Advanced Heat Sink Fin Design: A Study on Geometric Parameters and Their Influence on Convective Heat Transfer for Double Pass Solar Photovoltaic Thermal (PVT)

A photovoltaic–thermal (PVT) collector is a hybrid system capable of generating electrical and thermal energy simultaneously. However, the efficiency of photovoltaic (PV) modules decreases as operating temperature increases, which limits overall system performance. This study focuses on enhancing the performance of a PVT system by integrating a heat sink fin collector with improved geometrical designs. The proposed heat sink has dimensions of 400 × 400 mm with a 10 mm edge spacing and a fin length of 5 cm, incorporating repeating fin patterns to maximize heat dissipation. By increasing the surface area, the heat sink absorbs excess heat from the PV module, reducing its operating temperature and improving electrical efficiency while enabling useful thermal energy recovery. Five different fin designs were developed and evaluated using computational fluid dynamics (CFD) analysis under airflow of 2 m/s to 10 m/s with solar irradiance between 600 W/m2 to 100W/m2. Both electrical and thermal efficiencies were analyzed and compared to identify the most effective design. The results show that Design 1 achieved the highest overall efficiency, with efficiency ranging from 49.02% to 66.58% under constant irradiance of 100W/m2. The photovoltaic efficiency obtained was 13.3% while thermal efficiency exceeded 53% at the highest flow rate. Furthermore, increasing airflow velocity reduces the PV temperature from 43 ˚C to 30 ˚C which helps to improve the electrical performance. The findings conclude that the optimum heat sink geometry significantly improve heat transfer and overall performance of the double pass PVT system.