Smoke from fire at California lithium battery plant raises concerns about air quality

SAN FRANCISCO — A fire at the world's largest battery storage plant in Northern California smoldered Friday after sending plumes of toxic smoke into the atmosphere, leading to the evacuation of up to 1,500 people. The blaze also shook up the young battery storage industry.

The fire at the Vistra Energy lithium battery plant in Moss Landing generated huge flames and significant amounts of smoke Thursday but had diminished significantly by Friday, Fire Chief Joel Mendoza of the North County Fire Protection District of Monterey County said. Vistra is based in Texas.

''There's very little, if any, of a plume emitting from that building,'' Mendoza said. Crews are not engaging with the fire and are waiting for it to burn out, he said. Letting lithium-ion battery fires burn out is not unusual because they burn very hot and are hard to put out.

No injuries have been reported but residents raised concerns about hazardous gases being released into the air.

The fallout from the fire at the battery storage facility about 100 miles (160 kilometers) south of San Francisco was just beginning.

''This is more than a fire, this a wake-up call for the industry. If we're going to be moving ahead with sustainable energy, we need to have a safe battery system in place,'' Monterey County Supervisor Glenn Church said at a Friday morning briefing.

Battery storage is considered crucial for feeding clean electricity onto the grid when the sun is not shining or the wind is not blowing, and it has been used in significant amounts only in the last couple of years. But the batteries are nearly all lithium, which has a tendency toward ''thermal runaway,'' meaning it can catch fire and burn very hot, releasing toxic gases.

The blaze did not spread beyond the facility, according to Monterey County spokesperson Nicholas Pasculli. Evacuation orders for from 1,200 to 1,500 people were lifted Friday evening after officials confirmed there was ''no threat to human health,'' the Monterey County Sheriff's Office said in a statement. But residents were advised to close their windows and turn off their air conditioning.

''There's no way to sugar coat it. This is a disaster,'' Monterey County Supervisor Glenn Church told KSBW-TV.

Brad Watson, Vistra's senior director of community affairs, said the Environmental Protection Agency is testing air quality at the facility and that the company has hired an air consultant to check for pollution in nearby communities. Vistra will share the results when they are available, Watson said.

Kelsey Scanlon, director of Monterey County's Department of Emergency Management, told reporters that the release of hydrogen fluoride into the atmosphere from the blaze is a cause for concern.

The Centers for Disease Control and Prevention says hydrogen fluoride gas can irritate the eyes, mouth, throat, lungs and nose, and that too much exposure to the gas can be deadly.

''It doesn't appear that the fire department had the appropriate fire retardants to minimize this fire and have to resort to actually letting it burn, exposing all of the residents, including Watsonville in Santa Cruz County, and this is extremely disturbing,'' resident Silvia Morales said.

Monterey County Sheriff Tina Nieto said air quality monitoring systems had not detected any hazardous gases in the air.

Watson said two ''overheating events'' happened at the battery plant in 2021 and 2022 because the batteries got wet. A third incident happened in 2022 in the neighboring Elkhorn battery plant that is owned by PG&E, he said.

Lithium batteries make the power grid more stable and reduce the need for energy to be generated from fossil fuels, which release planet-warming gases. California was an early adopter of battery storage and leads the nation with more than 11 gigawatts of utility-scale storage online, which can meet nearly half of the demand on the state's main grid for four hours per day.

Experts say lithium batteries are a safe technology that are essential for lowering carbon emissions and making grids more reliable. But they are a significant fire risk if they are damaged or overheat.

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.

Jodie Lutkenhaus, professor of chemical engineering at Texas A&M University, said safer batteries must be found that can be used on the grid.

Some improvements, such as more fire prevention measures, can be made to reduce fire risks with lithium batteries, Lutkenhaus said, ''but the only way to really address the problem is to use a safer technology.'' Water-based and redox flow batteries are being developed by scientists but have not yet scaled commercially.

Lithium iron phosphate batteries are a possible alternative because they are highly stable, but they still carry some fire risk.

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