ESCONDIDO — A proposed battery energy storage facility near Escondido has some residents worried about its proximity to their homes, horses and other farm animals in the predominantly agricultural area.
AES Corporation, a global energy company focusing on developing green energy solutions, has proposed a BESS (Battery Energy Storage System) facility, known as the Seguro Energy Storage project, in the Eden Valley neighborhood near Harmony Grove, Escondido and San Marcos.
Eden Valley is known for its cluster of ranches that make up the community. The project is proposed to be constructed on 22 acres of land at 925 Country Club Drive, which was previously a horse reining arena before the land was sold to the energy company.
According to AES representatives, the project will provide a reliable and cost-effective power source to support the local electric grid. It also intends to help San Diego County meet its decarbonization goals and the state’s 100% carbon-free energy goals by 2045.
The project would feature 40-foot-long metal storage containers ranging between 8 to 10 feet in height that would house racks of battery modules meant for storing extra energy generated throughout the day and delivering it to homes during high-demand periods.
The system connects to the power grid from a new substation built on the project site to the nearby existing San Diego Gas & Electric Escondido Substation via an electric transmission line.
While not the first battery storage system in California or even San Diego County, the Seguro Energy Storage project’s 400 megawatts/1600 megawatt hours of stored energy capacity would be one of the largest in the state — enough to power nearly 300,000 homes in California for four hours.
Despite being touted as a green energy solution, many nearby residents feel the project isn’t as green as it may seem. In addition, many feel the project is too dangerous to be located next to so many homes and farm animals in a high-risk fire zone, pointing to other similar facilities catching on fire and exploding in the last few years.
Bill Osborn, a neighbor to the project and a former firefighter, said the proposed Seguro project is much closer to residential homes than the Elkhorn Battery storage facility in Moss Landing, Monterey County, where a Tesla Megapack was destroyed in a fire in September of last year.
Highway 1 was shut down and a shelter-in-place advisory was ordered during the blaze.
The Elkhorn battery storage facility and the proposed Seguro project hold lithium-ion batteries, notoriously difficult to extinguish due to high-burning temperatures and dangerous fumes.
AES officials presented information on the project to the San Dieguito Planning Group on April 13, where a room full of residents, including Osborn, shared their concerns about the project.
“To put this here would set a precedent,” Osborn said. “This would be the first of its kind.”
Osborn, who lives on Milpas Drive and shares a property line with the project, is worried about evacuating his home in the event of a disaster. He also noted that Palomar Hospital is within a kilometer of the project and could be shut down along with state Route 78 and the Sprinter rail system if a disaster occurred.
In 2019, a battery fire at the Arizona Public Service McMicken site in Surprise, Arizona, caused by a cascading thermal runaway event from an internal cell failure within one of the battery cells, injured several responding firefighters.
More recently, another fire broke out at another battery storage facility in Chandler, Arizona, in April 2022. The facility was owned by AES Corporation, the company proposing the Seguro storage site.
AES officials explained the new system at the proposed Seguro site will feature upgraded safety precautions, unlike the company’s previous facilities that experienced fires.
Max Guarniere, the project’s associate developer, said the battery management system equipped with 24-hour monitoring detects and isolates a fire in one of the containers by blocking it from the electrical power, closing off ventilation and dowsing the fire.
Each of the battery containers would also be spread out from one another to reduce the risk of a quick-moving conflagration.
“This isn’t one building where a fire could spread within,” Guarniere said. “We use a containerized solution so that in the unlikely event if a fire does occur, it will stay within one container.”
AES will also work with local first responders to develop an emergency response plan addressing evacuation and shelter concerns.
Regarding its proximity to nearby residents, AES officials said the site used land near existing electric grid infrastructure to minimize the need for overhead transmission lines.
The project is still in the early stages, with more public meetings. Currently, the developer is in its developing, siting and permitting phase and hopes to start construction sometime in fall of 2025. Once built, the facility’s operations are expected to commence in late 2025.
Before construction occurs, the project must develop an environmental impact report and receive final approval for its major use permit from the San Diego County Planning Commission.
CORRECTION: A previous version of this article incorrectly called an AES Corporation battery storage facility “Moss Landing battery storage facility.” The correct name is Elkhorn Battery storage facility in Moss Landing, Monterey County.