A comprehensive review on recycling end of life solar photovoltaic panels

Significant advancements in solar cell technology, including thin-film, tandem, and traditional silicon-based cells, have driven the widespread adoption of solar photovoltaic (PV) panels. Global installed PV capacity is projected to grow from 400 GW in 2017 to 4500 GW by 2050, increasing demand for critical materials like In (38–286 times), Ag (4–27 times), and others (2–20 times). With solar panels having a 25-year lifespan, end-of-life (EoL) PV waste is expected to reach 78 million tons by 2050, posing a major environmental challenge without effective recycling.

Recycling methods for crystalline silicon panels are advanced, while thin-film technologies lag slightly. Key challenges include removing ethylene–vinyl acetate (EVA) encapsulation and extracting metals without releasing toxic gases or effluents. High-value recycling focuses on recovering critical (e.g., Si, Ga), strategic (e.g., Cu), and precious metals (e.g., Ag) through hydrometallurgical methods after delamination (physical, thermal, or chemical). Thermal methods like pyrolysis can emit harmful gases, whereas chemical treatments (e.g., HNO₃) offer cleaner, high-quality material recovery.

Innovative recycling technologies support the circular economy, reduce waste, lower CO₂ emissions, and provide economic benefits. This review outlines solar panel structures, evaluates current EoL recycling processes, and presents industrial-scale methodologies, emphasizing the need for sustainable solutions to manage growing PV waste to become a significant environmental challenge in the coming decades.