A comparative experimental study on the performance of photovoltaic thermal air collectors

Solar photovoltaic thermal air collectors are simple in structure and free from frozen tube damage, and can be used in heating air and drying agricultural products. However, there is a lack of modular collectors that can be easily installed when building in villages and towns. In this paper, the thermal and electrical performance of two types of solar photovoltaic thermal air collector modules with different structures was compared and analyzed. The two modules can be combined and spliced into different sizes to satisfy the energy needs of the users and fit the size of the site roof, providing both electrical and thermal energy to the building. An experimental platform for collector performance testing was constructed to investigate the thermal and electrical performance of the solar photovoltaic thermal air collector modules in the heating mode and non-heating mode. The results show that the thermoelectric comprehensive efficiency of the closed and semi-closed structures increased by 11.6%·m−1·s and 19.4%·m−1·s, respectively, with the increase in the inlet air velocity. Additionally, with the increase in the inlet air temperature, the thermoelectric comprehensive efficiency of the closed and semi-closed structures decreased by 0.83%·°C−1 and 1.9%·°C−1, respectively. Under the experimental conditions, the thermoelectric comprehensive efficiency of the semi-closed solar photovoltaic thermal air collector reached a maximum of 97.4%. The modular solar photovoltaic thermal air collector has potential applications for farmers and herders in cold, remote areas.