San Diego refuses call to ban battery storage projects
The Board of Supervisors of San Diego County, in California, has resisted calls for a temporary ban on new utility-scale battery energy storage systems (BESS).
A planning and land use session of the county authority, held on Sep. 11, 2024, opted against passing ordinances to bring in a moratorium on new BESS projects and to require all such sites to be based on modular, containerized design.
The local authority did, however, follow its chief administrative officer’s recommendation to continue to require all battery storage site applications to include details of fire safety properties related to project design, operation, and use, drawn up by a fire protection engineer.
Calls for a ban on new projects had been made in the wake of a 17-day battery fire at the 250 MW/250 MWH Gateway Energy Storage Station in Otay Mesa, San Diego, in May 2024. On Sep. 5, 2024, one of the 24 battery cells at a BESS belonging to utility San Diego Gas & Electric in Escondido caught fire.
Supervisors rejected the requirement all new BESS sites must be based on a modular design despite officers writing, in the meeting agenda, “BESS facilities are now largely using a modular design and are contained within enclosures (ie containerized facilities). This separates the battery units so that, should a fire occur, it is less likely to spread to other battery modules in the facility (ie thermal runaway propagation). This has reduced some of the fire risks of BESS facilities.”
Referring to the two recent battery fires, the agenda continued, “Unlike container battery projects, all the Gateway Energy Storage facility batteries were inside one rectangular warehouse building, allowing the fire to spread within the building and last for about 17 days. By contrast, the BESS facility in Valley Center, which included a modular design with enclosures to inhibit thermal runaway, had a fire that lasted around 45 minutes.”
Local media quoted calls from residents to bring in a moratorium on new sites, with reference to the 320 MW/1280 MWh Seguro project being planned by utility AES in the city of Escondido.
The NBC San Diego news site quoted a residents’ statement which said, “The Escondido battery fire is unfolding in an industrial area away from homes and residences. However, it reinforces the concerns of residents that a project that is 10 times larger (the Seguro project) is being proposed, which would be surrounded by hundreds of homes and upwind from a hospital in northern San Diego County, near Escondido.”
San Diego Board of Supervisors has funded a fire protection engineer to research BESS fire suppression and safety best practice, to inform safety standards. The results are expected by the end of 2024.