One year after a stubborn battery fire broke out at the Gateway Energy Storage facility in Otay Mesa, the site has not returned to its previous level of output.
Emergency crews responded on May 15, 2024, to a blaze centered in Building 3 of the 250-megawatt facility that houses batteries that help supply California’s power grid with zero-emissions electricity.
After the fire appeared to be extinguished, the Nickel Manganese Cobalt batteries kept reigniting and it took nearly 17 days before the last fire fighting and air monitoring crews from San Diego Fire and the Sheriff’s department left the site. No injuries or damage to nearby properties were reported.
REV Renewables, the New York-based company that owns 100% of Gateway Energy Storage, said later it had launched a root-cause analysis into the fire.
Responding to a list of questions from the Union-Tribune about the status of the Gateway site now that a year has ed, a representative from REV Renewables said in an email that the Otay Mesa facility “is partially operational.”
The spokesman did not elaborate, beyond saying, “We completed a thorough testing of all the batteries at the facility and have returned a subset of them to service after close coordination” with a unified command team.
Formed at the time of the fire, the team is a combination of federal, state and local agencies that includes the U.S. Environmental Protection Agency, Cal Fire and the San Diego County Environmental Health Hazardous Incident Response Team.
The REV Renewables spokesman said the cleanup is still “ongoing” but did not supply a timeline for when the efforts expect to wrap up, nor what the root-cause analysis has found thus far.
“Safety has been and will remain our No. 1 priority as we continue to work closely with authorities and all stakeholders to complete the complete the cleanup and eventually bring the facility back to full capacity,” the email said.
According to a post on the EPA website, the removal of the damaged batteries is expected to continue until mid- to late summer 2025.
The REV Renewables spokesman did not say if the Otay Mesa site will use different types of battery chemistries when it fully reopens.
In an email shortly after last year’s fire, the company said the Gateway facility consists of seven buildings and about 6,700 racks of batteries.
Considered a key piece of California’s target to derive 100% of its electricity from carbon-free sources by 2045 or earlier, the number of battery storage facilities across the state has boomed.
Commonly stacked in rows, batteries take electricity that’s generated during the daytime hours from solar, store that energy and send it to the electric grid in the evening.
Electricity from batteries — which emit no greenhouse gases — can offset power that would otherwise be supplied by fossil fuel generation such as natural gas, while also enhancing grid reliability during those hours.
On Monday, Gov. Gavin Newsom announced California added 2,300 megawatts of battery storage to the state’s grid since September. For perspective, California’s last remaining nuclear power plant, Diablo Canyon, generates 2,240 megawatts of electricity.
The state’s battery energy storage portfolio has jumped from just 700 megawatts in 2019 to 15,763 today.
“The key to a cleaner, more reliable power grid is batteries — and no other jurisdiction on the planet, save China, comes even close to our rapid deployment,” Newsom said in a statement.
But all the growth has some people nervous.
In September, a fire ignited inside a 30-megawatt San Diego Gas & Electric battery facility in Escondido. That led to the temporary evacuation of about 500 nearby businesses. Crews from the city of Escondido found no abnormal readings indicating toxic fumes and air-quality monitoring did not indicate any health risks.
In an email to the Union-Tribune, an SDG&E spokesperson said the facility is still offline but the company plans to eventually resume operations. As at Gateway, the Escondido facility used nickel manganese cobalt batteries.
“Alongside independent experts and regional authorities, we are working carefully to understand the incident fully,” the SDG&E spokesperson said. “We are committed to sharing findings once the investigation concludes and will implement any necessary measures to further enhance the safety and reliability of our systems.”
In January, a fire broke out at a 750-megawatt facility containing 99,000 LG battery modules in the Northern California community of Moss Landing that sent toxic gas into the air and led to the evacuation of about 1,500 residents. The blaze burned for two days and closed a section of Highway 1 for three days.
The plant’s owner, Texas-based Vistra Energy, and emergency responders are still looking into what caused the batteries to ignite.
Battery fires can be difficult to put out. The lithium in most battery systems can experience “thermal runaway” — a condition in which the cells overheat, ignite and spread from one battery to another.
“I think there’s a big move to sort of downplay all these things, that’s it’s no big deal,” said JP Theberge, who lives in the Elfin Forest community near Escondido and opposes constructing battery facilities near homes, schools and hospitals.
“The bottom line is safety. People want to feel safe and I think anyone who has one of these things next to their house is not feeling safe,” said Theberge, who is a member of Californians for Safe Energy Storage.
But backers of battery storage say safety standards keep getting better.
“The industry has matured significantly since some of those older systems were installed,” said Scott Murtishaw, executive director of the California Energy Storage Alliance.
At Gateway and Moss Landing, for example, the batteries were enclosed inside a building, while batteries in newer facilities are more likely to be placed in modular containers that are easier to monitor and have reduced risk of thermal runaway.
“The way that we’re deg the systems is just inherently safer, with different chemistries and the containerized configurations,” Murtishaw said. “Because of that, you will literally never see another fire like Moss Landing again.”
Nickel manganese cobalt batteries are the most popular lithium-ion battery chemistry in the electric vehicle industry (outside of China) and have been used in grid-tied storage facilities.
But lithium iron phosphate batteries — known as LFP, with the F standing for iron — have recently grown in popularity because they cost less and are considered more fire-resistant. While individual NMC cells are energy-dense, the higher degree of safety of LFP means the cells can be packed more tightly together.
