Assessing tin demand and supply pressures under terawatt-scale photovoltaic deployment

Terawatt-scale photovoltaic (PV) deployment will materially increase demand for solder, for which tin is the primary constituent. We quantify potential tin demand to 2050 by combining historical global refined-tin production/consumption (1999–2024) with trend-based machine-learning (ML) forecasts and exogenous PV deployment scenarios. The analysis uses an accounting approach in which the ML forecasts form a trend-continuation baseline (BAU) and PV demand is overlaid to explore conditional supply risks. Under BAU, refined production grows slowly while consumption stabilises; when realistic PV trajectories and replacement demands are added, several scenarios generate substantial and persistent gaps between refined tin demand and plausible BAU supply paths. Sensitivity analysis shows that raising the Recycling Input Rate (RIR) materially reduces the shortfall, while reductions in tin intensity and diversification of supply also mitigate risk. Recent declines in refined output reflect supply disruptions and a post-2020 slowdown in consumption; available data do not indicate a clear global decline in tin ore grades. Policy measures combining increased recycling, reduced tin intensity, and targeted supply diversification are therefore the most effective near-term responses to reduce vulnerability.