Energy storage failures drop 98% as legacy systems remain vulnerable

Battery system failures fell 98% between 2018 and 2025, but older installations still require specialized maintenance to avoid risks.

Energy storage system failures decreased by 98% between 2018 and 2025 according to EPRI’s analysis of its BESS failure incident database. Annual failure rates for stationary systems now range from 0.04% to 0.14% per GWh, a dramatic improvement from earlier periods. This progress follows a 50% reduction in failure rates between 2024 and 2025, and no U.S. injuries or fatalities occurred from BESS failures since April 2019.

The reliability gains stem from EPRI’s tracking of safety incidents and the adoption of NFPA 855 as the key standard for battery facilities. However, older systems remain problematic: BESS facilities commissioned before 2021 account for 3% of global capacity, and indoor installations fail at higher rates than outdoor ones. The January 2025 Moss Landing incident—a 300-MW battery array destroyed by thermal runaway in a 1950s-era turbine hall—demonstrates why legacy infrastructure needs special care.

This trend lowers renewable energy costs and reduces blackout risks by making grid storage more dependable. Yet it creates friction: the 3% of pre-2021 systems still require targeted maintenance to avoid failures like Moss Landing’s. Without addressing these aging assets, the 98% reduction in overall failures won’t translate fully to universal grid resilience.

What to watch: How quickly utilities retrofit legacy systems under NFPA 855, and whether the Moss Landing incident’s root cause (decommissioned thermal plants) becomes more common. Caveats include failure rates reported per GWh and the Moss Landing site being a decommissioned facility.

Source: Utility Dive