The increases in the number and size of energy storage systems (ESS) has brought with it a growing potential for fire hazards. While numerous technologies can be used in an ESS, batteries are the most common. These systems pose a unique set of fire risks, including the possibility for unstable chemistries to start a fire or contribute to fire load. In addition, some battery chemistries produce their own oxides during combustion, and suppression agents are limited to just cooling and slowing, but not stopping, the thermal runaway.
Identifying the risks of these large energized boxes and how to deal with them has been a significant focus for the National Fire Protection Association (NFPA) and other safety and research organizations over the last several years. The vast majority of deployed ESS blend into the background, hidden inside nondescript boxes outside of office parks or subdivisions. Increasingly, however, they are tucked inside apartment buildings, in parking garages, on rooftops, in strip malls, and on worksites.
Standards bodies are trying to keep up. As part of the 2018 update of NFPA 1, Chapter 52 of the standard was renamed “Energy Storage Systems” and underwent a complete reorganization and rewrite. The rewrite was intended to recognize both established battery technologies and new technologies, and also reflect existing and new applications of these energy storage systems.
A much larger and more comprehensive project is the development of NFPA 855, Standard for the Installation of Stationary Energy Storage Systems. This standard is currently in its second draft, and the first edition could be published as soon as early 2019.
Battery room of an energy storage system
The main objective of NFPA 855 is to understand the many risk variables involved for a specific installation—ESS type, size, quantity, application, location, etc.—and then try to limit those risks. The developing standard includes guidance for a wide range of battery and chemistry types on issues such as installation, ventilation, maintenance, operation, decommissioning, and fire prevention. The draft also includes an appendix of best practices for firefighters as well as an overview of system hazards.
Presently, there are nine distinct ESS types included in the NFPA 855 draft standard, and many of those have various subcategories with different properties and unique hazards. In a few more years, there could be many more.
The relative newness of ESS, coupled with the growing number of locations and applications where the systems are used, means there is limited fire testing data for the standards committee to consult. As a result, critical safety guidance such as battery spacing, maximum allowable sizes and quantities of batteries inside a room, and even what type of suppression systems will adequately extinguish an ESS fire still remain best guesses.
With Risk Logic, Inc.’s expert knowledge of NFPA and other industry standards, we can answer your questions regarding ESS property loss prevention exposure and advise as to how it can apply to your facility.
FPA Journal, "Rapid Advance: An update from the evolving world of energy storage systems"