The San Diego County Board of Supervisors passed a measure on Sept. 11, 2024, for the county fire department, in coordination with a battery storage consultant, to complete a technical study examining potential safety standards for battery energy storage facilities. The study, which is expected to take about a month to complete, will be used to develop a uniform safety standard for battery storage projects. The standard is scheduled to come before the San Diego County Board of Supervisors on Dec. 11, 2024.
California has more battery energy storage system capacity than any other state. San Diego County alone is home to more than 50 battery energy storage system sites and has 10 energy storage projects in the pipeline. These battery storage facilities are integral to the state’s plan to achieve its climate goal of net zero carbon emissions by 2045.
However, in the past year, San Diego County experienced three fires at battery storage facilities. In light of the recent fires, one member of the board of supervisors stated that ordering the completion of the study is not enough and called for an immediate moratorium prohibiting battery storage operations in facilities that do not have isolated containers. The four other members on the board of supervisors disagreed, stating that, recognizing the energy and environmental benefits of the battery storage facilities, no standards should be adopted until the study is complete. Waiting until the study is released ensures the board of supervisors has the requisite information to adopt safety standards without unduly burdening and limiting the development of clean energy.
Attendees at the meeting on Sept. 11 expressed particular concern about a 23-acre battery storage site proposed by AES that could be built near residential neighborhoods in the Eden Valley area of Escondido. The facility, known as the Seguro Energy Storage project, would power nearly 240,000 homes with clean energy. The site was chosen for its proximity to existing industrial uses and an Escondido energy substation, which will make transmission of the stored energy easier and more efficient.
In response to public feedback, AES adjusted the project’s design and downsized the proposed battery storage system by 20%. It also increased the project’s setbacks so that it is located no less than 70 feet from the nearest structure and no less than 130 feet from the nearest home. Finally, AES added fire-resistant landscaping and fire hydrants, implemented stormwater capture solutions and developed a county trail along portions of the site. AES also committed to meeting or exceeding all required safety standards, including implementing a four-step fire mitigation plan that includes a battery management system for electrical diagnoses and system isolation; gas detection, smoke and sensor-triggered fire suppression systems; and fire suppression and containment systems within the battery containers — all of which will reduce the potential for and scope of a thermal runaway event.
California’s push for cleaner energy has led to an increased need for battery storage systems. Regulations specifying isolation measures or that restrict build locations could have significant impacts on the feasibility of future battery energy storage projects and could negatively impact the growth of clean energy infrastructure. With respect to this new and expanding battery storage technology, the greatest success and safety will likely be achieved in communities where there is open collaboration between state and local officials and battery storage facilities.