Silver Flows and In-Use Stocks in China’s Photovoltaic Module Fleet: Dynamic Material Flow Analysis and End-of-Life Recovery Potential

Photovoltaic (PV) deployment in China has accumulated silver in long-lived crystalline-silicon modules, yet the timing and scale of its end-of-life (EOL) release remain uncertain. This study develops a cohort-based dynamic material flow analysis (MFA) for PV modules installed in China during 2000–2025 and projects silver flows to 2060. Technology-specific pure-silver intensities are reconstructed from cell dimensions and efficiency, paste consumption, metallization composition, and technology shares. Weibull lifetime distributions are used to compare four module-lifetime scenarios, while four recovery-rate pathways assess the effect of recovery-capacity timing. Parameter uncertainty is examined using Latin-hypercube Monte Carlo simulation. From 2018 to 2025, technology-weighted pure-silver intensity fell by 62.0% (from 23.33 to 8.86 mg/W), whereas annual installation silver inflow rose by 170.4% (from 1,149.66 to 3,108.88 t). Under the baseline lifetime scenario, EOL silver flow peaks at 739.34 t/yr in 2044, nine years before retired capacity peaks in 2053. At the end of 2025, the in-use stock reached 17,784.12 t, equivalent to 99.5% of cumulative installation inflow. Cumulative potentially recoverable silver during 2025–2060 ranges from 3,606.94 to 15,335.65 t across the specified recovery scenarios. Module lifetime primarily determines release timing, whereas silver intensity affects the magnitude of release. Recovery estimates are scenario-based and do not represent actual secondary-silver production.