Exergy analysis of building integrated semitransparent photovoltaic thermal (BiSPVT) system

In this paper, an exergy analysis of building integrated semitransparent photovoltaic thermal (BiSPVT) system has been carried out. In the proposed system, the room below building integrated semitransparent photovoltaic thermal system has been considered as an air-conditioned (constant room temperature). Energy balance equation for each components namely semitransparent photovoltaic roof, floor and room air have been given. Based on energy balance, an analytical expression for room air, solar cell and room floor temperatures have been derived along with solar cell electrical efficiency. Further by considering the day lighting parameters, an overall exergy of the proposed system has been derived for different number of air change between the room and ambient air. It has been observed that there is reduction in room air and solar cell temperatures with an increase of number of air changes. However, solar cell electrical efficiency increases with decrease in temperature of solar cell. Further, it is found that an electrical power and illumination inside the room are more dominating in comparison with thermal exergy. An increase of 1.15% in an overall exergy is observed for the number of air changes varies from 0 to 4. Experimental validation of theoretical model has also been carried out.