Integrating Batteries in the Future Swiss Electricity Supply System: A Consequential Environmental Assessment

Stationary batteries are projected to play a role in the electricity system of Switzerland after 2030. By enabling the integration of surplus production from intermittent renewables, energy storage units displace electricity production from different sources and potentially create environmental benefits. Nevertheless, batteries can also cause substantial environmental impacts during their manufacturing process and through the extraction of raw materials. A prospective consequential life cycle assessment (LCA) of lithium metal polymer and lithium-ion stationary batteries is undertaken to quantify potential environmental benefits and drawbacks. Projections are integrated into the LCA model: Energy scenarios are used to obtain marginal electricity supply mixes, and projections about the battery performances and the recycling process are sourced from the literature. The roles of key parameters and methodological choices in the results are systematically investigated. The results demonstrate that the displacement of marginal electricity sources determines the environmental implications of using batteries. In the reference scenario representing current policy, the displaced electricity mix is dominated by natural gas combined cycle units. In this scenario, the use of batteries generates environmental benefits in 12 of the 16 impact categories assessed. Nevertheless, there is a significant reduction in achievable environmental benefits when batteries are integrated into the power supply system in a low-carbon scenario because the marginal electricity production, displaced using batteries, already has a reduced environmental impact. The direct impacts of batteries mainly originate from upstream manufacturing processes, which consume electricity and mining activities related to the extraction of materials such as copper and bauxite.