Green thermal management of photovoltaic panels by the absorbent hydrogel evaporative (AHE) cooling jointly with 3D porous copper foam (CF) structure

To address the problems of low power generation efficiency and low security of solar photovoltaic cells, a novel and versatile PV panel cooling strategy was proposed; which employed an absorbent hydrogel evaporative (AHE) cooling with 3D porous copper foam (CF) composite structure as an effective cooling component. By comparing natural cooling, comprehensive indoor simulated and outdoor experimental studies were conducted to explore the feasibility of enhancing the electrical output performance of PV cells. The effects of solar irradiation, environment humidity, ambient temperature and wind speed on heat transfer performance and the generated electricity power efficiency of PV with CF-AHE cooling panel were comprehensively analyzed and discussed. Present research demonstrated that the CF-AHE cooling layer of three solar irradiations (0.8, 1.0 and 1.2 sun conditions) could remove 449∼713W/m2 of heat from a photovoltaic cell, which significantly out-performed that of general cooling methodology depending on wind or buoyancy driven ventilation. The results further indicated that CF-AHE significantly reduces the cell temperature, enhancing the temperature uniformity of PV cell modules, i.e., the PV cell temperature ranges from 43–46 °C, markedly lower than the 53–66 °C observed with natural cooling. Additionally, average electrical efficiencies were enhanced by 4.69 %, 8.53 % and 12.84 % compared with that of natural cooling method, respectively. Subsequently, in the field test conducted in Wuhan city of China, current results further showed that our proposed cooling unit has boosted the power generation of PV panels by 14.01 % and reduced PV surface temperature by no less than 10 °C, simultaneously. Therefore, CF-AHE cooling structure can furnish excellent heat transfer characteristics and efficient electrical generation performance of PV panel. This research will provide valuable guidance for design of photovoltaic-AHE cooling systems and verifies the feasibility of such systems.