Industrial Data-Based Life Cycle Assessment of Architecturally Integrated Glass-Glass Photovoltaics

Abstract

Worldwide, an increasing number of new buildings have photovoltaics (PV) integrated in the building envelope. In Switzerland, the use of coloured PV façades has become popular due to improved visual acceptance. At the same time, life cycle assessment of buildings becomes increasingly important. While a life cycle inventory for conventional glass-film PV laminates is available, this is not the case for glass-glass laminates, and in particular, coloured front glasses. Only conventional glass-film PV laminates are considered in databases, some of which are partly outdated. Our paper addresses this disparity, by presenting life cycle inventory data gathered from industries producing coloured front glass by digital ceramic printing and manufacturing glass-glass PV laminates. In addition, we applied this data to a hypothetical façade made of multi-coloured glass-glass laminates and its electricity generation in terms of Swiss eco-points, global warming potential, and cumulative energy demand as impact indicators. The results of the latter show that the effect of the digital ceramic printing is negligible (increase of 0.1%), but the additional glass (4% increase) and reduction of electricity yield (20%) are significant in eco-points. The energy pay-back time for a multi-coloured PV façade is 8.1 years, which decreases by 35% to 5.3 years when replacing the glass rain cladding in an existing façade, leaving 25 years for surplus electricity generation.