase change material: A comparative numerical study of fin designs

Solar photovoltaic (PV) technologies have gained prominence due to the escalating global energy demand and the environmental impact associated with fossil fuels. Nevertheless, elevated operating temperatures significantly reduce PV system performance, necessitating effective thermal control. This study introduces a hybrid PV-thermal (PVT) system that integrates phase change material (PCM) alongside various fin configurations, including flat, zigzag, and wavy, to enhance electrical efficiency and facilitate thermal energy recovery. A 3D transient model in COMSOL Multiphysics was developed to simulate heat transfer, phase change, and temperature regulation driven by PV under constant solar irradiance. Compared with other designs, the results show that zigzag fins increase PCM melting by more than 15%, achieving the highest thermal energy extraction rate of 54.42 kW per 1 kg/s of water flow. Conversely, wavy fins sustain the lowest surface temperature of the PV system, yielding the highest electrical efficiency (11.65%). The analysis reveals a significant trade-off between optimizing heat recovery and enhancing PV production, indicating that the choice of fin geometry must align with specific energy-application goals. These findings highlight the potential for personalized PVT-PCM combinations to enhance the thermal efficiency of building-integrated solar energy systems.