GO 167-C: What California BESS Owners Must Do Now (and the Risks if You Don’t)

California just overhauled its power-plant safety regime and, for the first time, pulled grid-scale battery energy storage systems (BESS) fully into it. On March 13, 2025 the CPUC adopted General Order 167-C (GO 167-C) via Resolution ESRB-13, extending the state’s maintenance, operations, logbook, and emergency-planning rules to BESS and updating enforcement tools.

1. BESS Are Now Explicitly Covered

For the first time, GO-167C formally adds energy storage systems to the CPUC’s regulatory scope.

• Facilities ≥50 MW must comply with all Maintenance, Operation, and Logbook Standards.

• Systems 5–<50 MW must still demonstrate safe and reliable operation under “general duty” requirements.

  
  

This closes a major gap: before GO-167C, BESS safety practices were largely unregulated beyond local fire codes or site-specific permits.\

⚠️ Risk: Non-compliance could lead to CPUC enforcement actions or public-safety findings, especially after high-profile battery fires at Moss Landing and similar sites.

2. New Emergency Response & Action Plan Requirements

GO-167C introduces a mandatory Emergency Response Plan (ERP) and Emergency Action Plan (EAP) framework for all covered BESS facilities.

• Plans must be shared with local fire, emergency, and hazardous-materials authorities.

• Must align with Senate Bill 38 and SB 1383 requirements for fire safety and toxic-gas mitigation.

• Operators must train personnel annually on emergency and abnormal operating scenarios.

  
  

⚠️ Risk: Facilities without properly filed or coordinated ERPs/EAPs may be cited for safety violations and could face shutdowns during audits or incidents.

3. Annual Operating & Maintenance Plan Summaries

Owners of covered facilities must now file Maintenance and Operation Plan Summaries with the CPUC for the first time:

• Maintenance Plan & Logbook Certification due February 2025.

• Operation Plan & Certification due February 2026.

• Updated biennially thereafter.

These summaries demonstrate that owners have structured procedures, preventive maintenance programs, and training in place to ensure safe and reliable operation.

⚠️ Risk: Failure to submit these summaries on time—or submitting incomplete or unverified plans—can trigger citations and increase the likelihood of CPUC audits.

4. ESS-Specific Maintenance Standards

GO-167C defines new Maintenance Standards tailored to energy storage technology:

• Inclusion of battery-specific preventive maintenance, cooling-system monitoring, and fire-suppression readiness.

• New requirements for software and firmware updates, OEM alignment, and corrosion-control programs.

• Mandated documentation of maintenance activities and spare-parts management.

  
  

⚠️ Risk: Outdated or incomplete maintenance records can now be treated as violations, even if the equipment performs normally.

5. ESS-Specific Operation Standards

For the first time, CPUC sets Operation Standards (OS 1–28) that address the unique characteristics of BESS:

• Detailed procedures for charging/discharging, alarm response, and abnormal conditions.

• Requirements for software backup, cybersecurity, and control-system integrity.

• Defined expectations for CAISO coordination during grid emergencies.

• Mandatory five-year record retention for operational data and logbooks.

  
  

⚠️ Risk: Missing or poorly maintained procedures, especially around alarm response or abnormal operation, could expose facilities to CPUC findings or increased insurance scrutiny.

6. CPUC Audit and Inspection Authority Expanded

GO-167C enhances the CPUC’s authority to:

• Conduct unannounced audits, site inspections, and incident investigations.

• Enforce compliance through citations, fines, or operational restrictions.

• Require corrective-action plans and follow-up verification.

  
  

⚠️ Risk: The CPUC now has clear enforcement mechanisms for BESS safety failures—owners can no longer rely on “gray areas” that once existed for non-generation assets.

How AEES Helps BESS Owners Stay Ahead

Applied Energy & Environmental Solutions (AEES) works with California energy operators to build complete GO-167C compliance programs from the ground up.

Our approach includes:

• GO-167C Gap Assessment — Identifying missing policies, training, and records.

• Plan Development — Supporting development and formatting Maintenance, Operation, ERP, and EAP documents to CPUC specifications.

• Audit Readiness — Conducting mock audits and building evidence libraries mapped to OS/MS standards.

  
  

With AEES, your compliance doesn’t just check boxes—it protects your people, your assets, and your uptime.

The Bottom Line

GO-167C changes the game. It transforms BESS operations from a lightly regulated sector into one governed by rigorous safety and reporting obligations. For owners, the risk of non-compliance is no longer hypothetical—it’s enforceable.

Now is the time to review your facility’s procedures, emergency plans, and documentation. AEES can help you meet every new requirement and ensure your operations remain safe, reliable, and audit-ready.