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

Jeeyoung Park,Dirk Hengevoss,Stephen Wittkopf

doi:10.3390/buildings9010008

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 Only conventional glass-film PV laminates are considered in databases, some of which are partly outdated.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.

Highlights

IntroductionPhotovoltaics (PV) offer great opportunities in densely populated regions such as Switzerland, when installed on the surfaces of buildings
To realistically assess the environmental impact of the entire life cycle of a Multi-coloured glass-glass (MCGG) c-Si PV laminate, this study presents up-to-date data on c-Si production gathered from literature, as well as material and energy flow data from a solar glass and PV laminate supplier
To achieve the goal of the Swiss energy strategy, namely to increase contribution of PVs to the national electricity supply by up to 20% by 2050, Building integrated photovoltaics (BIPV) need to be aesthetically appealing for visual integration while generating electricity with a lower environmental impact than that of the existing

Summary

Introduction

Photovoltaics (PV) offer great opportunities in densely populated regions such as Switzerland, when installed on the surfaces of buildings. This is primarily due to their ability to generate electricity without noise emissions, and deployment in a large range of sizes and forms. Ground mounted photovoltaics are impractical due to the scarcity and high cost of land in Switzerland. Global warming (climate change) is a critical issue drawing wordwide attention, and Switzerland should reduce green house gas emission by 20% in comparison to their 1990 level by 2020 according to Swiss law (the CO2 Act). Nuclear power, which is CO2 -free and generates about 40% of Swiss electricity, will phase out [2]

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