Evaporative cooling of photovoltaic panels in dry and hot climatic conditions

Abstract

ABSTRACT Solar photovoltaic (PV) technology is a popular choice among other renewable energy sources, but its electrical efficiency decreases with a rise in PV panel temperature. Previous studies on passive cooling with phase change material (PCM) based approach face limitations of temperature drop and leakage issues. To address this issue, an evaporative cooling method that can enhance panel efficiency is investigated. The present study demonstrated a simple, optimized, and cost-effective evaporative cooling for hot and dry climate conditions. The system consists of jute cloth attached directly to the PV panel backside and water flowing from the top header to the jute cloth under gravity has been experimentally investigated in outdoor conditions during summer. The electrical and thermal characteristics (with and without cooling) of the panel were measured. The finding shows that the jute cooling in PV panels leads to a substantial reduction in average temperature by 18°C and a corresponding increase in electrical efficiency by 10.31%. The jute-cooled panel shows an average and maximum output power improvement of 4.33 and 7.10 W, respectively, compared to the referent panel, while consuming only 0.55 l of water per hour. The study also investigated the effect of water failure on jute cooling and water ingress to the junction box. In the event of water cooling system failure, the panel’s temperature increases by an average of 6°C in comparison to the referent panel. Furthermore, the proposed evaporative cooling system shows a cost-incurred payback period of 7 years against the referent system of 5 years.