Photovoltaic evaporative chimney as a new alternative to enhance solar cooling

Abstract

Cooling sector plays a crucial role in the World's transition towards an efficient and decarbonised energy system. Solar cooling is an attractive idea because of the chronological coincidence between available solar radiation and cooling needs. This paper studies the possibility of increasing the efficiency of solar photovoltaic modules by evaporative cooling. This, combined with the use of a water condensed chiller, will enable an efficient cooling system design as a whole. To achieve this goal this paper experimentally evaluates the thermal and electrical performance of a Photovoltaic Evaporative Chimney. A prototype with two photovoltaic modules was built; one of them is used as a reference and the other is modified in its rear side including the evaporative solar chimney. The system is able to dissipate a thermal power of about 1500 W with a thermal efficiency exceeding 30% in summer conditions. The module temperature differences reach 8 K, depending on the wind conditions and ambient air psychrometric properties. Regarding the electrical efficiency, the results showed an average improvement of 4.9% to a maximum of 7.6% around midday in a typical summer day for a Mediterranean climate.