It would also increase Public Utilities Commission oversight of emergency response action plans for battery storage facilities, under Senate Bill 38 (SB 38). The proposal is a modification to the existing General Order 167, which governs operation and maintenance of electric generation facilities in California.
SB 38 was signed into law by California governor Gavin Newsom last October after being introduced by Senator John Laird in December 2023. While that already made it mandatory for battery storage owners and operators to put in place emergency response plans and communications protocols with first responders, the CPUC-proposed revision gives the regulator greater powers of oversight.
The CPUC is set to vote on the proposal 13 March 2025 at a meeting.
The announcement followed the fire at MOSS300, the 300MW/1,200MWh Phase 1 of Moss Landing Energy Storage Facility in California’s Monterey County, which began in the afternoon of 16 January 2025.
The fire took out almost all of MOSS300, although the second and third phases of the 750MW/3,000MWh facility and a combined cycle gas turbine (CCGT) power plant at the same site appeared to be unaffected.
It also triggered an evacuation order for between 1,200 and 1,500 local people, prompted road closures and Environmental Protection Agency (EPA) air quality monitoring for hydrogen fluoride gas levels in the surrounding area.
While thankfully no injuries or fatalities have been reported, the event was described as a “wake-up call for the industry” by Glenn Church, a Monterey County supervisor, who said in a press conference that while he accepted the need for battery storage as an enabler of sustainable energy, the systems must be safe and similar events prevented from ever occurring again.
While project owner Vistra Energy immediately said an investigation into the incident including root cause would be undertaken, local politician Dawn Addis, California Assembly member for the 30th District – which includes part of Monterey County – called for an independent investigation. This call was later echoed by governor Gavin Newsom.
The CPUC said on Monday that its Safety and Enforcement Division (SED) staff have initiated their investigation into the incident at Moss Landing, requesting information and updates and communicating with Vistra Energy. SED staff made a site visit on 22 January, the CPUC said.
California has more large-scale battery energy storage systems (BESS) in operation than any other US state, with cumulative installations exceeding 13GW of mostly 4-hour duration systems as of October last year, according to the California Energy Commission (CEC). Multiple new facilities have also come online since then.
While fire events are rare – the US Electric Power Research Institute’s (EPRI’s) BESS Failure Incident Database shows the frequency of BESS failure incidents including fires and other failures to have fallen 97% between 2018 and 2023 – California’s lawmakers and communities are keen to mitigate risks as much as possible.
New legislation would put Vistra’s Morro Bay project on hold
Addis also introduced new legislation pertaining to battery storage at the beginning of the week with a press conference held 27 January.
Addis’ Assembly Bill 303 (AB 303), the ‘Battery Energy Safety & Accountability Act,’ proposes removing rules that allow persons proposing battery energy storage facilities of 200MWh capacity or more to apply for certification with the California State Energy Resources Conservation and Development Commission, effectively bypassing the need for local authority permitting.
AB 303 would also require that BESS projects of that scale must be located at least 3,200 feet away from sensitive receptors, defined by the California Air Resources Board as children, the elderly, asthmatics and others at heightened risk of negative health outcomes from exposure to air pollution. Facilities would also be prohibited from construction in an environmentally sensitive site.
The legislation is similar in scope to another bill Addis previously introduced to prevent oil and gas operations from being placed in locations close to communities and environmentally protected regions.
Moss Landing Energy Storage Facility is itself in one of those environmentally sensitive areas, in which it was built due to the fact that, with a fossil fuel power plant having stood in the spot for decades, the site offered close access to existing grid connection infrastructure.
Meanwhile, its owner Vistra Energy recently sought to go the state permitting route for its planned 600MW/2,400MWh project in Morro Bay (Premium access), in California’s San Luis Obispo County, about 240km south of Moss Landing.
The Morro Bay project would also be built on the site previously occupied by a fossil fuel power plant, in this case a 1950s-built gas plant which closed in 2014.
Vistra proposed the BESS facility for the site in 2020, subsequently making presentations to the Morro Bay city council and producing a safety report peer-reviewed by quality assurance firm DNV that found that even “a credible worst-case scenario would not present any significant health or safety risk to the public.”
AB 303 would take the route by which a final decision on the BESS project would be in the hands of the CEC and California Coastal Commission (CCC) away from Vistra, and referring to the scene at Moss Landing, Addis said last week that there was “absolutely no way to support this [project] in Morro Bay after seeing what I’ve seen.” Morro Bay is also within the 30th California Assembly District Addis represents.
The project was dealt another blow at the local level after, according to local media reports, the Morro Bay City Council voted to block any BESS project proposals within its city limits in a meeting held 28 January. The ordinance is valid for 45 days, after which the council will vote whether to impose a further two year halt.