Energy efficiency and performance analysis of cooling solar energy systems

This study investigated the effects of a passive water cooling method to mitigate temperature-induced efficiency losses in photovoltaic (PV) panels in hot climates. Two polycrystalline PV panels with identical characteristics were used; the reference panel was left uncooled, while the other panel was cooled by water circulating through finned aluminum pipes integrated into its rear surface. The experiments were conducted under Iskenderun climate conditions on three different dates (June 25, September 20, and October 2); the first experiment was run under a constant load, while the other two were performed near maximum power point (MPP) conditions. Experimental measurements showed that the surface temperature of the cooled panel was, on average, 10–14°C lower than the reference panel across all experiments. This temperature reduction resulted in an increase in power generation of 9,2% in June, 10,44% with MPP tracking in September, and 5,8% in October due to lower irradiation conditions. The cooling effect was particularly pronounced between the hours of 12:00 and 15:00, with the power difference ranging from 7% to 11%. Furthermore, the heating of the outlet water confirmed that effective heat was being drawn from the panel surface. The results indicate that water-based passive cooling is an effective, economical, and viable method for increasing the efficiency of PV panels in hot regions. It is concluded that the method will make a significant contribution to PV applications, especially in areas experiencing high irradiation and high ambient temperatures.