Photovoltaic panel waste assessment and embodied material flows in China, 2000-2050

Solar photovoltaics (PV) is one of the most promising renewable energy sources for climate change mitigation. However, not all green energy installations may not continue to be sustainable after their service life. With the largest installed solar capacity in the world, China is expected to face significant challenges in managing the end-of-life (EoL) PV panels in the coming decades, which have not been well addressed yet.Further, the massive deployment and planning of solar energy systems in China has led to a dramatic increases in demand for raw materials, which places more pressure on the available resources. In this study, we have developed a dynamic, technology-based material flow analysis model to clarify the stock, flow and secondary supply potential of waste PV panel materials in China from 2000 to 2050. The waste generation and circular flow characteristics of the component materials in PV panels are comprehensively investigated, which set important boundary conditions for the recovery and recycling of key materials. The results show that approximately 134 million metric tons (Mt) and 72 Mt of waste PV panels will be cumulatively generated in China up to 2050 under the early loss and regular loss scenarios, respectively. Polysilicon glass accounts for the largest share of PV waste, nearly 64% by weight, followed by aluminum (16%) and steel (11%). Precious metals such as Ag, Ga, In, and Te, account for less than 1% of the total PV waste, but can provide considerable economic benefits if recycled wisely. The potential of secondary resources from PV waste may reduce the supply pressure on the natural materials to some extent, but they could not fully mitigate the material supply resks. We suggest that stakeholders in the solar energy industry should take urgent actions, including recycling technology innovations, effective collection systems and incentive measures, to address the growing challenge of waste PV panels in China.