A fire at one of the world’s largest battery-storage plants in northern California flared up again on Friday afternoon, sending up plumes of toxic smoke after authorities had said the blaze was mostly over.
The fire in Moss Landing in Monterey county started on Thursday, forcing the evacuation of up to 1,500 people and the closure of a major highway. Fire crews were not engaging with the fire but rather waiting for it to burn out on its own, a local fire official said.
The blaze was still burning on Friday but it had not gone beyond the facility, according to a Monterey county spokesperson, Nicholas Pasculli.
The Moss Landing Power Plant, located about 77 miles (125km) south of San Francisco, is owned by the Texas-based company Vistra Corp and contains tens of thousands of lithium batteries. The batteries are important for storing electricity from such renewable energy sources as solar energy, but if they go up in flames the blazes can trigger a chain reaction known as thermal runaway, which requires massive amounts of water to extinguish.
Lithium-ion battery fires are difficult to put out with water because they generate their own oxygen and release toxic gases such as hydrogen fluoride, which can be harmful if inhaled. “Even after the fire appears to be extinguished, there is a risk of re-ignition,” the San Bernardino county fire department explained last year after a truck carrying batteries crashed and caught fire. “The battery cells can remain hot and unstable for hours or even days.”
County health officials warned residents on Friday afternoon “to stay indoors, keep windows and doors closed, limit outdoor exposure, and turn off ventilation systems”.
“There’s no way to sugarcoat it. This is a disaster, is what it is,” Glenn Church, a Monterey county supervisor, told KSBW-TV. But, he said, he did not expect the fire to spread beyond the concrete building it was enclosed in.
The county board of supervisors held an emergency meeting on Friday morning to receive a briefing on the fire. “I can update that most of that fire burned out through the night,” the local fire chief, Joel Mendoza, said at the briefing.
Church, the county official, said at a news conference on Friday morning that the fire was not acceptable. “This is really a lot more than just a fire. It’s really a wake-up call for this industry,” Church said. “If we’re going to be moving ahead with sustainable energy, we need to have safe battery systems in place.
“This is the fourth fire at that site since 2019,” he added. “There are two battery operations going on there and both of them have had fires, and this has got to be the last one.”
Later on Friday, Church and California state lawmaker Dawn Addis told reporters that the fire had reignited and that they had called on the operator to keep the energy-storage facility offline “until it can be guaranteed as safe”.
Church is the author, with the journalist Kathryn McKenzie, of the book, Humbled: How California’s Monterey Bay Escaped Industrial Ruin, which tells the story of how local environmentalists, including Ansel Adams, blocked the proposed construction of a huge Humble Oil refinery in Moss Landing in the 1960s.
The evacuation orders were lifted late on Friday by the Monterey county sheriff’s office following what it called an assessment by environmental agencies that there was “no threat to human health” from the smoke above the area. However, another agency, the Monterey Bay Air Resources District, sounded a more cautious note, pointing out that it lacks the ability to track a key toxin.
“It should be noted that MBARD does not have the capability to test for hydrofluoric acid (HF), a toxic air pollutant of concern associated with battery fire emissions from lithium battery fires,” the agency said in a press release. “HF is a highly reactive gas that can readily react with water to form hydrofluoric acid, which can further react with other substances in the environment, impacting its mobility and toxicity.”
There were fires at the Vistra plant in 2021 and 2022 that were caused by a fire sprinkler system malfunction that resulted in some units overheating, according to the Mercury News.
It was unclear what caused this latest fire. Vistra said in a statement that after it was detected, everyone at the site was evacuated safely. After the fire is out, an investigation will begin.
“Our top priority is the safety of the community and our personnel, and Vistra deeply appreciates the continued assistance of our local emergency responders,” Jenny Lyon, a spokesperson for Vistra, said in a statement.
North Monterey county unified school district announced that all schools and offices would be closed on Friday due to the fire.
Associated Press contributed reporting