Dew-point evaporative cooling of PV panels for improved performance

Abstract

Solar energy is an important energy source for a sustainable future. The advancements of solar cells for electricity production require improvements in the cooling technology. Conventional air cooling is not able to cool the photovoltaic (PV) panels effectively. On the other hand, dew-point evaporative cooling (DPEC) can bring down the inlet air temperature below its wet bulb which makes itself an excellent candidate for PV cooling. In this work, a novel cooling configuration that consists of two wet channels: one in the cooler (conventional DPEC) to produce the pre-cooled supply air and the other at the back of the PV panel, was proposed. A physics-based mathematical model utilizing local weather conditions was developed for the system to investigate its transient performance. The cooling performance and subsequent improvement in the PV’s energy efficiency of the proposed system were compared with a traditional DPEC-based cooling approach. It was observed that the proposed system can maintain an efficiency of more than 15% (with 16.7% maximum) under two environmental conditions in summer, which is an increase of 16.4% compared to air cooling. The proposed PV cooling method will help to improve the overall performance of the solar PV systems and increase renewable energy utilizations.