Supporting Utilities in Meeting GO 167-C BESS Requirements: Case Study

AEES recently conducted an independent compliance audit of a California utility with several Battery Energy Storage System (BESS) facilities. The audit came at a critical time: The CPUC recently modified GO 167 to a new version often referred to as GO 167-C, which for the first time explicitly covers Battery Energy Storage Systems (BESS / Energy Storage Systems, ESS. reinforcing the state’s focus on safety, reliability, and reporting transparency.

Key elements introduced or emphasized:

Requirement Area	Summary of Obligation	Implications / Notes
Scope & Applicability	GO 167-C extends CPUC’s maintenance, operation, and safety oversight to BESS (ESSs) above certain capacity thresholds.	Smaller BESS may have some exemptions or reduced requirements; full obligations typically apply to larger systems (e.g. >50 MW).
Maintenance & Operation Standards	BESS must adopt maintenance and operation programs consistent with industry best practices, with documented plans, training, inspections, preventive maintenance, trend analysis, and safety protocols.	Existing BESS operators will need to revise or expand existing O&M programs to align.
Technical Logbook Requirements	Facilities must maintain logbooks (or equivalent technical record systems) of operations, maintenance, alarms, failures, etc. These records are subject to audit and retention.	Must retain for multiple years; entries must be clear, timely, and not altered.
Incident / Safety Reporting	Qualified “safety incidents” such as fires, serious injuries, thermal runaway, or major equipment failure must be reported. Some elements require immediate verbal or electronic notice, followed by written reports.	The new rules tie reporting obligations more tightly to safety events, and they explicitly frame non-reporting as a risk.
Emergency Response / Emergency Action Plans	Operators must develop, maintain, and coordinate Emergency Response Plans (ERPs) and Emergency Action Plans (EAPs, evacuation or response plans). These plans must cover premises, coordinate with local first responders/emergency agencies, and include procedures for equipment failure, communication, offsite impacts (e.g. air quality, water runoff), shelter‐in‐place or road closures.	These plans must be submitted to local jurisdictions (county, city), and potentially to CPUC.
Coordination with Local/First Responders	In developing emergency response plans, operators must coordinate with local emergency management agencies, Unified Program Agencies (UPAs), local first responders, and AHJs (Authorities Having Jurisdiction).	This ensures that the plan aligns with community emergency protocols.
Certification & Filings	Operators may need to submit verified statements or certifications showing compliance with maintenance, operation, logbook, and safety programs within an initial timeframe, and periodically thereafter.	New owners may have shorter windows; existing facilities have deadlines to certify.
Corrective Actions & Material Changes	If deficiencies are found or changes occur (e.g. design modifications, operational changes), the operator must notify CPUC and undertake corrective actions under oversight.	Operators must maintain continual compliance, not just one‐time compliance.
Audits, Inspections, Investigations & Cooperation	BESS owners must cooperate fully with CPUC’s Safety & Enforcement Division (SED) audits, inspections, data requests, investigations, and provide access to records and logs.	They may face scrutiny of documentation, system components, and response actions.
Retention & Confidentiality Provisions	Records, logs, and documentation must be retained (commonly for 5 years) and may be subject to confidentiality protections or requirements under CPUC rules.	Operators must manage access control and ensure chain of custody when data is used in an audit or enforcement.

Objectives

AEES was tasked with:

• Evaluating the effectiveness of the utility’s current processes for compliance with GO 167-C and SB 38.

• Determining readiness to meet CPUC’s expectations around incident reporting, emergency response planning, and firefighter coordination.

• Providing independent assurance to leadership that systems and practices could withstand regulatory scrutiny.

Audit Approach

AEES designed a comprehensive, multi-step audit process designed to go beyond paper reviews and add real value:

• Document Review – Examined ERPs, evacuation plans, incident reports, and logbooks. Compared policies, procedures, ERPs, training programs, and logbooks against GO 167-C, SB 38, and NFPA 855 benchmarks.

• Site Visits & Field Inspections – Observed facilities, safety equipment, and maintenance programs.

• Interviews & Walkthroughs – Spoke with operators, managers, field and compliance staff to test knowledge of new requirements.

• Testing & Sampling – Tracked reporting of past incidents and near-misses against CPUC timelines.

• Emergency Coordination Assessment – Evaluated how BESS sites worked with firefighters and emergency responders, including:

  • Joint drills and tabletop exercises.

  • Accessibility of ERPs and chemical hazard information to fire departments.

  • Communication procedures for thermal events, smoke, or shelter-in-place orders.

Value Delivered

By combining policy analysis, operational testing, and field inspections, AEES provided the utility with:

• Clarity – Clear understanding of how new GO 167-C and SB 38 requirements apply to BESS operations.

• Confidence – Independent assurance that the company’s programs were aligned with evolving CPUC oversight.

• Strategic Insight – A roadmap for staying ahead of regulatory enforcement, reducing compliance risk, and building stronger trust with regulators and local communities.

Outcome

The engagement delivered substantial value:

• The utility gained confidence that it's incident reporting, emergency response planning, and firefighter coordination were aligned with the latest requirements.

• Leadership received a clear, independent assessment of readiness for CPUC oversight and GO 167 compliance.

• The company emerged from the audit better positioned to demonstrate transparency, safety, and regulatory alignment, protecting both its operations and reputation.

Conclusion

This case study highlights how AEES delivers more than compliance checklists. Through a blend of policy expertise, site-level inspection, and collaborative engagement, we provide utilities with actionable assurance that they are prepared for California’s new BESS oversight environment.

✨ AEES continues to help utilities and energy companies prove preparedness under GO 167-C, SB 38, and NFPA 855 — ensuring that safety, compliance, and operational excellence go hand in hand.

Contact us to see how we can help you.