EPRI: battery storage failures per GWh fell 98% from 2018 to 2025

Serguey Asael Shinder09 October 2026, 07:472 min read

Annual failures of battery energy storage systems per deployed GWh fell 98% globally between 2018 and 2025, according to a new report from the US Electric Power Research Institute (EPRI), Risk Factors and Failure Statistics of Lithium-Ion BESS, released on 5 October and reported by Energy-Storage.news. EPRI corrected an early figure of 99% to 98% on 8 October. Over the same period deployment grew exponentially, passing 300 GWh of new installations in 2025.

How safe, in comparable terms. Drawing on its BESS Failure Incident Database, EPRI finds the failure rate of BESS units is now comparable to large oil-filled transformers, another utility asset with infrequent fires — and many incident-command and site-control practices for transformer fires apply to batteries too. For all recorded utility-scale incidents, no fire spread beyond the facility perimeter; 93% caused no injuries or fatalities; and no member of the public suffered acute injury from a BESS arc flash, fire or explosion. Since the 2019 Surprise, Arizona fire that injured four firefighters, there have been no reported US injuries or fatalities from BESS failures.

What drives risk.

• Indoor facilities are over-represented in incidents and sustain more damage when one occurs. EPRI recommends fire walls or barriers to segment large indoor sites and stop propagation, both within and between units — the lesson of the 2025 Moss Landing fire, a battery plant built inside a former turbine hall.
• Age and vintage matter: failure rates fall with newer designs, so EPRI recommends safety reviews and retrofits of early systems.
• Chemistry could not be isolated. Researchers could not separate cell chemistry from improvements in integration and operating practice, so they could not conclude chemistry alone is a risk factor for system failures.

The other side of the ledger. The same week, NextEra agreed to suspend two Long Island battery sites over possible water contamination from the suppression agent used in a 2023 incident — a reminder that consequences can outlast the fire. EPRI argues for data-driven thresholds for precautionary measures, so communities are not over-burdened, and for more transparency about failures. Its 2024 joint study with PNNL had put the decline at 97% for 2018–2023; the new figure extends the trend through a year of record deployment.

Source: Energy-Storage.news, "Global BESS failure rates declined 98% between 2018 and 2025", 8 October 2026 — https://www.energy-storage.news/global-bess-failure-rates-declined-98-between-2018-and-2025/