Safe- and sustainability-by-design approaches for energy storage systems in a green and circular economy

Stationary energy storage systems (ESS) play an essential role in the energy transition, which is why the safety and sustainability of these ESS is increasingly coming to the fore. In recent years, lithium-ion batteries, flow battery systems and combinations of these have been installed. Although there has been some progress in the development of safe and sustainable ESS, the environmental and social impacts are still an under-researched topic. Therefore, one aim of the SuESS research project is to apply the safe and sustainable by design (SSbD) approach to selected ESS, covering the whole life cycle using life cycle assessment (LCA). The focus will be on flow batteries (e.g. vanadium or vanilla-based) and lithium-ion batteries, including possible substitutes (e.g. sodium-ion batteries) with a storage capacity of >80 kWh. An LCA and a social LCA will be carried out to identify environmental and social hotspots.he results will be compared and the advantages and disadvantages of the different ESS will be shown. Based on the (social) LCA results, the SSbD concept is implemented, which also includes an analysis of health and safety aspects at the workplace. In cases where sufficient information on eco- and human toxicity cannot be found, toxicological tests of battery materials and compounds with model organisms (e.g. daphnia) are performed and these data are processed and added to the LCI. The life cycle management of different ESS can have a major impact on sustainability. Therefore, real data from an operating ESS and end-of-life management data are collected and analysed using probability simulations. This allows the analysis of cycle stability, capacity decay, self-discharge as well as maintenance costs of the ESS. Finally, guidelines for the assessment of risks, sustainability and cycle capability will be derived based on the project results. This will provide a basis for decision-making on green deal investments of ESS.