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The burned remains of the Moss Landing Power Plant battery energy storage facility caught fire again Friday morning, prompting Monterey County officials to issue a shelter in place order — less than two years after it became one of the largest battery storage facility fires in history.
Workers for Vistra, the plant’s Texas-based operator, noticed a flare-up early Friday morning against the wall of a building that burned in the initial January 2025 fire. The cause: roughly 1,500 inaccessible battery modules, still charged, spontaneously ignited, said Chief Jess Cortez with the North County Fire Protection District.
“They’re in the smoldering stage right now,” Cortez said at a briefing Friday afternoon, adding that at that point there was no active fire. “The incident is very dynamic. There could be possible flare-ups.”
Local authorities lifted the order to shelter in place later Friday afternoon. Still, the flare-up reignites fears about battery storage facilities — even as California comes to increasingly rely on them. The state now has “the nation’s largest battery energy storage fleet,” the California Energy Commission announced in August.
“If we had only known the worst-case scenarios of how not to build batteries, we wouldn’t have built Moss Landing,” said Dustin Mulvaney, a professor at San Jose State University in the school of planning, policy and environmental studies. “Because it keeps coming back to haunt us.”
The incident also sharpens the tension between Gov. Gavin Newsom’s push to shortcut permitting for energy and other projects, and the communities hosting these facilities.
Fire, rekindled
In January 2025, residents watched large plumes of smoke and ash spewing from Vistra’s 300-megawatt battery energy storage facility at the Moss Landing Power Plant in Monterey County.
It was the facility’s fourth safety incident, the third on the Vistra property, since 2019, according to a letter Assemblymember Dawn Addis, a San Luis Obispo Democrat, sent state regulators last year. The fire continued for days before crews could control it, then rekindled briefly a month later.
Newsom called for a state investigation. The California Public Utilities Commission began with a site visit that month.
Nearly two years later, that investigation is ongoing, with a root cause analysis underway in coordination with Vistra and an independent consultant, said Terrie Prosper, a spokesperson with the Public Utilities Commission.
Monterey County Supervisor Glenn Church expressed frustration about the delay.
“Why it takes a year and a half to come up with an answer when everything is just about near the end of being cleaned up, I don’t know,” he said.
Before the state approves any more of these facilities, he said, “It’s a good idea to know what’s causing these fires.”
Safety rules, too late
Unlike facilities built more recently, the Moss Landing site was built in an enclosed, aging building with older battery technologies crammed closely together — allowing fires to spread quickly, Mulvaney said.
Denise Grab, the Clean Energy Law & Leadership project director for the Emmett Institute on Climate Change and the Environment, agreed: The site is “one of the earlier battery storage facilities in the state and in the country, even. And the design is not up to par with current safety designs.”
Battery plants still carry less overfall harm than fossil fuel plants, Grab added.
“There are risks from other types of energy generation as well, particularly fossil fuel,” Grab said. “Asthma, premature death, heart attacks, lung disease from fossil fuel plants is significant, and (battery plants pose) a different kind of risk.”
California passed a series of safety laws both before and after the January 2025 fire, including several laws from State Sen. John Laird, a Santa Cruz Democrat, aimed at better planning for — and preventing — fires.
A 2022 law by then-Sen. Ben Hueso required the California Public Utilities Commission to set new standards for battery storage facilities and boost oversight of their emergency plans. But the commission didn’t bring its proposal for implementing Hueso’s law to a vote until after last year’s Vistra fire.
“We should have never built Moss Landing the way we did,” Mulvaney said. “We were too late with coming up with the standards and certifications, which make batteries much safer today.”
Environmental health controversy
Vistra says that the cause of last year’s fire is still unknown. The energy company commissioned a study finding that chemical concentrations in nearby soil or water posed no risk to humans or the environment.
“As a result, no further human health or ecological risk evaluation related to the (Moss Landing fire) event is warranted,” the report read.
But scientists’ findings and resident accounts suggest otherwise. As the fire blazed for days in January 2025, residents reported wheezing, coughing, headaches and eye irritation.
Researchers presented additional findings at a symposium last month, including evidence from one UC Santa Cruz researcher of elevated exposure to battery-related materials in hair samples.
Scientists with the San Jose State University’s Moss Landing Marine Laboratories have found high levels of nickel, manganese, and cobalt in soil around the facility. Ivano Aiello, the scientist who led the study, said Vistra’s recent report examined potential contaminants months after the fire was contained.
The long-term health impacts of potential exposure remain unclear, and researchers continue studying the incident.
Richard Stedman, an Air Pollution Control Officer with the Monterey Bay Air Resources District, said regulators placed four monitors at the fence line around the Vistra facility, and two more nearby: None detected unhealthy levels of particulate matter as of Friday’s briefing.
Brian Roeder, founder of the community group Never Again Moss Landing, said the public’s trust in regulators and politicians who are meant to protect them continues to erode.
“We’ve had 20 months to prepare for this,” he said. “Here we are again, right back where we were before, knowing this could happen.”
