Numerical investigation of passive cooling strategies for photovoltaic modules using recycled polyurethane foam and aluminum fins

This work presents a numerical study of two passive cooling strategies for photovoltaic (PV) modules using recycled materials. The main goal is to limit the performance losses caused by high operating temperatures under real outdoor conditions, which differ significantly from Standard Test Conditions (STC), and to improve the overall electrical efficiency. The analysis is performed using three-dimensional transient simulations in COMSOL Multiphysics, coupling heat transfer and fluid flow in solid and porous domains. In the first configuration, a recycled polyurethane (PU) foam layer saturated with water is applied at the rear of the PV module to enhance heat dissipation through coupled heat and moisture transport within the porous structure, including evaporative cooling effects. The second configuration uses aluminum fins attached to the rear surface of the module, increasing the heat exchange area and strengthening natural convection with ambient air. The results show that the PU foam and aluminum fin systems reduce the average operating temperature by 16.4 °C and 9.8 °C, respectively, compared with the reference module. These reductions translate into relative electrical efficiency improvements of 8.49% and 5.10%, confirming the effectiveness of both passive cooling approaches under the studied conditions.