Experimental study of bifacial photovoltaic wall system incorporating thermochromic material

In this study, we innovatively propose a bifacial PV wall system combined with thermochromic materials (BPVWTC). The system combines thermochromic materials and bifacial PV technology on a building facade to passively and adaptively improve the overall solar efficiency of the building facade by taking advantage of the passive temperature response properties of the thermochromic materials and the power generation benefits of bifacial PV. The designed thermochromic glass with a transition temperature of 35.8 degrees C maintains a high visible light transmittance of 88.6 % in the transparent state, while the transmittance drops sharply to 0.6 % in the opaque state; in addition, a bifacial PV module with a coverage of 70 % is designed, and an experimental setup is set up based on it to validate the power generation gain of the system under indoor steady state conditions. Subsequently, the BPVW-TC system model was tested under different weather conditions in Hefei, China, and the results showed that the system could achieve solar energy utilisation of up to 38.8 % and solar thermal efficiency of up to 83 % on a sunny summer day.