The Semitransparent Photovoltaic (STPV) module could replace the glazing materials of the skylight in residential buildings, which minimizes the energy consumption in artificial lighting, heating, and cooling load of the building. In this study, the electrical, thermal and daylight performance of STPV skylights are investigated for actual outdoor environmental condition by installing it on the rooftop window of the experimental room at Kovilpatti (9°10′0″N, 77°52′0″E), Tamilnadu, India. The STPV modules are specially designed and fabricated for the skylight with specific PV cell coverage ratio (PVCCR) values are 0.62, 0.72, and 0.85. The various parameters are analysed such as power generation, electrical efficiency, module surface temperatures, solar heat gain, and reduction in cooling load, illuminance, daylight factor and CO2 mitigation by the STPV skylights. It is revealed that the maximum daylight factor of 4% and indoor illuminance of 850 lux is obtained in 0.62 PVCCR and reduction in cooling load due to the installation of PV skylight is calculated as 248 kWh/year during summer. On observation, it is found that the overall maximum energy saving potential is 450 kWh/year for 0.72 PVCCR, and its unit cost of the power generation is estimated as 0.0354 $/kWh. •STPV skylights with specific PV cell coverage ratio (0.62, 0.72 and 0.85) is investigated.•The effect of STPV skylight in building is compared with clear glass window.•The optimum PVCCR ratio of daylight and reduction in cooling load is 0.72.•The energy metrics and economic analysis of the STPV skylights are investigated.