Experiments and simulations on the energy performance of semi-transparent photovoltaic roof-integrated skylight glazing

Photovoltaic (PV) cells integrated with building roof skylights not only generate electricity but also influence the thermal performance of the roof. In this paper, the thermal mathematical model of a semi-transparent photovoltaic insulating glass unit (STPV-IGU) integrated with the roof is established and validated by experiments. Case studies are conducted by using the roof-integrated STPV-IGU in Shanghai, and an equivalent electrical method is used to evaluate the energy performance of roof-integrated skylight STPV-IGU. The equivalent electricity of heat-gain entering the room through STPV-IGU and total equivalent electricity of roof-integrated STPV-IGU is 16.6 kWh/m2 and 12.1 kWh/m2 in summer, respectively. The equivalent electricity of heat-gain entering the room through STPV-IGU and total equivalent electricity of roof-integrated STPV-IGU are −16.3 kWh/m2 and −4.0 kWh/m2 in winter, respectively. Compared with traditional insulating glass unit, the STPV-IGU can significantly reduce the heat-gains through glazing in summer, but increase indoor heat-loss in winter.