Experimental investigation on the enhanced performance of a solar PVT system using micro-encapsulated PCMs

Abstract

In a photovoltaic–thermal (PVT) solar collector, a small percentage of the absorbed solar radiation can be converted into electricity and the rest become heat. The heat could be collected through various working mediums. It is of great practical significance to study PVT system and improve its performance further. In this study, an experimental PVT system using MPCM (Microencapsulated Phase Change Material) slurry as the cooling medium was designed and established. The comprehensive performance of the PVT system was studied. The measured electrical and thermal efficiency of the PVT system using MPCM slurry or tap water under various conditions were compared. Moreover, the MPCM slurry was also used as the working fluid in an outdoor PVT system. The practical performance was compared with those of a traditional water-cooled PVT system and a similar system with PCM layer. The results showed that increasing the flow rates of the MPCM slurry could reduce the temperature of PV cell and improve the thermal and electrical efficiency. The performance of the present PVT system using MPCM slurry is better than that using pure tap water or water with a PCM layer. The average electrical efficiency and the maximum thermal efficiency of the system can effectively increase by 0.8% and 13.5% respectively. The slurry containing low concentration MPCM could enhance the performance, indicating the feasibility of the actual application in solar PVT system.