Thermal management performance of finned photovoltaic/phase change material systems with thermal storage stepped enclosures

The temperature rise of photovoltaic (PV) panels leads to a reduction in their electrical efficiency, and the use of phase change material (PCM) for PV thermal regulation is currently a widely adopted approach. This work proposes a novel stepped cavity structure for PV/PCM systems and integrates it with fins to achieve effective thermal management of PV panels. The results of implemented numerical simulations indicate that, compared with the rectangular cavity, the adoption of a stepped cavity structure extends the flow path of the PCM, enhances the natural convection in the upper part of the cavity, and improves the heat dissipation performance between the system back plate and the environment. Specifically, relative to the pure rectangular cavity, it can reduce the average temperature of the silicon layer by a maximum of 3.20 K. Within stepped-cavity configurations, the incorporation of fins suppresses large-scale liquid phase PCM vortices while simultaneously enhancing heat conduction from the PV panel to the solid PCM. Compared with the pure rectangular cavity, this coupling can reduce the mean silicon layer temperature by up to 5.07 K. Moreover, by tailoring both cavity geometry and fin topology, a maximum reduction of 12.5% in mean temperature uniformity is attainable compared with the rectangular baseline cavity.