Researchers Model 1,708 Pathways for Global PV Waste Recycling

Researchers have developed a comprehensive framework to evaluate the economic and climate benefits of local versus outsourced PV waste recycling. The framework, which was developed by an international research group, covers mainstream recycling technologies, 32 regions, various waste-trade configurations, and subsidy schemes.

The researchers assessed 1,708 different recycling scenarios, which combined assumptions about future PV decommissioning, recycling technologies, international waste trade, and subsidy policies. The technology pathways included business as usual (BAU), economic priority, carbon priority, and technology diffusion. The trade scenarios covered local recycling, extended producer responsibility (EPR)-oriented trade, expanded global trade, and regional trade.

The researchers also tested five subsidy schemes: no subsidy, continuous subsidy, declining subsidy, low-carbon-price support, and high-carbon-price support. These combinations were assessed across 28 PV decommissioning scenarios to compare their effects on recycling economics, climate benefits, and regional inequality.

The framework projects that global PV waste will reach 297 million to 402 million metric tons by 2060, with middle-income regions such as China becoming major contributors after 2040. Despite anticipated technological advances, global PV waste recycling is not expected to reach its break-even point for more than a decade.

According to the results, combining region-specific recycling technologies with outsourced recycling strategies produces the highest global net benefits. The approach could reduce greenhouse gas emissions by up to 3.32 billion metric tons of CO2 equivalent and generate cumulative net benefits of $529.1 billion to $935.5 billion by 2060.

However, the same process can concentrate recycling revenues and technological development in a relatively small number of regions. This means that strategies that perform well in terms of overall global benefits may produce a more uneven distribution of those benefits across regions.

The researchers found that a well-designed declining-subsidy scheme can help mitigate these inequalities, particularly during the early stages of market development. A declining subsidy, which is gradually phased out once recycling becomes economically viable, can reduce regional disparities more effectively than continuous subsidies while requiring only a small fraction of the fiscal expenditure.

## Framework and Methodology

The researchers developed an integrated global framework that links material supply constraints, future PV deployment, and waste generation with region-specific recycling technology pathways, cross-regional waste flows, and policy interventions. The framework captures both the economic and climate benefits of PV recycling and how those benefits are distributed across regions.

The researchers first modeled future prices for copper, aluminum, silver, and silicon. They then fed these projections into the Global Change Analysis Model (GCAM) to estimate PV deployment under different socioeconomic and climate pathways. The resulting capacity projections were used in a dynamic material-flow analysis to calculate end-of-life PV waste through 2060.

Finally, the researchers combined life-cycle assessment with life-cycle cost analysis to estimate the climate and economic impacts of recycling under different technology pathways, waste-trade arrangements, and subsidy schemes.

## Results and Findings

The researchers found that combining region-specific recycling technologies with outsourced recycling strategies produces the highest global net benefits. The approach could reduce greenhouse gas emissions by up to 3.32 billion metric tons of CO2 equivalent and generate cumulative net benefits of $529.1 billion to $935.5 billion by 2060.

However, the same process can concentrate recycling revenues and technological development in a relatively small number of regions. This means that strategies that perform well in terms of overall global benefits may produce a more uneven distribution of those benefits across regions.

The researchers also found that a well-designed declining-subsidy scheme can help mitigate these inequalities, particularly during the early stages of market development. A declining subsidy, which is gradually phased out once recycling becomes economically viable, can reduce regional disparities more effectively than continuous subsidies while requiring only a small fraction of the fiscal expenditure.

## Conclusion

The researchers' comprehensive framework provides valuable insights into the economic and climate benefits of local versus outsourced PV waste recycling. The findings highlight the importance of considering supply-side material constraints, region-specific recycling technologies, and subsidy schemes in evaluating the effectiveness of different recycling strategies.

The study's results suggest that combining region-specific recycling technologies with outsourced recycling strategies can produce the highest global net benefits. However, this approach can also concentrate recycling revenues and technological development in a relatively small number of regions.

The researchers' findings have important implications for policymakers and industry stakeholders seeking to develop effective strategies for managing PV waste. By considering the economic and climate benefits of different recycling approaches, policymakers can make informed decisions about how to allocate resources and promote sustainable development.

## Authors and Affiliations

The research was conducted by scientists from China's Shandong University, Huazhong University of Science and Technology, the University of Hong Kong, Taiyuan University of Technology, Australia's Adelaide University, and Sweden's Linköping University.

The study was published in the journal *nature* under the title "Towards an equitable future of global photovoltaic waste recycling.