Necessity for recycling photovoltaic glass: Managing resource constraints and environmental impacts of antimony in terawatt scale photovoltaics

Abstract

Terawatt-scale photovoltaic (PV) deployment, with an annual installation of 3.4 TW, is essential to combat climate change. However, manufacturing this amount of PV requires a critical evaluation of material demands, particularly antimony (Sb), which is widely used in PV glass production. Our study focuses on two key aspects: the resource constraints of Sb for terawatt-scale PV deployment and the mitigation of its environmental impacts. We find that supporting 3.4 TW/year of PV deployment would require approximately 0.42 million tonnes (Mt) of Sb annually, which is more than five times the current global production. Current Sb reserves could sustain the PV glass industry for only about five years, highlighting the urgent need to address resource limitations. Recycling broken PV glass (cullet) offers a partially sustainable solution by reducing dependence on virgin Sb and extending the lifespan of existing reserves. Our analysis indicates that, under moderate collection and recycling assumptions and using realistic Sb-recovery efficiencies (30–60 %), recycling of end of life (EOL) PV glass cullet could supply only ∼2–11 % of annual Sb demand for PV glass, underscoring that the majority of Sb will still need to come from primary production and that cullet recycling alone cannot close the supply gap. Reuse of whole glass provides an additional pathway to ease pressure on virgin Sb while also addressing environmental concerns, such as Sb leaching into soil and groundwater from landfilled PV glass. Existing methods such as hot-knife and water-jet processes can recover intact glass, which can then be reused in the manufacturing of new PV modules.