Fire at world’s largest battery facility is a clean energy setback

A fire at the world’s largest battery storage plant in California destroyed 300 megawatts of energy storage, forced 1200 area residents to evacuate and released smoke plumes that could pose a health threat to humans and wildlife. The incident knocked out 2 per cent of California’s energy storage capacity, which the state relies on as part of its transition to use more renewable power and less fossil fuels.

The fire started the afternoon of 16 January, burning through a concrete building full of lithium batteries at the Moss Landing Energy Storage Facility in Monterey county, California. Other buildings on the site, including more battery storage facilities and a natural gas plant, were not affected. By the morning of 17 January, local officials reported minimal flames and smoke.

“This is really a lot more than a fire, it’s a wake-up call for this industry,” said Glenn Church, a member of Monterey county’s board of supervisors, during a press conference. “If we’re going to be moving forward with sustainable energy, we need a safe battery system in place.” After the press conference on the morning of 17 January, the blaze flared up again that afternoon, leading to an extension of the evacuation order.

Because lithium fires burn at high temperatures and emit toxic substances such as hydrogen fluoride, firefighters let this type of blaze burn itself out rather than engaging with it directly. There have been no reports of injuries associated with the fire, and air monitor systems did not detect any signs of hydrogen fluoride. But the smoke plumes from the fire are likely to have contained heavy metals and PFAS, better known as forever chemicals, says Dustin Mulvaney at San Jose State University in California.

Local officials are currently advising residents of Monterey county to stay indoors and keep their doors and windows closed. Inhaled heavy metals and PFAS could pose a health risk to area residents and farm workers. These substances could also impact wildlife such as the sea otters that live in the wetlands of the nearby Elkhorn Slough salt marsh, says Mulvaney.

The destroyed building was one of two Moss Landing battery facilities owned by the Texas-based company Vistra Energy. Its facilities previously experienced less serious incidents that involved overheating batteries and malfunctions in the fire suppression system. But the facility that went up in flames this week has a water-based suppression system and it is unclear why it failed, said Vistra Energy officials during the press conference. They are still investigating the root cause of the fire.

Despite this incident, utility-scale battery systems for electricity grids have experienced a 97 per cent drop in failures worldwide – which are often fire-related – between 2018 and 2023, according to a report by the Electric Power Research Institute, a non-profit organisation based in Washington DC.

“This massive decrease has been observed in spite of the fact that deployments of utility-scale storage continue to increase at high rates,” says Maria Chavez at the Union of Concerned Scientists. “Battery storage systems are designed with multiple levels of safety features that aim to prevent and mitigate issues like fire risk – unfortunately, accidents like the one at Moss Landing facility can still occur.”

California is also better prepared than most US states to respond to such incidents: it has a state law requiring local governments to develop emergency response plans with battery developers, says Mulvaney. He described the need to learn from events like this in designing future battery storage systems.

But the loss of most or all of the 300-megawatt facility at Moss Landing will put a serious dent in Vistra Energy’s overall 750-megawatt on-site energy storage capacity, and California’s total 13,300-megawatt energy storage capacity.

Moss Landing has been serving the state’s electricity grid by storing renewable energy and reducing dependence on fossil fuels such as natural gas plants, says Mulvaney. Reconstruction and building back battery capacity could take several years – a big ask, considering California is already facing the need for extensive rebuilding elsewhere due to the Los Angeles wildfires.

“We can’t have battery fires like this,” says Mulvaney. “We can’t lose 300 megawatts of batteries overnight like this.”