EPRI Battery Energy Storage Systems (BESS) Failure Incident Database

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EPRI and the other co-authors of this paper call for more transparency and data-sharing by the storage industry, especially of root cause investigations. With additional incident identification and classification, future work could build on this initial report to provide deeper insights on root causes and effectiveness of preventative measures.
EPRI continues to conduct research in BESS safety, and the current portfolio23 includes projects on thermal runaway off-gas characterization, propagation mitigation technolo- gies, characterizing risks of siting BESS near critical infra- structure, first responder training, and more. These activi- ties are done in collaboration with a variety of industry stakeholders including electric power companies, OEMs, fire departments, and other research organizations. Ongo- ing regulatory development, voluntary industry efforts, and focused research initiatives will continue to support increased BESS safety.
CONCLUSION
Industry efforts to improve BESS safety during a period of rapid deployment expansion have led to a sharp decrease in the failure rate, but areas of needed improvement remain. This analysis demonstrated that all stages of the product lifecycle contribute significantly to BESS safety and must be rigorously engineered and diligently tested. Notably, the data challenges the widespread assumption that the lithium ion battery cell is the primary cause of failure. The BOS and controls were the leading causes of failure, with the cell having a relatively small number of failures attributed to it. Finally, this analysis is limited by the data that is publicly available. Of the known incidents, less than a third were assigned a cause of failure due to lack of sufficient informa- tion. Industry transparency on details of BESS failures will be essential to more comprehensive analysis, to ongoing safety research, and to future development that will ensure the continued safe operation of BESS facilities.
23 Battery Energy Storage Fire Prevention and Mitigation Phase III. EPRI, Palo Alto, CA: 2023. 3002028531.
14 | EPRI White Paper 15256168
May 2024