SAN MARCOS — The San Marcos City Council adopted new guidelines for battery energy storage system facilities this week as residents continue to share concerns about proposed projects in North County.
The guidelines, adopted Tuesday, apply to all new and existing battery energy storage system projects, or BESS, exceeding 600 kilowatt hours within the San Marcos Fire Protection District. Requirements were developed to align with California Fire Code and National Fire Protection Association standards.
BESS facilities have been identified as a crucial means of achieving the state’s climate goals, due to their ability to store solar energy effectively. However, the safety of these projects is also under public scrutiny due to concerns about fires.
Fire Marshal Jason Nailon said the guidelines will evolve and must be updated regularly to keep up with BESS technology advancements and new regulations.
“This document serves as a best-practices guide for developer guidelines,” Nailon said. “Given the evolving nature of our BESS testing and requirements, this document is continually being developed. Staff and myself are already working on updates to version two.”
San Marcos leaders last discussed this topic in September, when the council considered a resolution to oppose the Seguro BESS project planned for the unincorporated area of Eden Valley between the borders of Escondido and San Marcos. The council chose not to take a stance on Seguro then, but instead developed regulations for these projects.
The Seguro project has drawn strong opposition from residents in Eden Valley and Escondido due to its close proximity to residences and Palomar Medical Center. Last year, Escondido leaders temporarily banned new battery storage projects to allow more time to draft zoning regulations.
San Marcos Mayor Rebecca Jones said the city’s new guidelines will apply to Seguro, as it lies within the San Marcos Fire Protection District, but they are meant to guide all battery storage projects.
“This is not specific to Seguro; it’s related to every lithium ion BESS facility,” said San Marcos Mayor Rebecca Jones. “Tonight is actual policies and guidelines that are going to be a living, breathing document.”
Guidelines
The 20-page guideline document lists several requirements for proposed projects, including 100-foot setbacks from lot lines of residential, educational and institutional uses, 10 feet of distance between each storage container, emergency vehicle access roads within 150 feet of all parts of the facility, and water supplies onsite in case of fires.
Developers must also submit reports related to plume modeling, hazard mitigation, explosion control systems, emergency preparedness plans, proof of large-scale fire testing, and demonstration of compliance with applicable fire codes.
Concerns about BESS facilities have risen in recent years due to thermal runaway events, which occur when a battery’s temperature rises rapidly and uncontrollably, causing a fire. These incidents can release dangerous chemicals into the air or cause them to leak into the earth.
In September, a blaze broke out at a San Diego Gas & Electric lithium ion battery facility in Escondido, resulting in the closure of several schools and the evacuation of nearby businesses. The fire was limited to one battery container, but it still stoked residents’ worries about the impact on air quality.
In January, a large blaze burned for several days at the Moss Landing BESS facility in Northern California, causing the evacuation of over 1,200 residents. A group of residents have since filed a lawsuit against facility owner Vistra and other entities, claiming they failed to implement sufficient fire safety measures.
In San Marcos, residents said the high wildfire risk in the area makes it even more important to have guidelines in place for battery energy storage.
“I want to thank the city council and the fire department for being at the forefront of ensuring that this city has comprehensive protection guidelines for BESS facilities,” said San Elijo resident Lindsey Smith.
Phyllis Laderman, who lives on Surrey Lane directly adjacent to the proposed Seguro site, said she is grateful to see regulations but would like them to be more strict.
“I’m glad to see them, I actually personally don’t feel they go far enough, but that’s because I have a personal vested interest in all of this,” Laderman said. “I would really urge that you approve this, because it is a starting place.”
Increasing education
Despite community concern, energy leaders in the county say the technology for battery energy storage is much safer than in the past. Data from the Electric Power Research Institute indicates that BESS facility incidents are decreasing even as the number of projects grows.
At the Clean Energy Alliance’s Feb. 28 board meeting, leaders said the facilities experiencing fire incidents are “legacy” projects utilizing old technology, which have a higher chance of thermal runaway than new projects.
“The incidents that happened here in our region were legacy projects, projects that were built early on and so were designed and built under a totally different standard of codes than we have today,” said Cleantech San Diego President and CEO Jason Anderson. “You all, and the general public, I think have every right to be concerned, but I also hope we can start to be more properly informed.”
The CEA, which serves the cities of San Marcos, Carlsbad, Del Mar, Escondido, Oceanside, Solana Beach and Vista in a community choice aggregation program, has been discussing safety standards as they approve BESS projects in the county, such as an energy storage agreement for a 6-megawatt BESS project at Camp Pendleton.
San Marcos City Councilmember Maria Nuñez, who also serves on the CEA Board, said she would like to see more education and engagement with the public about battery energy storage projects.
“I share a lot of the concerns that the residents have brought forward today. What I would like to see is a lot more education. I think this is very complicated, but I also think it’s very critical for us to embrace this technology,” Nuñez said at Tuesday’s council meeting.
San Diego County is also updating regulations for BESS projects in unincorporated areas. The county Board of Supervisors adopted interim guidelines in December based on the current county fire code, and expects to adopt an updated code at the end of the year.
There were 10 battery energy storage system projects under review in the county in December.
