Green solvents for end-of-life photovoltaic module recycling: Mechanisms, applications, environmental and economic perspectives

The significant rise in photovoltaic (PV) deployment has led to growing concerns over end-of-life (EOL) PV waste, highlighting the need for sustainable recycling technologies. Conventional recycling methods often involve high energy consumption or toxic chemicals. Green solvents have gained considerable attention as promising alternatives. Importantly, green solvents in EOL PV recycling serve two main functions: (i) removing or delaminating polymer encapsulants to separate glass and backsheet, and (ii) leaching valuable metals such as silicon, aluminium, and silver from the solar cells. Despite growing interest, the literature does not yet provide a comprehensive understanding of these applications. This review addresses this gap by examining a range of green solvents such as supercritical fluids, bio-based solvents, water, and deep eutectic solvents in the context of EOL PV recycling. This review found that these solvents offer reduced environmental impact, high separation efficiency of the encapsulation layer, and reusability, with a study reporting solvent reuse up to twenty-four times. Despite these benefits, green solvents face limitations in scalability and cost. Future research should focus on process optimization and the techno-economic feasibility of using these solvents in PV recycling processes.