It Took More Than 4 Days to Put Out This Battery Fire

A fire at a battery storage site in San Diego County appears to have been extinguished after burning on and off for multiple days and nights.

“There is no visible smoke or active fire at the scene,” Cal Fire, the state fire protection agency, said in an update Monday morning .

The fire started sometime Wednesday at the Gateway Energy Storage facility, a 250 megawatt battery electric storage system in Otay Mesa, which is immediately adjacent both to the eastern border of San Diego and to the northern border of Mexico and near the Richard J. Donovan state prison facility.

Firefighters first succeeded in putting out the blaze on Thursday, “but a flare-up later that night brought firefighters back to the scene,” the San Diego Union-Tribune reported . Firefighters continued working on the flames all weekend. As late as Sunday, there were 40 firefighters at the scene, according to Union-Tribune reporters .

Gateway’s owner and operator is LS Power, which has not responded to a request for comment as of publication time. LS Power operates several battery electric storage facilities in both California and New York. Gateway went into operation in 2020, as did many battery storage projects in California . Its purpose is to charge when energy is cheap or when there’s plentiful solar power so that it can deliver that excess energy back to the grid at times of high demand.

Fires have been a recurring problem for the battery electric storage industry, which may be one reason why, according to Heatmap polling , it is the form of carbon-free power least popular with the general public. Firefighters need specific training to deal with battery fires, and “ thermal runaway ” — i.e. one cell overheating and igniting leading to another cell doing so and so on — can mean that fires last for several days at very high temperatures.

On Saturday, Cal Fire reported that “lithium batteries continue to experience thermal runaway,” and that the fire had “burned through part of the roof.” As of now, fire personnel are “on standby in case additional batteries undergo thermal runaway.”

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