By Rob Nikolewski | rob.nikolewski@sduniontribune.com | The San Diego Union-Tribune
The San Diego County Board of Supervisors on Tuesday passed on the opportunity to establish interim safety requirements for battery energy storage projects, noting that county fire officials already have the authority to implement beefed-up guidelines.
San Diego County Fire Chief Tony Mecham said he was fine with the board's decision, especially since updates to statewide fire codes are coming in 2025.
"I think this is the best outcome so that we can still provide for safe projects," Mecham said after debate wrapped up at the County Administration Center downtown. "This is really emerging technology and I do think we need to reach out to people and get additional guidance."
Mecham said since at least five proposed battery storage projects in the county's jurisdiction are located in fire-prone areas, they will be subject to existing regulations requiring they have setbacks at least 100 feet from property lines to make sure crews have enough room to maneuver in case of fire.
County fire officials also recommended that the enclosures containing batteries be separated 10 feet from each other, but Mecham said the 10-foot rule is not set in stone.
Developers "may, for example, be able to cluster a couple of them together and create something like supermarket aisles and rows, where we still have access for our firefighters," Mecham said. "We'll look at each individual project" to determine what safety measures to impose.
Ten battery storage projects are under consideration in unincorporated areas of San Diego County in places such as Ramona, Valley Center, Bonita and East Otay Mesa.
Five of the projects in the pipeline are under the authority of the San Diego County Fire Protection District. The remaining five are under the jurisdiction of other fire districts in the county, who are free to set their own safety guidelines -- although Mecham has expressed hope that discussions can lead to one uniform standard throughout the county.
Battery storage is considered a crucial piece in California's policy goal of deriving 100 percent of its electricity from carbon-free sources by 2045. San Diego County has adopted a blueprint to reach net-zero by 2045 as well.
Storage systems take solar power generated during the day and discharge the electricity later, especially from 4 to 9 p.m. when the state's grid is under the most stress. Batteries can help reduce the risk of rotating power outages and replace natural gas "peaker plants" used during those critical hours when customers crank up their air conditioners.
But a spate of fires at battery storage facilities have broken out in the San Diego area in little more than a year.
The most recent occurred Sept. 5 in Escondido at San Diego Gas & Electric's 30-megawatt, 120-megawatt-hours facility that led to the temporary evacuation of about 500 nearby businesses. Crews from the city of Escondido found no abnormal readings indicating toxic fumes and air-quality monitoring did not indicate any health risks.
The largest fire broke out on May 15 in Otay Mesa at the 250-megawatt Gateway Energy Storage facility, operated by LS Power and its subsidiary, Rev Renewables. Fire officials said the batteries kept re-igniting and it took nearly 17 days before the last unit left the facility.
Battery fires can be difficult to put out. The lithium in most battery systems can experience "thermal runaway" -- a condition in which the batteries overheat, ignite and spread from one battery to another.
The Board of Supervisors on Tuesday debated adopting tougher safety requirements on an interim basis.
District 5 Supervisor Jim Desmond, who pushed to bring enhanced safety requirements before the board earlier this year, said, "I'm not against these (battery energy storage) projects, but they're catching fire and a danger is posed to homes and other sensitive areas."
Developers of battery projects and their supporters urged postponing a decision. The California Energy Storage Alliance, in a letter to the board, said several of the interim guidelines "are unworkable for the industry and pose a standard that is unachievable."
Board of Supervisors Chairwoman Nora Vargas said the interim rules "seem like overregulation, which I'm not supportive of," and proposed holding off discussion for 90 days.
In the end, the supervisors balked at implementing enhanced interim safety requirements and voted 3-1 to receive a 95-page technical study conducted by Jensen Hughes, an international consulting group that specializes in fire protection engineering.
They also adopted a recommendation that proposed battery projects are not subject to the California Environmental Quality Act known as CEQA because the board maintains the projects do not have a significant effect on the environment.
Among the proposals in the pipeline is the Seguro Energy Storage Project that Fortune 500 company AES wants to build on a 22.5-acre lot in Eden Valley, between San Marcos and Escondido.
If approved, the facility would generate 320 megawatts and 1,280 megawatt-hours of electricity that would flow to California's electric grid -- enough to power about 240,000 homes for four hours.
Joe Rowley, a retired engineer and Escondido resident who is opposed to the Seguro project, said Tuesday's meeting amounted to "an initial step in the right direction, but there's work to be done."
In an email, AES senior stakeholder relations manager Michael Huynh said, "We fully support San Diego County's efforts to prioritize safety without unduly impeding battery energy storage development in the county."