Officials reported Saturday that they are “cautiously optimistic” that the worst has passed following a large fire that broke out Thursday afternoon, consuming the majority of the Vistra storage plant in Moss Landing.
About 80% of the plant, and the lithium batteries it housed, were consumed in the fire, said Joel Mendoza, chief of the North Monterey County Fire Department, at a Saturday press conference. The plant, located across from Moss Landing Harbor on the site of a former PG&E power plant, holds tens of thousands of lithium batteries. Such battery fires are notoriously difficult to extinguish, can burn at high temperatures and emit toxic gases that can cause respiratory problems, skin burns and eye irritation.
As of 2 p.m. Saturday, the flames were out and the smoke had died down, but heat remained inside the structure. And, because it’s normal for battery fires, in particular, to intensify again, first responders continued to keep U.S. Highway 1 closed in both directions between Highway 183 and Struve Road, officials said There was no estimated time to reopen Highway 1.
“The last thing we need is the public getting in the way of emergency services trying to do their job,” said Monterey County Sheriff Tina Nieto.
Federal officials are monitoring the air quality in addition to Vistra’s roaming air quality monitoring efforts, said Olivia Trombadore, onsite coordinator for the U.S. Environmental Protection Agency. The agency set up nine air quality monitors the first night after the fire broke out to check for hydrogen fluoride and particulates, two contaminants that can pose health risks, in and around the fire site and evacuation area. Their models indicated that hydrogen fluoride, an acidic gas that is hazardous to inhale, would have been consumed in a fire of the size that occurred, she said.
“We have not seen any levels of these two contaminants that would pose a threat to the public,” she said.
A majority of residents living near the Vistra storage plant in Moss Landing returned home Friday night, officials said, just hours after an evacuation order was lifted.
Monterey County spokesperson Nicholas Pasculli said the exact number of residents who returned are unclear. In a Friday night update, the Monterey County Department of Emergency Management said the air quality monitoring confirmed “no threat to human health.”
The conflagration raises questions about the safety of a technology — battery storage — that is considered important for supporting California’s expanded use of solar and wind energy in the long term. In the past years, the state has been increasingly reliant on huge battery storage plants to capture electricity during the daytime and release it on the grid at night to reduce the risk of blackouts during hot summer months, when demand is high.
County Supervisor Glenn Church and Assemblywoman Dawn Addis called on Vistra to provide greater safety assurances to the public when it comes to its roughly $1 billion battery storage facility.
“We need to make sure that when we say to a community, ‘We are working on climate solutions,’ we are not saying ‘We are doing that, but it’s on the back of your health and safety,” Addis said, calling for a full investigation of the fire.
“We will put the best technology and the best human minds to work to make sure that we can get the highest probability it won’t happen again,” said Vistra Senior Director of Community Affairs Brad Watson.
The fire was reported Thursday afternoon, when alarming plumes of black smoke billowed from one of the world’s largest battery storage plants. The event closed Highway 1 and evacuate residents in Northern Monterey County, from areas of Moss Landing south of Elkhorn Slough, north of Molera Road and Monterey Dunes Way, and west of Castroville Boulevard and Elkhorn Road to the ocean.
Fire crews did not engage with the fire, which was contained to the site, but let it burn out on its own. The flames continued to flare through Thursday and smoldered into Friday. Evacuation orders were lifted at about 6 p.m. Friday night, with officials advising returning residents to stay indoors, limit outdoor exposure and turn off their ventilation systems.
Monterey officials said Friday that they had been misled by Vistra, the Texas-based energy giant that built the 750-megawatt plant in 2020.
Mendoza said Vistra’s fire suppression system, which had worked in prior situations, wasn’t sufficient, and the fire overtook the system. He added that air quality monitors set up by officials from the U.S. Environmental Protection Agency had not detected hydrogen fluoride gas, one of the main hazardous materials that can come from burning batteries.
A county hotline at 831-769-8700 has also been established for residents to call officials with any questions about the air quality and best practices for keeping safe, Pasculli said.
Staff writers Paul Rogers and Molly Gibbs contributed to this report.