A comprehensive review on the recycling technology of silicon based photovoltaic solar panels: Challenges and future outlook

With the aim of realizing the goals of the Paris Agreement, annual solar power generation on a global scale using silicon PV panels had exceeded 1000 TWh by the end of 2021. Mass installation of silicon-based photovoltaic (PV) panels exhibited a socioenvironmental threat to the biosphere, i.e., the electronic waste (e-waste) from PV panels that is projected to reach 78 million tonnes by the year 2050. Recycling PV panels through e-waste management is crucial step in minimizing the environmental impact of end-of-life PV systems such as the release of heavy metals into the environment. An increasing amount of academic research on recycling approaches to PV panels that suggests different technology and policy challenges remain. The present review critically evaluates a range of recycling solutions, encompassing both lab-scale and pilot-scale research, and conducts analyses of their cost and environmental implications. A detailed discussion of the recycling policies adopted by governments worldwide to handle e-waste has also been provided. In this review article, the complete recycling process is systematically summarized into two main sections: disassembly and delamination treatment for silicon-based PV panels, involving physical, thermal, and chemical treatment, and the retrieval of valuable metals (silicon, silver, copper, tin, etc.). Furthermore, technical, and non-technical challenges and prospects are identified to guide future exploration and innovation. In the pursuit of sustainable recycling of solar PV panels, technology convenience, cost-effectiveness, and social desirability should come together to develop innovative recycling technologies with a high recovery rate of valuable metals.