Performance Evaluation of Semi-transparent CdTe Thin Film Photovoltaic for Building Façade Applications

Abstract

In recent years, building integrated photovoltaic (BIPV) applications have gained a considerable interest. Different semi-transparent photovoltaic (STPV) glazing can be used in such applications. This thesis aims to investigate the thermal performance, energy performance and daylight performance of a CdTe thin-film based semi-transparent PV glazing of different transparencies. Outdoor and indoor experimental setups were installed, in Penryn, UK, to investigate the performance of 35%, 25%, 19% and 0.5% CdTe thin-film based semi-transparent photovoltaic glazing in comparison to conventional clear glazing under realistic conditions. Data from the experimental setups were collected in different day conditions and different orientations that are South and South West. Overall heat transfer coefficient (U-value) and solar heat gain coefficient (SHGC) were calculated for thermal performance evaluation. Net energy performance was evaluated for energy performance assessment. Daylight glare index (DGI) and daylight factor (DF) were calculated for daylight performance evaluation. Results showed that, CdTe STPV glazing are better thermal insulators than conventional single glazing, and CdTe STPV glazing with lower transparencies have better thermal insulation property than higher transparency ones. In addition, compared to conventional single glazing, the application CdTe STPV glazing can achieved a net energy saving up to 20%. Moreover, Using CdTe STPV as a glazing façade can control the daylight glare inside the enclosures to acceptable levels, it also permits for usable daylight to be transmitted into enclosures.