Efficiency Enhancement of Photovoltaic Thermal System by Using Solar Collector: An Experimental Examination

• Outdoor experimental comparison of PV and spiral-tube PVT configurations. • Fabrication and integration of RT-42 PCM and graphene-based nano-PCM layer. • Measured PV back-surface temperature, coolant temperatures, and irradiance profiles. • Quantified electrical, thermal, and overall efficiencies under identical conditions. • Demonstrated improved thermal regulation and performance stability using nano PCM. The current world is gradually focusing on utilization of renewable energy technologies, especially photovoltaic (PV) systems. As temperature of panel increases, the efficiency of PV decreases, therefore, temperature must be maintained to achieve optimum efficiency. Efficient thermal control is required to maximize performance and prolong the lifetime of PV modules. This study presents a new design in a counter flow spiral mechanism of fluid flow and Nano Phase Change Materials (nano-PCM) to provide uniform temperature distribution across PV cells. Simple PV and PVT (Photovoltaic thermal) with absorber configuration and with nano-PCM are experimented. It has been found that the flow rate of 0.48 l/min can be increased to 2.4 l/min and the tube diameter of 10mm to 15mm to improve electrical efficiency up to 13.6% and lower module temperature by 8.2 °C. This design is not only capable of holding equal temperatures among the modules but also makes significant improvements of about 3.2% and 22.5% in electrical and thermal efficiencies respectively. The nano-PCM experimentally tested at a thickness of 25mm provides the heat retention in the PCM. According to the results of experiments, the electrical efficiency of PV and PVT is 70% and 90% respectively. The thermal efficiency is improved and reaches a high of 83% at an irradiance of 900 W/m 2 . These developments indicate that such a design has the potential of increasing the efficiency and sustainability of solar energy systems.