Analytical expressions for temperature dependent electrical efficiencies of thin film BIOPVT systems

Analytical expressions for the electrical efficiencies (ηm) of building integrated opaque photovoltaic thermal (BIOPVT) systems based on thin film photovoltaic (PV) modules have been derived. The expressions are valid for different climatic conditions and different design parameters of the building. The systems based on a-Si, CdTe and CIGS thin film solar modules have been analyzed for their energy, exergy and characteristics performance with and without air duct, for a typical day of Srinagar, India. The module daily average electrical efficiency (ηm) and average room temperature (Tr) of a BIOPVT system based on a-Si solar modules without air duct were found to be 7.25% and 18.7 °C respectively, whereas with air duct the ηm and Tr of the same system have been found to be 7.57% and 15.2 °C respectively. The number of air changes (N) and mass flow rates (ṁf) have been found to have a significant effect on Tr.