Mini-channel heat sink design for solar photovoltaic cooling: Experimental evaluation and performance metrics

Effective thermal management in photovoltaic (PV) systems is key to preserving energy efficiency and extending panel lifespan. This study aims to improve PV thermal regulation by introducing a patented S-mini-channel heat sink (SMCHS) designed to overcome fluid maldistribution challenges common in traditional PV cooling configurations. The proposed system consists of 53 minichannels integrated with a triangular header and lateral inlet/outlet design, intending to promote uniform flow distribution under varying operating conditions. On the one hand, experimental results demonstrate significant cooling performance, with surface temperature reductions of 21.48 °C (front) and 35.39 °C (rear) under 800 W/m² solar radiation. The change led to a 1.17 % improvement in electrical efficiency (from 11.42 % to 12.5 %) and a 9.43 % increase in power output, equivalent to a gain of 1.89 W. Additionally, a 4 °C temperature rise in the coolant at a flow rate of 4 L/min confirmed the system's effective heat transfer capacity. On the other hand, a three-dimensional conjugate heat transfer numerical model was validated against the experimental measurements and employed to reinforce flow behavior analyze. The numerical simulations confirmed that an optimal outlet velocity of 0.217 m/s results in a uniform velocity profile across all minichannels, with an average flow velocity of 0.031 m/s per channel. Thus, the SMCHS design ensures consistent thermal performance, enhances energy conversion, and offers promising potential for industrial applications in next-generation PV systems and solar thermal technologies.