Moss Landing, the world’s biggest grid battery, caught fire again

Power company Vistra​’s flagship grid battery project, housed in and around a historic power plant dating back to 1950, erupted into flames Thursday night and prompted nearby residents to evacuate from Moss Landing, California.

The cause of the fire is not known, but local authorities have reported that much of the building that housed the batteries was destroyed as of Friday morning. That makes this by far the most destructive of the four battery fires that have afflicted the small coastal town since it became a linchpin in California’s clean energy overhaul. And the dramatic conflagration complicates the energy-storage industry’s efforts to win community support for more large batteries, which are seen as crucial to cleaning up the electrical system.

Canary Media Executive Director Eric Wesoff witnessed the disaster firsthand from his home about a quarter mile down the road. Around 3 p.m. Thursday, alarms went off and some smoke appeared at the power plant, he said.

“It didn’t seem as if it was a very big emergency,” Wesoff recalled. ​“Then, at about 6 p.m., it became a 100-foot-tall inferno type of affair with a black smoke plume. … It was apocalyptic, orange fire lighting up the night sky, the sound of engines starting, and people packing up their vehicles to get the hell out.”

At that point, an official in a pickup truck drove through the area and suggested that residents evacuate, Wesoff said. He drove away to safety, as did all his neighbors, and as of Friday afternoon, he still had not returned home.

The evacuation affected some 1,200 people, and shut down roads including a section of the fabled Highway 1, which runs south to Big Sur. Many residents of Moss Landing pick strawberries and other produce in the nearby farmlands, and can’t readily do their work away from home the way online workers can, Wesoff added.

The evacuation also affected a nearby clean hydrogen electrolysis facility operated by startup Verdagy.

Major battery hub suffers multiple fires

As California solar generation grew over the last decade, leaders and utility regulators recognized that the state would need to ramp up its battery capacity to shift daytime solar production into the valuable nighttime hours. The combination of solar plus batteries could finally help the climate-conscious state move on from its addiction to burning fossil gas to keep the lights on at night.

Moss Landing became the showpiece for this new battery era, due to its strategic proximity to the Bay Area, which needs a lot of electricity. Vistra owned a legacy coastal gas plant there, which provided a location and heavy-duty transmission-grid connections. The company pledged to turn it into an enormous battery to help utility Pacific Gas & Electric supply power to Silicon Valley and San Francisco.

Vistra installed 300 megawatts/1,200 megawatt-hours at the site in 2020, the largest project of its kind at that time. PG&E also built its own storage facility next door, a cluster of Tesla Megapack enclosures called the Elkhorn project.

Vistra later added a phase two with another 100 megawatts/​400 megawatt-hours. And it subsequently expanded the facility again, in 2023, to a total of 750 megawatts/3,000 megawatt-hours. For all three phases, the company used NMC batteries manufactured by South Korea’s LG Energy Solution.

“The Moss Landing project will enable the transformation of California’s energy system to more clean renewable resources, reducing greenhouse gas emissions while enhancing reliability of the power grid,” LG noted in a triumphal 2021 statement.

But a battery can only usher in a cleaner era for California’s grid if it remains operational, and Vistra’s Moss Landing suffered two fires in 2021 that shut it down for months. The Tesla Elkhorn battery had its own fire in the fall of 2022, but that only affected one Megapack enclosure and was quickly contained. In the risk-conscious world of battery development, limiting a fire to a single container counts as success — it means that project design and emergency response prevented propagation from one enclosure to the next. A single container is easy enough to replace.

The latest fire, at the building on Vistra’s property, did far more damage than any of the previous fires. This facility did not use containerized boxes, but instead repurposed the historic turbine hall as the home for rows and rows of batteries. Many of those appear to have converted into fuel, and the resulting combustion has destroyed most of the structure, per local authorities.

“This is a flagship, capstone installation, and Vistra has some explaining to do about why it’s become a serial offender,” Wesoff said.

Misconceptions abound in wake of battery fire

Several misconceptions have circulated in local news reports in the immediate aftermath of the Moss Landing fire.

First and foremost, a few reports erroneously conflated the fire on Vistra’s property with the Tesla Elkhorn facility. The facilities sit next door to each other, and both have indeed caught fire at different times, but the current disaster unfolded at Vistra’s battery facility, which was supplied by LG Energy Solution.

“The cause of the fire has not yet been determined, an investigation will begin once the fire is extinguished,” an LG representative told Canary Media in a statement. ​“LG Energy Solution will closely cooperate with our client and local authorities.”

Another line of commentary has focused on the fire response, or apparent lack thereof. As the flames shot higher into the night sky, the emergency responders did not deploy fire engines to hose it down. Instead, they let it burn out, which has taken a while, because there are so many batteries to burn.

To a layperson, this may seem like a nonsensical response to a fire. But the Monterey County fire service is the most experienced in the nation at handling large battery fires, given the previous three it has dealt with, noted battery-fire expert Nick Warner, co-founder and principal at the Energy Safety Response Group.

“‘Let it burn’ is a philosophical approach to managing an energy-storage incident that’s been around since 2019,” he explained in an interview with Canary Media on Friday. In 2019, firefighters in Arizona opened a battery enclosure that was experiencing a fire, and an explosion injured four of them. Since then, the industry has overhauled battery designs and response techniques to minimize risk to first responders.

“We like to say ​‘manage the incident,’” Warner added, since responders aren’t passively watching: They can actively manage a burning battery to reduce smoke and prevent fire from spreading.

“Once that fire got to the point where it was when the media coverage started, there’s essentially nothing the fire department can do at that point,” Warner said. ​“I don’t know if there’s enough water in the Pacific Ocean to spray on that building and manage that event.”

Faced with that impossible situation, ​“it seems like they were successful in keeping it contained and preventing injuries,” Warner noted.

A spokesperson for Vistra confirmed this to Canary Media: ​“All personnel were safely evacuated, and no injuries have been reported from either the initial incident or the ongoing response efforts.”

The disaster also represents a setback for the method of clustering batteries in a building enclosure instead of in modular containers, a common architecture for grid batteries. Warner cautioned against tossing out the whole category of purpose-built buildings to house grid batteries. The key, he said, was to ​“limit that fire load to something that is manageable.” That means cordoning off the batteries with physical barriers or distance, so that the total fuel available to a fire can’t get out of hand.

Clean energy developer REV Renewables employed this strategy at its Gateway project near San Diego, which caught fire in 2024. The design of that project helped contain the fire to one section, and firefighters were able to slow the blaze with water.