Sustainability Perspective for Building Integrated Semi-transparent PV Systems

Semi-transparent photovoltaics (STPVs) are innovative technologies that enhance the thermal performance and energy efficiency of buildings. This study evaluates the impact of various STPV technologies, including amorphous silicon and thinner CdTe, when applied to the windows of a medium-sized office building located in four distinct climate zones in the United States: Los Angeles, California; Portland, Oregon; Denver, Colorado; and Baltimore, Maryland. The thermal and optical properties of each STPV type were incorporated into OpenStudio to simulate the building’s annual heating and cooling energy demand, and results were compared to a base case without PV integration. Annual electricity generation was modeled using the HelioScope tool, and the resulting net energy use was calculated to quantify energy savings in heating and cooling demand for each STPV scenario. In addition, environmental and economic impacts were assessed using the U.S. Environmental Protection Agency’s eGRID database and the U.S. Energy Information Administration electricity pricing databases. The results demonstrate the positive impact of both STPV systems across all studied cities. Cooling and heating demands decreased by approximately 20-35% and 5-38% respectively, across all locations, with the most significant reductions observed in Los Angeles. The net energy analysis further confirms the benefits of STPV integration, indicating a total electricity reduction ranging from 34% to 74%. Among the studied locations, Los Angeles shows the highest potential for STPV integration due to its high solar irradiance, which results in greater electricity generation and overall energy savings. As the total electricity use decreases, carbon emissions and electricity costs also reduced by 34-74%, highlighting their benefits for sustainability and cost-efficiency.