Experimental investigation on performance comparison of PV/T-PCM system and PV/T system

Photovoltaic/thermal (PV/T) panels are devices commonly used for the conversion of solar energy into heat and electricity. The use of phase change materials (PCMs) can efficiently decrease the temperature of a PV module; this is a critical factor influencing the energy efficiency of a PV/T system. First, experiments were conducted to compare the overall energy efficiencies of the PV/T-PCM and PV/T systems. By measuring the power output, backplane temperature, and tank water temperature, the thermal, electrical, and primary energy-saving efficiencies of the two systems were calculated. The integration of a PCM layer into a PV/T panel was found to effectively reduce its heat loss to ambient. The heat stored into the PCM can be discharged into the working fluid when the solar radiation is less intensive or unavailable; this can extend its service time to the targeted building. Under a controlled indoor environment with a radiation of 800 W/m2 and water flow rate of 0.15 m3/h, the primary energy-saving efficiency for the PV/T-PCM system increased by 14%. These results indicate that the integration of a PCM into a PV/T system can obviously improve the energy performance of the system.