Reduced global warming potential in carbon-based perovskite solar modules: Cradle-to-gate life cycle analysis

Given the superior stability, technologically developed and cost effectiveness of carbon-based perovskite solar cells over conventional metallic electrode-based architectures, this work investigates the environmental performance of two industrial front-runners architectures i.e., high temperature processed carbon-based perovskite solar modules (CPSMs) and low temperature processed CPSMs using cradle-to-gate Life Cycle Assessment analysis assuming a manufacturing plant in India. According to the study, most of the impacts are due to energy consumption in the annealing and screen print paste process used in ETL, perovskite, HTL and cathode layer for both the architectures. Material selection for the perovskite and other layers has a significant environmental impact on both architectures. Compared to low temperature processed architecture, high temperature processed CPSMs have a greater environmental impact. For a five-year lifetime, the global warming potential (GWP) values for high temperature and low temperature processed CPSMs are 0.180 kg CO₂-eq and 0.126 kg CO₂-eq, respectively, which are marginally higher than those indicated for commercially available silicon solar cells. Thus, a sensitivity analysis was performed to determine the minimum lifetime required to compete with GWP values comparable to commercial PVs. High and low temperature processed CPSM needed 16 and 11 years of lifetime, respectively, to match silicon's 25 years of lifetime. On the other hand, the study finds the human toxicity contribution by mono-silicon is extremely high compared to the two CPSM architectures because of the contribution by electricity (44.01%) and use of heavy metals such as copper (16.83%) and steel (11.52%).