Anticipating the wave: County-level evidence for recycling strategies of photovoltaic waste in China

China's rapid expansion of solar photovoltaic (PV) installations is set to generate a large wave of module retirements. However, existing studies primarily forecast waste at the national or provincial scale, providing limited spatial evidence on where retired modules will emerge, which constrains recycling system planning. This study uses satellite-derived PV identification imagery to construct a county-level installation dataset covering 1593 counties nationwide. We further apply multi-scenario combined with Weibull modelling to project spatially explicit PV retirements to 2050; centre-of-gravity analysis and economic thresholds to identify when and where recycling becomes viable. The results show that PV retirements will accelerate after 2025, with the cumulative retired areas reaching 7000–15,000 km² by 2050, roughly equaling to the area of 1 million football pitches at the lower end. County-level analysis reveals hidden hotspots, such as Anda and Weining, that provincial aggregates may overlook. Northwest provinces could establish intra-provincial recycling systems before 2030, reducing the transport burden by 64% compared with regional-scale consolidation; 9 provincial-level units, including Beijing and Fujian, face a risk of falling outside formal recycling networks, for which long-term coordinated recycling offers an effective solution. Under the early-loss scenario, the economic feasibility signal advances by 5–7 years, highlighting the importance of maintenance.