Energy Storage System (ESS) technologies are constantly evolving, and it is expected that the codes and standards governing these systems will continue to change as regulations work to keep pace with technological advancements. The 2026 edition of NFPA 855, Standard for the Installation of Stationary Energy Storage Systems, continues the reorganization effort that started with the 2023 edition along with the introduction of several new sections, and section updates to best address safety concerns.
First, the standard expands the list of ESS technologies that are covered under NFPA 855 in Chapter 1, adding battery types such as Zinc-based, Iron-air/aqueous, Sodium-ion, and Nickel-hydrogen, as well as different types of capacitors. Alongside restructuring the standard, the new edition also expands on both Chapter 4, General, and Chapter 9, Electrochemical Energy Storage Systems, to help provide further guidance on the installation and design of ESS, with an emphasis on electrochemical systems.
Key Changes Affecting ESS Design and Installation
Some high-level changes to the 2026 NFPA 855 that are expected to impact the design and installation of battery ESS include:
- A requirement for all indoor and outdoor ESS installations of the standard, to be provided with a Hazard Mitigation Analysis (HMA).
- An expansion of the requirements for Emergency Planning and Training. Separate documents are now required for first responders in the form of an Emergency Response Plan (ERP) and for ESS personnel in the form of an Emergency Operations Plan (EOP) to provide the most suitable information for each audience.
- Requirements for the ESS Owner/Operator to provide fire department training beyond the initial training before the ESS arrives on site, to now include fire department training on an annual basis.
- In addition to the UL 9540A testing, the 2026 edition now requires a large-scale fire test in which vented gas must be ignited so that the explosion and fire propagation hazards associated with each design can be adequately evaluated.
- ESS-based electrochemical technologies prone to thermal runaway must be equipped with Thermal Runaway Propagation Prevention (TRPP) Protection Systems. The new section provides requirements beyond being listed for UL 9540, such that TRPP systems need to meet additional system and testing requirements.
- ESSs for which an explosion hazard has been identified during normal operation or a thermal event now require a more detailed deflagration analysis with regards to partial volume deflagration and system design. Additionally, these ESS must also be provided with a Combustible Concentration Reduction System (CCRS) in accordance with NFPA 69.
Early Coordination & How Code Red Consultants Can Help
As is the case with any rapidly evolving technology, early coordination is an important component of successful ESS projects. Collaboration with local AHJs supports compliance and approvals while also helping first responders understand the unique hazards associated with ESS installations and prepare for potential emergency events.
Code Red Consultants partners with owners, developers, designers, utilities, and AHJs to navigate the evolving requirements associated with energy storage systems. Our team helps evaluate code and fire protection requirements, identify compliance challenges early, and support practical solutions that align with project goals, safety objectives, and regulatory expectations. Through technical expertise, responsive support, and experience across a wide range of ESS technologies and jurisdictions, we help project teams manage risk and move projects forward confidently from planning through implementation.