June 22, 2023

Improving Fire Safety in Response to Energy Storage System Hazards

At SEAC's May 2023 general meeting, IAFF's Sean DeCrane gave a presentation on mitigating energy storage system (ESS)-related fire risks.
Still image of UL Fire Safety Research Institute's lithium battery fire testing

Fire departments need data, research, and better training to deal with energy storage system (ESS) hazards. These are the key findings shared by UL’s Fire Safety Research Institute (FSRI) and presented by Sean DeCrane, International Association of Fire Fighters Director of Health and Safety Operational Services at SEAC’s May 2023 General Meeting.

In April 2019, a firefighter was thrown 75 feet through the air in an explosion at a battery facility in Surprise, Arizona. FSRI investigated the response of the fire service to the lithium-ion battery explosion. First Responder and Technical Analysis reports on the accident are available here and here.

The reports point out four main contributing factors in the response to the explosion incident and how to mitigate safety risks in future incidents: the need for better education and training for the fire service and industry representatives, detection of battery fire hazards, emergency response plans, and explosion prevention and protection.

Develop ESS Education and Training

Contributing Factor: Hazardous materials (HAZMAT) training curricula for first responder and technician levels do not cover basic ESS hazards and incident response at lithium battery systems. 

Recommendations: Training should emphasize ESS safety, the potential explosion hazard from lithium-ion batteries, vapor cloud formation and dispersion, and the dynamics of ESS combustion.

Research and full-scale testing will help understand and develop response tactics for lithium-ion battery ESS incidents.

Online education tools can proliferate the appropriate base knowledge on lithium-ion battery ESS hazards and fire service tactical considerations. FSRI has an online training module on fire service considerations with Li-ion battery ESS.

Improve Detection of Battery Fire Hazards

Contributing Factor: Remote gas monitoring can warn first responders about the presence of flammable gas. Without sensors, HAZMAT teams cannot monitor toxic gas concentrations or other conditions inside the ESS from a physically secure location.

Recommendation: Research and testing can increase the effectiveness of stationary gas monitoring systems for lithium-ion battery ESS.

Develop Emergency Response Plans

Recommendation: ESS owners and operators, in conjunction with local fire service personnel and code authorities, can develop emergency operations plans for dealing with ESS incidents, starting with signage to alert personnel on the presence of ESS.

Incorporate Explosion Prevention Protection

Recommendation: Research and testing on fire suppression and explosion prevention systems for lithium-ion battery ESS should address project sites over an extended period of time.

“As you approach your explosion mitigation or deflagration strategy or decommissioning planning, you have to think about your installation today and what your installation will look like tomorrow,” DeCrane said.

FSRI Research And Testing

FSRI conducted three tests to simulate combustion and protection systems for lithium battery fires.

  • One test took place without any provision for fire protection.
  • A second test used the Novec 1230 fire protection fluid, a product sold by the chemical company 3M but not recommended by 3M for this scale of an installation.
  • A third test used sprinklers that sprayed water from ceiling sprinkler installation at .5 gallons per minute.

The tests yielded two key findings regarding gas detection and deflagration. Deflagration refers to the rapid spread of fire through a gas.

Common combustible gas, carbon monoxide, and hydrogen detectors were effective for thermal runaway gas detection, but they were considered unreliable for ongoing hazard assessment. Battery fires produce more hydrogen, which presents a unique hazard for fire departments.

Deflagration occurred in all three tests with intensity varying based on the gas conditions at the time of ignition. The deflagrations were mitigated with an engineering deflagration protection system designed as per the NFPA 68 Standard on Explosion Protection by Deflagration Venting.

From these test findings, the FSRI developed two tactical considerations for responding to and mitigating ESS hazards.

  1. Thermal imaging is inadequate for ESS fire assessment. Thermal imaging cameras do not enable evaluation of the number or location of ESS units in thermal runaway. They also provide limited ability to determine whether a suppression system has operated or is operating. And they are not a viable tool for determining the nature of visible vapors, such as battery gas, steam, or Novec 1230.
  2. A deflagration event is hard to predict even with good-quality gas concentration data. Responding firefighters should consider using portable gas meters and visual observations to define an exclusion zone.

“One of the difficulties we have in developing solid standard operating procedures is the inconsistency of the battery failures,” DeCrane said. “We’ve seen batteries ignite early in the gas release or in some cases, the batteries might not ignite for 16 minutes after the gas release.”

More Resources

To learn more about lithium-ion battery fire safety, visit the FSRI resource library for a March 30 symposium in Alexandria, Virginia. The resource library features several presentations, including DeCrane’s presentation on energy storage testing and firefighter safety, a panel discussion on lithium battery challenges for the fire services—also featuring DeCrane—and much more.

In addition, you can join a SEAC working group, including the Storage Fire Detection working group and the ESS Standards working group, that’s working to improve fire safety with ESS.

Lastly, join SEAC for a virtual workshop on safety and risk considerations when permitting ESS. The workshop, taking place Wednesday, Aug. 16 from 12 p.m. to 4 p.m. EDT, is designed for building departments, fire departments, installers, and manufacturers. Workshop leaders will review the technology, safety standards, tests, codes, common issues with permit applications, and plan review. There will be ample time for a question-and-answer session.