Homes and businesses within a quarter mile of the Valley Center Energy Storage Facility were evacuated and a shelter-in-place order was in effect for anyone a half mile from the site. Owner, Terra-Gen, issued a statement saying that the facility’s design systems are keeping the incident contained.

A fire erupted on Monday inside a solar battery storage container  at the Valley Center Energy Storage Facility in northern San Diego County, California.

The fire occurred when a battery storage unit caught fire, according to Terra-Gen, owner of the energy storage facility.

The Valley Center Energy Storage Facility is a stand-alone 139 MW energy storage project located on a 7-acre property within a commercial-industrial zone. Homes and businesses within a quarter mile of the site were evacuated and a shelter-in-place order was in effect for anyone a half mile from the site. Terra-Gen issued a statement saying that the facility’s design systems are keeping the incident contained.

The energy storage facility houses lithium-ion batteries in racks within enclosures. Electricity is stored and discharged from the batteries to the inverter transformer located next to them, which converts the energy from DC to AC. The energy is delivered to the SDG&E Valley Center substation located one-third of a mile away. Terra-Gen contracted with San Diego Gas & Electric (SDG&E) to provide power under a 15-year Resource Adequacy (RA) contract for up to 14,000 homes for four hours on a single charge..

Lithium-ion batteries have been known to cause fires, explosions, arc flashes, electric shocks from the energy storage systems can expose workers and area residents to toxic chemicals. The McMicken fire is an often cited incident that occurred in  2019 in Arizona when an Arizona Public Service (APS) battery failure and corresponding explosion left eight firefighters and one police officer hospitalized. Insights from that fire are reflected in the 2023 National Fire Protection Association (NFPA) 855 code revision. American Clean Power recently published a guide for first responders on lithium-ion battery energy storage system emergencies that takes the new code into account.

The Valley Center facility has been online since March 2022, and this is reportedly the second fire at the location. The first occurred in March of this year when a faulty sprinkler system caused the decommissioning of LG batteries.

The California Public Utilities Commission recently approved a plan to add more than 25.5 GW of renewables and 15 GW of storage by 2032, at a cost of $49 billion. The purpose of ramping up battery energy storage is to prevent power outages, help stabilize the grid, and help with peak power demand, all especially important in an area prone to high heat and wildfires. SDG&E is reportedly nearing approximately 300 MW of its own energy storage and Pacific Gas & Electric is also moving quickly to ramp up its battery resources.

According to Terra-Gen, the Valley Center project also provided economic benefits amounting to tens of millions of dollars in the form of direct and indirect jobs associated during construction and increased property taxes. In addition, the company donated $250,000 to support the Valley Center Fire Protection District’s new fire station.

Terra-Gen reports that it owns and operates four battery energy storage projects in California, representing over 1.5 GW of energy storage, or enough to power 1.5 million homes for approximately 4 hours. The company has an additional 1 GW under construction, expected to come on-line in 2025.