Major Overhaul of Standards and Increased Oversight for Electric Battery Storage in California

On March 13, 2025, the California Public Utilities Commission (CPUC) voted to approve a resolution (titled ESRB-13) (Resolution) proposing updates to the standards for the maintenance and operation of electric generating assets and explicitly applying those standards to battery energy storage systems (ESS). Because the Electric Safety and Reliability Branch (ESRB) of the CPUC put forward the changes as a Resolution and not a formal rulemaking, the changes did not need to go through typical formal rulemaking procedures. The CPUC did solicit industry and stakeholder engagement last year when drafting the changes.

The Resolution modifies General Order (GO) 167 (Order), which establishes the electric generating facility standards for safe and reliable service as well as methods of enforcement, audits, inspections, and incident investigations in California. While there have been some minor updates since the Order’s adoption in 2004, this Resolution is the first comprehensive revision. The changes follow major advances in technology and developments in industry practices over the past 20 years, during which time California witnessed the rapid expansion of renewable generating assets and energy storage facilities, as well as safety incidents at ESS facilities since 2021. Most recently, a lithium-ion battery fire occurred at Moss Landing Energy Storage Facility in January 2025.

Under the existing Order, ESS owners were not required to report safety incidents such as injuries, fatalities, thermal runaways, fires, or other system failures to the CPUC, nor were ESS facilities subject to the Order’s maintenance and operation standards. The Resolution updates generating asset operation and maintenance standards and applies those standards to ESS facilities, as required under Senate Bill (SB) 1383, increases oversight of emergency response action plans for battery storage facilities, as required under SB 38, and increases reporting requirements, as described more fully below.

What Are the Changes to the Order?

1. Required ESS Compliance. The existing Order applies to all generating asset (GA) owners unless specifically exempt. GA means “any device owned by an electrical corporation or located in []California used for the generation of electric energy.” Under the changes, the Resolution would apply GA standards (and exceptions) to all owners of ESS, newly defined as “commercially available technology that is capable of absorbing energy, storing it for a period of time, and thereafter dispatching the energy.” 
   
   
2. Maintenance, Operation, and Logbook Standards. The Resolution updates the maintenance, operation, and logbook standards for GAs and applies these standards to ESSs to ensure compliance with modern industry technology and practices. 
   
   GA and ESS owners will be required to verify their logbooks and certify they have adopted and implemented maintenance and operation plans to CPUC. Owners will need to submit a verified statement and initial certification within 180 days of the GO’s effective date, or 90 days after the effective date of title or transfer for new owners, along with periodic updates.  
   
   
3. Emergency Response and Emergency Action Plans. GA and ESS owners will be required to prepare and submit Emergency Response and Emergency Action Plans in coordination with local authorities.
   
   
4. Safety-Related Incident Reporting. ESS and GA owners will be required to report safety-related incidents involving ESSs to the CPUC within 24 hours of occurrence. Owners will required to submit a written report of the incident within five business days. 
   
   
5. Notice of Material Change. GA and ESS owners will be required to notify CPUC of any previously unreported deficiency or material change within 30 days of the known occurrence of the material change, including any significant changes in the operation or maintenance of the GA or ESS.
   
   
6. California Independent System Operator (CAISO) Outage Coordination Protocol. ESS owners will be required to report outages to CAISO.
   
   
7. Information Requests. ESS owners will be required to respond to ESRB information requests and directives, including submitting outage reports under the ESRB Power Plant Outage Reporting requirements, releasing specified data as applicable, and responding to ESRB data requests.

Looking Ahead

Now that CPUC has adopted the Resolution with the proposed changes, stakeholders will need to begin reviewing their current maintenance and operational procedures and preparing for the new reporting requirements to meet the 180-day compliance and other reporting deadlines.