Materials constraints for long-term photovoltaic sustainability: renewal dynamics highlight critical mining and recycling needs

Energy transition scenarios anticipate a substantial increase in material demand driven by the large-scale deployment of low-carbon technologies, particularly photovoltaics. Existing assessments typically limit their time horizon to 2050, which aligns with political targets and allows identifying short-term supply risks, but remains insufficient for evaluating the long-term material requirements associated with technology replacement and sustained operation. We develop a dynamic stock–flow model to explore PV deployment trajectories until 2100, incorporating assumptions on material intensity reductions, module lifetimes, and both mining and recycling supply. Using IEA’s Net Zero Emissions scenario, we find that the material requirements for maintaining the global PV fleet could create significant pressure on several key resources after 2050. Copper emerges as the most critical material: under a business-as-usual supply scenario, PV demand could account for more than 50% of annual primary copper production by 2080. Comparable long-term constraints appear for silver and aluminium. These pressures arise beyond mid-century, underscoring the importance of extending assessment horizons for evaluating the sustainability of low-carbon technologies. The large number of PV modules reaching end-of-life after 2050 will create a significant secondary feedstock. With efficient recycling, this could delay material shortages by decades. Recycling 40% of end-of-life panel copper would reduce PV’s share of primary copper demand to around 30% in 2080. Overall, our results indicate that long-term material requirements for sustaining PV may impose supply pressures comparable to, or exceeding, those associated with initial deployment, highlighting the need for coordinated strategies on material efficiency, recycling, and long-term resource planning.