Investigation of an air-cooled double-channel photovoltaic/thermal system with integrated thermal energy storage

Abstract

The performance of photovoltaic cells is severely limited by increasing internal temperatures within the solar cells. It is crucial to either remove or store the excess thermal energy from the solar cells to improve energy efficiency. To address this, a Phase Change Material (PCM) has been integrated into an air-cooled double-channel photovoltaic/thermal (PV/T) system. This model has been established to analyze the effects of the PCMs' thermophysical properties, the height ratio of upper/lower channels, the thickness of the PCMs layer, and the air mass flow rate on the thermal performance of the system. The numerical model has been validated with maximum errors of 5.90% and 4.40% for the PV panel and air outlet temperature, respectively. The results show that the height ratio of the upper and lower channels has a significant impact on the system's performance, with a height ratio of 0.25 achieving the highest performance of 66.2%. It is found that RT22HC shows the highest overall performance among the four paraffin waxes (melting range: 17–29 °C). Additionally, it is found that a 15 mm PCM layer achieves the optimum performance of 70.5%. Finally, the correlation between air mass flow rate and enhanced electrical and thermal efficiency are also discussed. The study provides valuable insights into optimizing the PV/T system's performance, contributing to advancements in solar energy utilization.