Combining circularity and environmental metrics to assess material flows of PV silicon

Abstract

A product made from virgin raw materials that ends up in a landfill presents a linear supply chain model. Today's photovoltaic (PV) industry is still largely based on this model. With the increasing volume of production, the raw materials required for it, and consequently the volume of waste, the application of circular economy principles in the PV sector can significantly increase its environmental efficiency. This study analyzes the impact of circularity on the supply chain of PV silicon used for PV module production. Four scenarios based on the combination of technological pathways and circularity options are created. Their evaluation is carried out by the methodologies of Material Circularity Indicator (MCI) and Life Cycle Assessment (LCA). The State-of-art case of the PV polysilicon supply chain corresponds to the MCI score of 0.54. Closed-loop circularity solutions provide the MCI score of 0.80 presenting the potential for a circular economy approach in the industry. LCA results show the reduction of environmental impact by 12% with improved circularity. The study presents the benefits of potential circularity options within the supply chain as well as the impact of technological development on the polysilicon demand.

Keywords

• circularity
• life cycle assessment
• photovoltaics
• polysilicon
• metrics