ESS SIDEBAR
How much protection is enough?
Hard to say, since the results of fire testing of energy storage systems aren’t widely shared. But efforts are underway to remedy this.
BY JESSE ROMAN
For years, battery manufacturers have been diligent in testing their own products to see how they perform in fire situations and what hazards they present, according to Jim Biggins, chair of the NFPA 855 technical committee. But most of that information is considered proprietary and is siloed away, which makes it difficult for the committee to draft adequate guidance, he said.
“That was a huge problem when we were writing NFPA 855, because not all lithium-ion batteries are created the same,” Biggins said. “There are different chemical compositions, they have different characteristics, and they’re going to perform much differently [during fires]…there’s no one-size-fits-all for protection guidance.”
Biggins referred to research conducted recently by the Fire Protection Research Foundation (FPRF) and FM Global that demonstrated that two similar lithium-ion batteries can give off very different amounts of energy during fire tests. On top of that, even the way the batteries are configured in a rack—whether they’re stacked vertically or horizontally—can have a significant impact on a fire, the spread of thermal runaway, and the level of protection required.
Because of these challenges, NFPA 855 contains few specific protection requirements. Instead, the standard “pushes hard for individual system fire testing, so these companies will know more about their technology, more about what gases come off during thermal runaway, more about what protection will work with their specific chemistries and battery configurations,” said Brian O’Connor, who was the NFPA 855 staff liaison when the standard was developed. The problem with this approach is that the majority of battery testing now being done is for specific installations, and results are rarely shared in the interest of furthering safety for everyone.
But there are indications that could be changing. This summer, the FPRF sent out invitations to various stakeholders to join what it calls the Energy Storage Research Consortium. The idea is to bring together researchers, manufacturers, and a host of others to perform tests and share data and results that can be publicly disseminated so that standards like NFPA 855 can have a better foundation on which to build their safety recommendations.
“If that happens, the NFPA 855 committee can be a little more specific in some of the protection requirements than we are right now,” Biggins said. “If you look at what was done with, say, warehousing storage, you’re able to make assumptions based upon the storage classifications about how much sprinkler density you’re going to need to protect it. The idea is that hopefully we can classify the batteries in the same sort of way in different groupings for protection. Hopefully the research can get to that point. I think we will get there.”
JESSE ROMAN is senior editor at NFPA Journal. Email him feedback or story ideas at jroman@nfpa.org. Top photograph: Courtesy of the UL Fire Safety Research Institute