Experimental and numerical investigation of a multi-functional photovoltaic/thermal wall: A practical application in the civil building

Abstract

This article proposed a multifunctional PV/T (MFPV/T) wall with the built-out PV cells. While generating electricity, this system could produce warm air in heating seasons and hot water in non-heating seasons. Besides, this novel structure could solve the issue of unreliability of the conventional PV/T collectors. In this work, firstly, the thermal and electrical performance of the proposed system was tested in a civil building. Then, the performance comparison between the MFPV/T walls with the built-out and built-in PV cells (EMFPV/T and IMFPV/T walls) was conducted based on the validated simulation models. Finally, the impact of change in parameters on the system performance was analyzed. The main results were: (1) During the experimental period, the thermal and electrical efficiencies were 17.55% and 13.88% in PV/air mode while those were 8.92% and 14.09% in PV/water mode. (2) During the studied three days, the exergy of the EMFPV/T wall was higher than that of the IMFPV/T wall by 390 Wh for PV/air mode and 750 Wh for PV/water mode. (3) Decreasing cavity depth and increasing vent airtightness, PV coverage ratio, and water tank volume had different effects on the energy output, but they all increased the exergy production.