Maximizing solar photovoltaic efficiency with Mist Cooled sandwich bifacial panels under extreme hot climate conditions

Abstract

A novel sandwich bifacial photovoltaic panel system with integrated mist cooling is proposed to enhance energy generation per unit area in photovoltaic installations. Traditional bifacial photovoltaic panels effectively utilize ground reflections. Still, they often encounter high operating temperatures, leading to thermal degradation. This new design features a back-to-back arrangement of two mono-facial photovoltaic panels, incorporating mist cooling between them. This innovative design significantly increases energy density while effectively mitigating thermal degradation. Experimental investigations were conducted under actual outdoor conditions representative of extremely hot climates, with the United Arab Emirates chosen as a specific case study. The experimental results show that the energy yield from the sandwich bifacial photovoltaic panel was 26.05 % higher than that of a standard monofacial photovoltaic panel operating without cooling. For the rear-facing photovoltaic surface temperature, a reduction of 34.03 % is observed for the front surface, and 14.81 % is recorded for the rear surface with mist cooling. The corresponding temperature reduction for the front-facing panel was 20.48 % on a sunny day and 13.18 % on a cloudy day, and the reduction in the rear surface was 9.61 % and 16.02 %, respectively. Such thermal enhancements are expected to yield power gains of 37.14 % on sunny days and 46.02 % on cloudy summer days compared to conventional mono-facial photovoltaic panels. The system demonstrated an annual energy output of 45.34 kWh/m² more than mono-facial systems, corresponding to an annual economic gain of $5.48/m². This approach represents one very efficient and practical way to improve the photovoltaic performance without compromising the already-occupied ground surface.