Energy and cost studies of semi-transparent photovoltaic skylight

Sustainability is the trend of the modern building designs, in which solar energy conversion systems and daylighting schemes are widely considered as the important building energy strategies to reduce the peak cooling and electrical demands, generate clean energy and save the building electricity expenditures. A semi-transparent photovoltaic (PV) is a renewable energy product producing electricity via solar cells and allowing natural light entering into the interior spaces for daylighting designs. The PV modules are effective in reducing the cooling demand, especially for the skylight atrium that often receives large solar heat gains. This paper studies the thermal and visual properties, energy performance, environmental and financial issues of such semi-transparent PV skylights. Field measurements including solar irradiance, daylight illuminance and electricity generated were carried out. Case studies based on a circulating atrium were conducted to evaluate the energy use, cooling requirements and monetary implications when the PV skylights together with the daylight-linked lighting controls were applied. The results indicated that such an integrated system could save the overall electricity expenditures and benefit to the environmental and financial aspects.