California regulators have proposed new safety standards for battery energy storage systems following a series of incidents at the facilities, including a major fire Jan. 16 at Vistra’s Moss Landing site. 

The California Public Utilities Commission is proposing the standards as an update to General Order 167, which likely was adopted in 2004 and sets safety standards for electric generating facilities. The commission is expected to consider the update, known as GO 167-C, during a March 13 voting meeting. 

“Regulatory oversight of ESS [energy storage system] facilities is necessary because of the safety and reliability risks that can occur if ESS facilities are not properly operated and maintained,” the CPUC said in a proposed resolution to adopt the standards. 

In addition, a bill has been introduced in the California legislature addressing battery storage system safety. Assembly Bill 303 would restore local oversight for energy storage projects in the state, according to its author, Assemblymember Dawn Addis (D). 

Under the CPUC’s proposed standards, battery energy systems would face similar requirements to those of electric generating facilities.  

For example, ESS owners would be required to file operation and maintenance plans with the CPUC, steps now required of generating asset owners. ESS owners also would be required to report safety-related incidents to the CPUC within 24 hours — just as generating asset owners must do now. 

And in a new mandate for both energy storage and electric generation, facility owners would be required to work with local authorities to develop an emergency response and emergency action plan. 

The changes are in response to direction from state lawmakers in Senate Bill 1383 of 2022 and SB 38 of 2023. 

The CPUC held three workshops in 2024 to gather feedback while developing the proposed standards. 

Battery Blazes

Battery storage is seen as key to meeting the state’s clean energy goals. Batteries can store solar energy during the day and release it during peak demand in the evening. 

California’s battery energy storage capacity increased from 770 MW in 2019 to 13,391 MW in October 2024, with about 3 GW of that added since April 2024. (See California Hits Milestones for Batteries, DR Grid Support.) 

That puts the state at about a quarter of its projected energy storage need of 52,000 MW by 2045. 

But battery storage presents safety concerns. The worries were underscored Jan. 16, when a fire broke out at Vistra’s 300-MW energy storage facility at Moss Landing in Monterey County. The lithium-ion battery facility is one of the world’s largest battery energy storage systems. 

The fire, which prompted the evacuations of 1,200 people, is under investigation. Staff from the CPUC’s Safety and Enforcement Division visited the site Jan. 22 as part of its probe. 

The CPUC listed nine other safety incidents at battery facilities since 2021, including four in 2024. In one incident in September 2024, a fire at a San Diego Gas and Electric battery storage facility in Escondido prompted evacuations. 

Evacuations also were ordered in May 2024 during a fire at REV Renewables’ Gateway Energy Storage facility in Otay Mesa. 

Battery Safety Bill

AB 303 from Assemblymember Addis is known as the Battery Energy Safety and Accountability Act. 

The bill would prohibit battery energy systems of 200 MWh or more on an environmentally sensitive site or within 3,200 feet of a “sensitive receptor,” such as a home, school or community center. 

The bill also would exclude battery storage projects from the California Energy Commission’s opt-in certification process, a streamlined path to approval. (See 2 Huge Solar-plus-storage Projects Planned in California.) 

Under the opt-in process, the CEC becomes the lead agency for permitting and state environmental review. The CEC certificate is in lieu of any permit that normally would be required through the local land-use review process and most state permits. 

“AB 303 is a proactive measure that will ensure companies like Vistra go through the normal, local, regulatory process,” Addis said in a statement. “It is designed to build trust, increase safety and give communities a choice by restoring local community processes for permitting these projects.” 

The California Energy Storage Alliance is opposed to the bill, saying it is “excessive and does nothing to enhance public safety.” 

“Instead, it creates unnecessary barriers to the deployment of critical energy storage systems needed to stabilize our grid and support California’s transition to a clean energy future,” CESA said in a release. 

AB 303 is awaiting assignment to committee.