REGION — Residents of the Eden Valley and Harmony Grove neighborhoods continue efforts to prevent a massive battery storage facility from being built near their rural homes.
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 unincorporated Eden Valley just outside of Escondido.
If approved by the county, the project would be located on 22 acres at 925 Country Club Drive, previously a horse reining arena before the land was sold to the energy company.
While not the first battery storage system in California or even San Diego County, the Seguro Energy Storage project’s 400 megawatts or 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.
The project would feature 40-foot-long metal storage containers ranging from 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 project is still in its early design stage. According to AES officials, the latest permit application plot plan assumes that 230 battery storage containers will be onsite; however, this will likely change as the project design is optimized.
The system would connect 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.
Neighbors of the Eden Valley, Harmony Grove and Elfin Forest communities fear the project’s proximity to homes and Palomar Medical Center Escondido could fuel already dangerous local fire conditions if the facility caught ablaze.
“Lithium-ion batteries are constructed with flammable electrolytes and reactive lithium salts, which can generate a violent exothermic chemical reaction if the battery is damaged, overcharged or exposed to high temperatures,” said nearby resident Ashley Robertson Bedard via email. “The thermal energy generated by these reactions can cause a thermal runaway condition, which in turn enters a cycle of rapid increases in temperature and pressure within the battery, resulting in an explosion or fire.”
Many other residents, like Bedard, have voiced their concerns at previous information sessions held in 2023 and have created an online petition in opposition to the project. According to the petition, despite the project being touted as a renewable energy solution, its size, paired with only a 25-foot setback from current residential properties, is a problem.
The Elfin Forest Harmony Grove Town Council has also expressed its opposition to the project. Just recently, the council earmarked 50% of the approximately $10,000 in funds raised from its annual 5k/10k Elfin Forest trail run in early December to go toward stopping the proposed facility.
Town Council Chair JP Theberge said the county needs to have specific battery storage regulations in place before allowing the project.
“There’s no ordinance for lithium-ion battery storage facilities,” Theberge said.
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.
In terms of fire safety, Lead Project Developer Max Guarniere said the battery management system, equipped with 24-hour monitoring, detects and isolates a fire in containers by blocking it from the electrical power, closing off ventilation and dowsing the fire. The battery containers would also be spread out from one another to prevent the spread of fire.
In response to the concerns regarding Palomar Medical Center, Guarniere said the hospital is more than 1,600 feet from the eastern perimeter of the proposed battery storage facility and noted that another battery storage system and gas-fired power plant are already operating within a similar distance to the hospital.
“The Seguro facility’s design will meet the latest safety and design standards to ensure that, in the unlikely event of a fire, the hospital will be able to continue operating,” Guarniere said. “The facility will be equipped with robust monitoring and safety systems, including a fire suppression system at the battery module level, as the third stage of a four-stage approach to prevent fires from occurring, propagating or spreading.”
AES is also preparing fire protection and evacuation plans using emergency services and is working with the San Marcos Fire Protection District to prepare an emergency response plan in case of a safety incident.
According to Guarniere, AES selected the current site because the proposed use is consistent with the existing zoning, meets basic design requirements and avoids impacts on sensitive resources. The utility company spent more than two years researching and evaluating potential project sites with the necessary size requirements close to the SDG&E Escondido Substation, which serves as the point of interconnection to the electric grid.
“This process included evaluating the industrial parks in Escondido and the vacant land near Stone Brewing,” Guarniere said. “None of the available properties met the requirements.”
Joe Rowley, an Escondido resident and former power project developer who has also served as a consultant for identifying battery storage sites, was shocked when he learned about the proposed project and its location.
“I thought, ‘That can’t be right,’” Rowley said. “This location makes no sense to me.”
According to Rowley, the surrounding land use compatibility is the most important aspect of a project like this, which is why the project’s location is a problem given its proximity to nearby homes.
“To me, it’s appalling,” Rowley said.
The county has since begun the process of preparing a full environmental impact report for the project, which will include technical studies that address wildfires, hazardous materials, air quality and other potential impacts and mitigation measures to prevent such impacts.
The project must earn final approval for its major use permit from the San Diego County Planning Commission.
Guarniere said AES will continue to support county staff, expects to begin construction in early 2025 after obtaining all the necessary permits, and plans to hold a series of workshops focusing on specific topics like fire safety.
“We want to emphasize that there will be many opportunities for the community to ask questions, provide comments, and learn more before any final decisions on the proposed project are made,” Guarniere said. “We expect to host the first workshop early in 2024 and will share more information with the community once we have confirmed dates and locations for these workshops.”
