Monterey County officials call Moss Landing lithium battery storage fire a ‘wake-up call’

Monterey County officials declared a local emergency after a fire ignited at a power plant and one of the largest lithium battery storage facilities in the world last week, releasing a large plume of toxic smoke into the air and raising questions about the safety of the clean-energy storage industry.

Roughly 1,200 people were ordered to evacuate their homes for more than 24 hours as a section of the Moss Landing Power Plant burned. The plant is about 18 miles northeast of the city of Monterey and has been the site of three other fires since 2019.

County officials are demanding it remain closed until the cause can be investigated and corrective action taken.

The fire, which ignited Thursday, burned for two days before starting to cool down Saturday, at which time about 80% of the building and 80% of the batteries stored inside the facility had been destroyed, said Joel Mendoza, chief of the North Monterey County Fire Protection District, at a weekend news conference.

The U.S. Environmental Protection Agency conducted extensive air quality monitoring around the plant and did not detect any threat to public health during the incident.

“Results for hydrogen fluoride and particulate matter showed no risk to public health throughout the incident, and smoke from the facility has greatly diminished,” the agency reported Monday.

Nevertheless, residents and politicians who represent the region remained on edge.

The plant is a natural-gas-powered electricity generation plant near the Moss Landing Harbor in an unincorporated area of Monterey County. The lithium ion batteries stored at the site can release toxic gases if ignited. Experts say that includes heavy metals and perfluoroalkyl and polyfluoroalkyl substances, known as PFAS, which the EPA says are “widely used, long-lasting chemicals, components of which break down very slowly over time.”

“While battery storage is essential to the future, we cannot put that above safety,” Monterey County Supervisor Glenn Church said in a statement Tuesday. “This technology is ahead of government’s ability to regulate it, and industry’s ability to control it.”

On Tuesday, the county Board of Supervisors unanimously approved Church’s motion to send a letter to Texas-based Vistra Energy, which owns the plant, and to the Pacific Gas and Electric Co. requesting that they not bring the battery system online until the cause of the fire had been determined and addressed with corrective action.

Church has also said the fire raises important questions about whether the plant should be located near an environmentally sensitive area. The Elkhorn Slough estuary sanctuary is nearby.

“I think this is best described as a worst-case scenario disaster that’s happened here,” Church said during a Friday morning media briefing. “This is really a lot more than just a fire — it’s really a wake-up call for this industry.”

During an emergency briefing at the county Board of Supervisors meeting on Friday, officials said the fire mostly burned out, but there was a plume released from the plant that contained hydrogen fluoride, a toxic compound that by evening was pushing north from the plant, according to county spokesperson Nick Pasculli.

“It appeared last night and early this morning that the plume was reaching elevations where it might not endanger the human population,” Pasculli said.

Brad Watson, senior director of community affairs at Vistra Energy, apologized Friday for the effect the fire had on the community.

“Our company takes very seriously what happened last night, and we are hurting today, because we know primarily it’s impacted and disrupted the people who live around our site, our neighbors, our friends and businesses, and for that, we are sincerely sorry,” Watson said during a news briefing.

The company said Friday that it planned to hire an outside consultant to check the air quality and safety.

Church compared the fire with the partial nuclear meltdown at Three Mile Island in Pennsylvania in 1979.

“If renewable energy is going to be the future, it really needs to rest in safe energy,” he said.

Several factors contributed to the spread of the fire and complicated the response carried out by firefighters, Mendoza said Friday.

A fire suppression system that is part of every battery rack at the plant failed to keep up with the fire.

“It was overridden, and that led to the fire overtaking the system and eventually overtaking the entire building,” Mendoza said.

Firefighters arrived around 3 p.m. to find smoke coming out of a building and at least one battery on fire, according to Mendoza.

The Fire Department requested help from the county and other agencies when it confirmed that lithium batteries were on fire. But several factors hindered its response, including a camera system in the plant that was not working and superheated gases.

Once the fire began spreading, firefighters were not able to use water, because this can trigger a violent chemical reaction in lithium ion batteries, potentially causing them to catch fire or explode.

“In this particular case, we had X number of batteries that burnt, but we had some batteries that did not burn, and had we introduced water into that area — they were going to become unstable and then possibly burn,” Mendoza told local news station KSBW-8.

The public was notified early on during the incident, Mendoza said, and local highways were closed. Evacuation orders were issued for residential areas near the plant around 6:30 p.m. Thursday and lifted at 6 p.m. Friday.

There were no reports of any injuries.

Dustin Mulvaney, a professor of environmental studies at San José State University, is working on a research project about the life cycle impacts of lithium batteries and energy storage systems.

Mulvaney is interested to know what Vistra Energy has learned from the previous fires at the plant and how that has informed its preparedness in the event of an emergency.

He agrees that the fire should be a wake-up call for the industry to work together and figure out how safety measures can be improved. But this isn’t the first time a fire has forced Monterey County to respond to a potential disaster.

In 2023, the state signed into law Senate Bill 38, which requires battery storage operators to develop a plan in the event of an emergency. That was in response to a September 2022 fire at the Elkhorn Battery Storage Facility in Moss Landing.

Mulvaney doesn’t expect the battery storage projects in California to slow down, but it doesn’t look good for the industry.

“The question for California is: What did we get wrong?” Mulvaney said. “How can we better regulate the design and safety of these things?”