NFPA 855: 2026 Edition Updates and What They Mean for Energy Storage Projects

Why It Matters

Project teams must adapt to stricter safety and documentation demands, or risk delayed approvals and higher insurance costs. The updates also signal a maturing market where regulators expect performance‑based evidence of fire resilience.

Key Takeaways

• HMA now required for most ESS installations
• New chemistries like iron‑air and zinc‑air explicitly covered
• Large‑scale fire testing (LSFT) added alongside UL9540A
• Emergency response plans must be reviewed annually with AHJ
• Registered fire‑protection engineer must lead risk‑assessment design

Pulse Analysis

NFPA 855 has quickly become the benchmark for safely deploying battery storage across the United States, and the 2026 revision reflects a decade of field experience and emerging technologies. By expanding the scope to include hybrid supercapacitors, iron‑air, sodium‑sulfur and other advanced chemistries, the code reduces ambiguity for developers working with next‑generation systems. This clarity helps utilities and commercial owners justify capital expenditures, as they can now reference a single, authoritative standard rather than piecing together multiple legacy codes.

One of the most consequential shifts is the elevation of Hazard Mitigation Analysis (HMA) to a default expectation. Previously, HMA was only triggered when projects exceeded prescriptive energy limits; now, unless a specific exemption applies, designers must conduct a performance‑based risk assessment. Coupled with the new requirement for large‑scale fire testing (LSFT) that complements UL9540A, stakeholders gain concrete data on thermal‑runaway propagation, reducing reliance on theoretical models. While these measures improve safety, they also introduce additional engineering effort, testing costs, and longer schedule timelines.

For developers, the updated emergency response plan (ERP) mandates annual reviews and coordinated training with the AHJ, reinforcing a proactive safety culture. The emphasis on a qualified fire‑protection engineer to steer the risk‑assessment process ensures consistent interpretation across jurisdictions. Looking ahead, the forthcoming NFPA 800 battery safety code will likely build on these foundations, further integrating lifecycle considerations. Early engagement with fire‑protection experts and clear documentation will be essential to navigate the evolving regulatory landscape and keep projects on track.