Abstract
High temperatures significantly degrade the performance of photovoltaic (PV) panels, particularly in hot regions. To mitigate this issue, hybrid PV/thermal systems have emerged, combining PV panels with thermal collectors. These systems utilize a cooling fluid to remove excess heat from the PV panels, improving their efficiency and enabling the recovery of thermal energy. This study investigates the potential of nanofluids as a superior cooling medium for hybrid PV/thermal systems. Nanofluids, engineered suspensions of nanoparticles in base fluids, offer enhanced thermal properties compared to conventional fluids. A numerical analysis using the finite volume method (FVM) based on Ansys software / CFD fluent was conducted to simulate the performance of a hybrid PV/thermal system under hot weather conditions. The study focused on natural convection cooling, eliminating the need for pumps and reducing energy consumption. Results indicate that decreasing the inlet velocity of the nanofluid significantly reduced the surface temperature of the PV panels. A reduction in inlet velocity to 0.0001 m/s led to a 4.5 K decrease in surface temperature, while a velocity of 0.00005 m/s resulted in a 6 K decrease. Conversely, the temperature of the nanofluid outlet increased by 16 K and 30 K for the respective velocities, signifying enhanced heat extraction. These findings demonstrate that optimizing the flow rate of the nanofluid can significantly improve the electrical and thermal performance of hybrid PV/thermal systems. This research contributes to the development of more efficient and sustainable solar energy technologies.

Key words: Coolant, Efficiency, Nanofluid, CFD, Photovoltaic cell.