Experimental study of solar photovoltaic evaporative cooling ventilated cavity

A solution for solar photovoltaic evaporative cooling and ventilation cavities was proposed to address the bottleneck problems faced by photovoltaic modules in the application of building envelope structures, such as increased working temperature and reduced power generation efficiency caused by photovoltaic module heat generation, as well as their potential impact on building cooling and heating loads. This solution involved installing photovoltaic cells on the surface of the building envelope and keeping a certain distance from the building wall to form a ventilation cavity. At the same time, an evaporative cooling device was arranged on one side of the back panel of the photovoltaic cells. By setting up an outdoor test platform and conducting controlled experiments, the impact of the evaporative cooling effect on the thermal and moisture performance of each component of the solar photovoltaic ventilation cavity and the changes in its electrical properties were studied. Experimental results show that the ventilation cavity with evaporative cooling has a significant cooling effect on the photovoltaic front, photovoltaic backplane, cavity backplane and cavity interior. Compared with the ventilation cavity without evaporative cooling, the average temperatures of these parts are reduced by approximately 3.7, 7.6, 4.5, and 3.9 ℃, respectively, with the percentage reductions being 10.2%, 20.8%, 13.6%, and 11.9% respectively. At the same time, the all-day average electrical power of the ventilation cavity with evaporative cooling is improved by approximately 15.9% compared to the ventilation cavity without evaporative cooling. These experimental data verify the effectiveness of evaporative cooling technology in reducing the operating temperature of photovoltaic modules and improving the power generation efficiency of photovoltaic modules, and provide data support for the further application of photovoltaic building integration.