Modelling Recycling in Life Cycle Assessment of Perovskite/Silicon Tandem Modules
Résumé
Perovskite on silicon tandem is a promising photovoltaic (PV) technology that can help achieve module power conversion efficiencies beyond 30%. To ensure its potential on the path towards sustainable development, an appropriate end-of-life (EoL) management is critical. The environmental consequences of such EoL management should be evaluated using widely accepted methods, if possible, objective and standardized. The aim of this research is to identify the most suitable methodological approaches to account for recycling when modelling the life cycle of PV modules. Life cycle assessment (LCA) was applied to determine the environmental impacts of a perovskite/silicon tandem system over its whole life cycle. A functional unit of 1 m2 of perovskite/silicon tandem modules was used. Six different approaches for EoL modelling were applied to analyze the effect on the LCA results. The results for the climate change category range from 41 to 58 kg CO2-eq/m2 and the Cumulative Energy Demand (CED) from 530 to 714 MJ/m2 . For the evaluated categories, the cut-off with economic allocation provides the highest results and the closed-loop allocation the lowest. Different EoL modelling approaches lead to non-negligible differences in the results. A clear justification of methodological choices related to EoL modelling is, therefore, essential to ensure the representativeness of the LCA results. With respect to the choice of EoL modelling for a prospective LCA of PV module including recycling, it is recommended: 1) choosing an intermediate solution for EoL modelling that provides incentives for both the use of recycled material as an input and the choice of recycling as the EoL preferred option, 2) using the cut-off method and the closed-loop allocation for the sensitivity analysis and to check the robustness of the results.