Recycling of photovoltaic modules: Technologies, comparative insights, challenges, and future outlooks

As solar energy becomes a cornerstone of the global renewable energy transition, the environmental challenge of managing end-of-life photovoltaic (PV) modules is becoming increasingly urgent. The rapid expansion of PV deployment has been driven by three technologies: crystalline silicon (c-Si), thin-film, and emerging technologies, with c-Si leading the commercial adoption. Although numerous studies on PV recycling exist, comparative assessments across PV technologies remain limited, particularly regarding commercial practices, key challenges, and future perspectives. This review provides insight into recycling approaches for major PV technologies, including c-Si, thin-film, and perovskite solar cells. Comparative recycling challenges across three PV technologies are outlined, emphasising how material composition shapes recycling routes. Commercial and pilot-scaled recycling practices across different regions are summarised, largely employing mechanical methods alongside hydrometallurgy for metal recovery. Despite progress, recycling challenges persist, including difficulty in recovering intact silicon wafers and high-purity silver, extensive chemical and energy demand, processing and transportation costs, and gaps between current industrial recovery conditions and PV-grade material regeneration requirements, with additional considerations arising for emerging space-based power systems. Future directions include technological improvements and supportive policy frameworks. Technological areas include robotic dismantling, developing emergent technologies, and design-for-recycling at the PV manufacturing stage. Policy measures, like extended producer responsibility, stakeholder collaborations, and optimised logistics are discussed. Overall, these advances show promise in improving circularity and enabling the sustainable scaling of the PV industry.