Start a Project → CALL
Close-up of rows of stationary battery cells with red and blue terminal caps in an equipment room
Home / Blog / Industry News
INDUSTRY NEWS

Battery Storage Failure Rates Are Down 98%. What the New Safety Data Means for Commercial Battery Projects in Southern California

October 22, 2026 · Burge Energy · 5 min read

Commercial battery storage safety got its clearest data point in years this month. On October 13, Utility Dive reported that the Electric Power Research Institute (EPRI) found the global failure rate of lithium-ion battery energy storage systems, measured per gigawatt-hour deployed, fell 98% from 2018 to 2025 and 50% from 2024 to 2025. pv magazine USA reported the 2025 rate at 0.04 failures per GWh deployed.

The timing matters in California. On September 18, battery modules at Vistra's Moss Landing plant in Monterey County flared up again, more than a year and a half after the January 2025 fire there, CalMatters reported. For owners in Orange County and across Southern California weighing a battery alongside solar or EV charging, the two stories raise fair questions: how safe is a modern commercial system, and what will the fire department ask for?

What the EPRI data shows for commercial battery storage safety

EPRI's report, Risk Factors and Failure Statistics of Lithium-Ion BESS, draws on the institute's BESS Failure Incident Database. Based on the reporting by Utility Dive and pv magazine USA, the key findings are:

  • What counts as a failure. EPRI counts large-scale thermal events (arc flash, fire, or explosion) from internal causes, not outside events such as wildfire, according to pv magazine USA.
  • Comparable to transformers. Stationary systems now show annual failure rates of 0.04% to 0.14%, which EPRI compares to about 0.1% for large oil-filled transformers, per Utility Dive.
  • Injuries are rare. Of the incidents EPRI reviewed worldwide, 93% caused no injuries or fatalities. EPRI reports no U.S. injuries or fatalities from battery storage failures since the April 2019 explosion in Surprise, Arizona, which seriously injured four firefighters, according to the UL Fire Safety Research Institute.
  • Why the rate fell. Much of the decline came from improvements made between 2018 and 2020 in design, codes and standards, battery management, and operating practices, pv magazine USA reported.

EPRI is candid about the limits. It notes that "limited transparency and data gaps remain a major challenge" to a complete database, per pv magazine USA. The trend is clear, but the numbers are an industry-wide average, not a rating for any one product.

Why the risk sits with older and indoor systems

The more useful finding for a buyer is where the remaining risk is concentrated. Older systems fail at higher rates than newer systems built under stricter codes, and facilities commissioned before 2021 make up about 3% of global storage capacity, according to Utility Dive. Indoor installations are overrepresented in U.S. failures and sustain more damage on average, according to Utility Dive, and EPRI recommends fire walls or similar barriers between units, pv magazine USA reported.

Moss Landing fits that pattern. Canary Media reported that the system was built inside a former gas turbine hall and used nickel manganese cobalt cells, while newer projects typically use spaced, modular containers and lithium iron phosphate (LFP) chemistry. Chemistry is not the whole story, though: EPRI could not determine whether chemistry alone is a system-level risk factor, because its effect is hard to separate from improvements in design and practice. Design, spacing, and controls matter as much as the cell. Vistra says the cause of the 2025 fire is still unknown, and CalMatters reported that a CPUC-coordinated root cause analysis is underway.

What California and local fire authorities now require

California has tightened battery storage rules on several fronts. Here is the status of each:

Many behind-the-meter commercial systems are smaller than that 10 MWh line, so their main reviewer is the local fire authority applying the California Fire Code. Local rules can go further than the state minimum. On September 17, 2026, the San Diego County Fire Protection District updated its battery storage guidelines for lithium-ion systems above 600 kWh. They apply the 2025 California Fire Code (effective January 1, 2026) and the 2026 edition of NFPA 855, and they require a hazard mitigation analysis, UL 9540A test results at the cell, module, and unit levels, and an emergency response plan. Fire suppression is required for systems inside buildings but not for outdoor enclosures that are not walk-in units. The guidelines are specific to that district, though other San Diego County fire districts may adopt them.

What this means for your project

The data suggests modern, code-compliant storage carries a low failure risk, and that design choices matter. Practical points for owners, developers, and facility managers:

  • Favor outdoor, listed enclosures where the site allows. Indoor systems bring more suppression and separation requirements, and the data shows indoor sites carry more of the risk.
  • Ask for test data early. Request the manufacturer's UL 9540A results at the cell, module, and unit levels before you commit to equipment, since local reviewers may require them.
  • Talk to the fire authority before you submit. A pre-application meeting surfaces access, spacing, and suppression questions while the design is still flexible.
  • Budget for the safety documents. Expect a hazard mitigation analysis and an emergency response plan for larger systems, and allow review time in the schedule.
  • Watch the size thresholds. Crossing a local threshold (600 kWh in the San Diego County district) or the state's 10 MWh line changes the review path.
  • Review older systems. If you own a system installed before 2021, ask about a safety review. EPRI's suggested retrofits range from adding gas detection to ventilation or structural upgrades, and some may void warranties, Utility Dive reported.

Incentive eligibility depends on project specifics. Confirm with your tax advisor and the program administrator before relying on any figure here.

How Burge Energy can help

Burge Energy designs and builds commercial battery storage, solar, and EV charging across Orange County and Southern California, for new builds and existing properties. We can help you choose a storage layout that fits your site and current fire code, coordinate early with the fire authority and utility, gather the test data and documents reviewers ask for, and screen your project for available incentives. Family-owned and building since 1977, Burge is licensed for solar, storage, and EV charging work. Request an Energy Assessment, learn more about Burge Energy, or review current programs on our Incentives page.

Sources

This article is general information, not legal, tax or financial advice. Facts are current as of October 22, 2026; rules and programs can change.

← All articles

Planning solar, storage or EV charging?

Request an Energy Assessment →Explore Burge Energy