Cooling of PV Panels with Earth–Air Heat Exchanger and Novelly Designed Plenums: An Experimental Study

Abstract Photovoltaic (PV) panels convert solar radiation into both electrical and thermal energy; however, their principal objective is the generation of electricity. Elevated surface temperatures adversely affect electrical output and efficiency, thereby necessitating the development of effective cooling strategies and methods. In the present study, an experimental investigation was conducted in Şanlıurfa, Türkiye, characterized by a hot and arid climate. An air-cooled PV system was integrated with an earth–air heat exchanger (EAHX), and two novel rear-side plenum configurations (Design 1 and Design 2) were developed and tested under real environmental conditions. The performance of the system was assessed using both EAHX air and direct ambient air for cooling. The experimental results demonstrate that the integration of EAHX air yields substantial performance improvements compared with the uncooled reference panel. Specifically, electrical efficiency increased by 9.70% with EAHX cooling and by 4.30% with ambient air cooling. Correspondingly, the mean surface temperature reductions were 15 and 7.96 °C, respectively. Among the proposed configurations, Design 1—a six-wing plenum—exhibited superior thermal regulation performance. Furthermore, the analysis revealed that cooling under low solar irradiance (< 500 W/m 2 ) provided negligible improvements in both electrical output and surface temperature reduction. Overall, the findings confirm that coupling PV panels with EAHX-assisted plenum structures is more effective than conventional ambient air cooling and can serve as a promising approach to enhance PV performance in regions with extreme climatic conditions.