Prospective life cycle analysis of a BIPV façade − Life cycle assessment of greenhouse gas emissions using future projections for a case study
Christian Popp, Clara Uhlig, Michael Engelmann
Abstract
• Prospective LCA of BIPV façade in typical built in situation in 2023 and 2033. • Projection of greenhouse gas emissions over life cycle of BIPV façade system. • Projection of electricity mix, production efficiencies and secondary fractions. • Comparison of Chinese and German PV module production chain. • Comparison of static and prospective LCA of BIPV. BIPV façades activate unused surfaces for energy generation and save conventional façade cladding and therefore resources, emissions and energy. However, these advantages can only be recognised by analysing the entire life cycle of BIPV facades and comparing their life cycle performance to facades without photovoltaics. In principle, life cycle analyses are based on static boundary conditions and all assumptions are based on current technology, which can clearly limit the results. In this study, scenario-based prospective life cycle analyses are carried out in order to forecast the future impact of BIPV façades. Two temporal scenarios (2023 and 2033) and three regional scenarios for the entire PV module production chain (Germany, China and mixed Chinese-German) are considered. The prospective approach leads to differentiated results in the context of the underlying boundary conditions and projections compared to a static state of the art approach. The considered progresses from 2023 to 2033 lead to reductions in embodied greenhouse gas emissions of 37.8% (DE), 32.3% (CN-DE) and 30.6% (CN). The reduction of a German compared to a Chinese production rises from 23.5% in 2023 to 37.8% in 2033. In all the scenarios analysed, more greenhouse gas emissions are reduced over the life cycle than are emitted. BIPV façades perform significantly better in comparison with an energetic inactive fibre cement façade.