A possibility of developing an environmental-friendly photovoltaic/thermal (PV/T) solar panel, which can shut high temperature radiation within a panel box, was experimentally confirmed. The panel has a decompression-boiling heat collector, which can absorb heat from the PV module and can keep the air and the cover glass inside the panel box at lower temperature by using lower boiling temperature of working fluid under vacuum condition. The panel also has an emboss-processed cover glass, which can totally reflect the high temperature heat radiation from the PV module within the panel box. The experimental results using a single PV/T system showed that it could keep the heat radiation temperature from the PV/T solar panel surface around 45 °C even in summer; it provided the hot water at least 60 °C by controlling the flow-rate; and it produced 71.3% of solar energy in total as electricity and 40 °C heat, in summer, Yokohama, Japan. Highly efficient utilization of solar energy with small environmental heat-load would be possible by using the proposed PV/T system.
Solar Energy, Volume 199, 15 March 2020, Pages 510-520,