Integrate of night radiative cooling technology using a photovoltaic thermal collector under three different climates

Abstract

This work examines the performance of the combination of night radiative cooling with solar thermal and photovoltaic technologies under three different climates using a PV/T collector. It also proposes the use of radiative cooling technology as a method for enhancing the temperature and electrical efficiency of PV cells of the same PV/T collector. It has been mathematically realized based on the equations governing heat transfer in the collector and the finite difference method. The developed model has been experimentally validated and used to achieve the proposed aims. The main results show first that the highest electrical, thermal, and cooling powers were obtained in the hot arid climate, because of the solar radiation and air temperature at day, as well as the sky temperature at night of this climate. While the minimum ones were obtained in the Mediterranean hot summer climate and precisely the cooling power which was very low due to the high relative humidity. Finally, the use of night radiative cooling technology has allowed reducing the PV cells temperature by 2-7 °C and 2-6 °C during 8 hours in the arid and semi-arid climates, respectively, which has enhanced the electrical efficiency of the used collector.

Keywords

• PV/T collector
• Night radiative cooling
• Numerical model
• Electrical performance
• Finite differential method