Life cycle assessment of semi-transparent photovoltaic window applied on building

Abstract

The Semi-Transparent Photovoltaic (STPV) Window is a new form of building integrated photovoltaics (BIPV), which not only can generate electricity, but also improve indoor light and thermal environment. The STPV window was designed, manufactured and applied on a test building. Energy and environmental benefits were studied. The research site is located in an area with solar radiation diversification. The parameters of the life cycle assessment (LCA) model are derived from the database, experimental data and the electricity simulation model. The two important indicators, energy payback time (EPBT) and greenhouse gas payback time (GPBT), are selected to analysis this system, and another seven environmental indicators are considered for different aspects. According to the research findings, the EPBT of the STPV window is 13.8 years, and the GPBT 10.4 years, which are both less than the preset service life of 25 years. The results show that the STPV window can reduce pollution and the waste of non-renewable resources. The optimization analysis connected with the LCA study was carried out based on the critical parameters of the STPV window application in buildings. Optimal directions and preferable locations can result in the STPV window being more economical and sustainable. With increase of the window-to-wall ratio (WWR) and the coverage ratio of PV cells, the EPBT and GPBT gradually become shorter. Following to the research findings, suggestions are put forward to effectively reduce the life cycle cost of BIPV systems.