Policy Briefing — Updated lithium-ion ESS permitting playbook for AHJs and developers

DOE/PNNL’s 2023 ESS compliance guide and 2024 IFC Section 1206 clarifications are reshaping submittals: pre-application packages now hinge on UL 9540 listings, UL 9540A gas dispersion data, and first-responder isolation points.

Zeph Tech Research Lead

Research lead, Zeph Tech

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Executive briefing: Pacific Northwest National Laboratory’s 2023 Energy Storage System Guide for Compliance with Safety Codes and Standards and the 2024 International Fire Code (IFC) updates to Section 1206 have become the de facto checklist for lithium-ion ESS permitting in U.S. jurisdictions. Authorities having jurisdiction (AHJs) are pressing developers to submit unified documentation packages that pair UL 9540 listings, UL 9540A gas release profiles, and clear firefighter disconnect locations before plan review will commence.

Key obligations

Pre-application dossiers. Compile site plans with cabinet spacing, rooftop setbacks, ventilation exhaust locations, and single-line diagrams that match UL 9540-listed configurations.
Gas and smoke management. Where UL 9540A data show flammable gas release, the IFC 1206.7 pathway requires exhaust sized to keep concentrations below 25% LFL and detection that activates ventilation.
Emergency operations. Plans must identify remote stop stations, BMS fault annunciation, and firefighter information signs per IFC 1206.11; responders expect copies of manufacturer emergency procedures on site.
Maintenance and inspection. AHJs are requesting documented state-of-charge controls, quarterly visual inspections, and annual maintenance logs aligned to manufacturer instructions.

Implementation timeline

Immediate for new permits. Jurisdictions adopting IFC 2024 are applying Section 1206 changes now; even 2021–2022 code areas are conditioning permits on the PNNL guide’s submittal checklist.
Retrofits. Expansions that add cabinets or chemistries typically trigger updated hazard mitigation analyses and refreshed UL 9540A datasets.
Responder coordination. Many fire departments now require pre-incident plans before energization, with joint acceptance testing of disconnects and ventilation controls.

Program actions

Standardize submittals. Build a repeatable ESS permit binder: cover sheet, site plan, one-line diagram, UL 9540 listing sheets, UL 9540A extracts, ventilation calculations, and emergency procedures.
Model gas dispersion. Use UL 9540A release rates to validate exhaust sizing and detector placement; document assumptions and safety factors in the hazard mitigation analysis.
Train responders. Offer pre-incident walkthroughs showing disconnects, signage, and BMS fault indications; share OEM emergency response guides.
Embed O&M controls. Incorporate state-of-charge limits, inspection frequencies, and thermal-imaging checks into site operating procedures and computerized maintenance management systems.