1,500 Charged Batteries Ignite Inside Damaged Moss Landing Facility

MOSS LANDING, Calif. — Vistra Corp.’s Moss Landing Energy Storage Facility began operating its 300-megawatt Phase I installation in December 2020, making it one of the earliest mega-scale battery projects in the world. A 100-megawatt Phase II expansion followed in 2021, and a 350-megawatt expansion was added in 2023, bringing the complex’s total potential capacity to 750 megawatts (3,000 megawatt-hours). The facility occupies the site of a former natural gas-fired power plant along the Monterey Bay coastline near Elkhorn Slough.

On Friday morning, 1,500 fully charged lithium-ion batteries spontaneously ignited inside a decommissioned structure at the facility. The structure had already been severely damaged during a major fire in January 2025, and the new incident triggered emergency response protocols and temporary shelter-in-place orders in Monterey County.

The facility has faced other disruptions since its commissioning. An overheating event in the Phase I building in September 2021, caused by a failure in the water suppression system, led to a localized shutdown. A secondary water suppression leak produced a similar outage in the Phase II building in February 2022. In September 2022, a separate fire struck PG&E’s neighboring 182.5-megawatt Elkhorn Battery Energy Storage System, which uses Tesla Megapacks on an adjacent Moss Landing property.

Cal Fire and the North Monterey County Fire Protection District were dispatched to the highway-side facility at approximately 6:15 a.m. Friday after receiving reports of a structure fire. The facility was evacuated immediately following the initial dispatch, and local authorities said no plant personnel or emergency responders were injured.

Fire officials established precautionary safety zones and advised nearby residents to shelter in place, close all windows and doors, and turn off heating and air conditioning units to prevent external air from entering. By 10:30 a.m., shelter-in-place advisories had been lifted for most of the surrounding area, although restrictions remained in one designated zone directly next to the site.

The batteries had remained fully energized even after the building was disconnected from the electrical grid following the January 2025 fire, Cal Fire Public Information Officer Josh Silveira said. At a noon joint briefing, North Monterey County Fire Protection District Chief Jess Cortez said approximately 1,500 fully energized batteries were positioned against the building’s north wall.

Hazardous materials crews and salvage technicians had been systematically disconnecting and removing the units, but the work stopped after structural degradation raised concerns that the north wall could collapse on workers. While crews awaited structural stabilization, the un-isolated batteries spontaneously combusted, Cortez said.

“At this particular point in the incident, there is no active fire,” Cortez stated during the briefing. “It is hot, smoldering at this particular point, but the incident is still within a scope that it could decrease or continue going.”

Cortez said Friday’s incident was substantially smaller in scope and operational complexity than the massive fire at the facility nearly two years earlier. That blaze forced roughly 1,200 area residents to evacuate, halted traffic along California State Route 1, and required days of continuous monitoring to suppress.

Specialized teams from the U.S. Environmental Protection Agency (EPA) and the Monterey Bay Air Resources District deployed mobile sensor arrays around the Moss Landing perimeter. They monitored combustion byproducts, with environmental health officials focusing on fine particulate matter (PM 2.5) and hydrogen fluoride, a corrosive gas generated when lithium-ion cell electrolytes undergo thermal runaway reactions.

At noon, officials reported that off-site emissions remained below public health screening thresholds. “There’s a few [sensors] that have edged into moderate air quality, but we expect those probably to go back to green as we get better wind flow through there,” said Richard Stedman, air pollution control officer for the Monterey Bay Air Resources District. “Basically, we’re not seeing anything that indicates that there’s a problem with air quality and would result in exposure at the facility at this time.”

The recurring Moss Landing fires come as California expands energy storage under Senate Bill 100, enacted in 2018. The law requires 100% clean, zero-carbon electricity for state end-use by 2045. Battery capacity has grown from less than 500 megawatts on the state grid in 2020 to more than 10,000 megawatts as California accommodates intermittent solar and wind power and manages evening peak demand through the California Independent System Operator (CAISO).

Since the early Moss Landing phases were built, energy-storage engineering standards—including National Fire Protection Association (NFPA) Standard 855 and updated UL safety certifications—have developed rapidly. The standards place greater emphasis on explosion venting, physical cell separation, and localized thermal containment.

Cleanup and hazardous material mitigation at the damaged Moss Landing structure will resume after local fire authorities confirm that internal temperatures have stabilized and structural integrity risks have been addressed.