Comparative Life Cycle Assessment of End-of-Life Silicon Solar Photovoltaic Modules

Abstract

The cumulative global photovoltaic (PV) waste reached 250,000 metric tonnes by the end of 2016 and is expected to increase considerably in the future. Hence, adequate end-of-life (EoL) management for PV modules must be developed. Today, most of the EoL modules go to landfill, mainly because recycling processes for PV modules are not yet economically feasible and regulation in most countries is not yet well established. Nevertheless, several methods for recycling PV modules are under development. Life cycle assessment (LCA) is a methodology that quantifies the environmental impacts of a process or a product. An attributional LCA was undertaken to compare landfill, incineration, reuse and recycling (mechanical, thermal and chemical routes) of EoL crystalline silicon (c-Si) solar modules, based on a combination of real process data and assumptions. The results show that recovery of materials from solar modules results in lower environmental impacts compared to other EoL scenarios, considering our assumptions. The impacts could be even lower with the adoption of more complex processes that can reclaim more materials. Although recycling processes can achieve good recycling rates and recover almost all materials from solar modules, attention must be paid to the use of toxic substances during the chemical routes of recycling and to the distance to recycling centres due to the impacts of transportation.