Efficiencies of lead halide perovskite photovoltaics (LHP PVs) have increased to over 26%, and over 30% for tandems, and potential for low manufacturing costs puts them on track for near-future commercialization.  While most efforts to date have focused on stability and scalability of LHP PVs, the environmental impact of their manufacturing should be considered, and concern regarding the toxicity of lead (Pb) remains a major challenge to large-scale commercialization. This invited talk will describe two recent studies related to (1) life cycle assessment of cation precursors, and (2) fate of toxic Pb leachate from hypothetical breakage of fielded module arrays.

Devices exhibiting the best combination of high efficiency and long operational lifetimes have used mixed cation perovskite absorber layers such as cesium / methylammonium / formamidinium lead iodide (Cs_x­MA_yFA_1-x-yPbI₃). However, the associated environmental burdens of the supply chains of perovskite precursors should also be considered when selecting compositions for commercialization.  Prior literature based on laboratory-scale data reported a particularly high environmental burden for FA and warned against using these highest-performing film compositions.  Here we used updated data sources, process scale-up concepts, and sensitivity analysis to build commercial-scale life cycle inventory (LCI) models for perovskite precursors. Our life cycle assessment results indicate that the environmental burdens of CsI, MAI, and FAI are similar to each other. This conclusion reveals that the composition can be selected based on PV efficiency and operational stability, without additional constraints of environmental impact. The current cesium supply appears sufficient for near-future perovskite deployment. Our commercial-scale LCI models for perovskite films aid in more transparent and robust environmental analysis that can contribute to industrial manufacturing choices.

Second, we will present a screening-level, EPA-compliant model of fate and transport of Pb leachate in groundwater, soil, and air following hypothetical catastrophic breakage of LHP PV modules in conceptual utility-scale sites. We estimated exposure point concentrations of Pb in each medium and found that most of the Pb is sequestered in soil.  Exposure point concentrations of Pb from the perovskite film fell well below US EPA maximum permissible limits in groundwater and air even upon catastrophic release from PV modules at large scales. Background Pb levels in soil can influence soil regulatory compliance, but the highest observed concentrations of perovskite-derived Pb would not exceed EPA limits under our assumptions. Nonetheless, regulatory limits are not definitive thresholds of safety, and the potential for increased bioavailability of perovskite-derived Pb may warrant additional toxicity assessment to further characterize public health risks.