Performance Study of Nano-Enhanced PCM in Building-Integrated Semi-Transparent Photovoltaic Modules

Buildings account for nearly 40% of global energy consumption, mainly due to the demands of artificial lighting and heating, ventilation, and air-conditioning (HVAC) systems. The integration of semi-transparent photovoltaic (STPV) modules into building envelopes presents a sustainable strategy to lower energy use while simultaneously replacing conventional roofs and façades. However, the performance of STPV systems is strongly influenced by incident solar radiation and building orientation, and elevated surface temperatures can further diminish their efficiency. In this study, the performance of an STPV module was assessed by placing it on a horizontal surface and varying its orientation relative to a 90° reference. To mitigate thermal effects and improve efficiency, a thermal management system incorporating a calcium chloride hexahydrate-based phase change material (PCM) was employed. The PCM was enhanced with nanomaterials—graphene oxide (GO) and aluminum oxide (Al2O3)—at weight fractions of 0%, 0.25%, 0.5%, and 1%. The thermophysical properties of the nano-enhanced PCM were analyzed using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and thermal conductivity measurements. Under incident solar radiation of 941 W/m2, the electrical efficiencies of the PV, PV–PCM1, and PV–PCM2 modules were measured at 13.75%, 16.84%, and 15.28%, respectively, demonstrating the potential of nano-enhanced PCM to improve STPV performance.