Underwriters Laboratories released a new report on a 2019 Lithium-ion battery energy storage system explosion that occurred in a deflagration event at an APS storage facility in Surprise, Arizona. In response, it is recommending new safety standards for energy storage systems [ESS].
The technical report, which was released on July 29, details the incident in which a 2.16 lithium ion battery fire injured four firefighters responding to the scene.
According to the report, on April 19, 2019, firefighters responded to a alarm indicating an issue with the energy storage system. Firefighters determined a hot zone with the help of thermal cameras, where they noted “dangerously high” levels of hydrogen cyanide and carbon monoxide.
After monitoring the concentration of the gas levels, the firefighters entered the ESS, where a cascading thermal runway led to a deflagration event, seriously injuring and hospitalizing the responders, the report said.
The report found several contributing factors to the incident, including:
- The ESS communication system failed, so responders were unable to assess conditions inside
- The fire and smoke detection systems did not include, and were not required to include, sensors that provided information about the presence of flammable gases
- The ESS’ design did not include deflagration venting per National Fire Protection Association guidelines
- The flooding clean agent suppressed flames, but was not designed for explosion protection
UL said in response to the study’s findings, it is recommending new standards and codes for energy storage systems
“Recommendations include HAZMAT training with an emphasis on ESS safety, remotely accessible gas monitoring systems, explosion prevention protection, and full-scale testing research to understand the most effective and safest tactics for fire service response to lithium-ion battery ESS incidents,” UL said in the announcement.
UL said that the investigative report, funded in part by the Department of Homeland Security [DHS] is the first of its kind as it , and is imperative to the future of battery safety.
“The ability to study lithium-ion battery-related fires on this scale with first-person accounts from the responding firefighters is critically important to protecting the lives of first responders in similar situations,” said UL FSRI Vice President of Research Steve Kerber in a statement.
“We’re dealing with new technology, which brings about new fire-related hazards. We have an opportunity to learn from this incident and improve future outcomes by sharing resources and enhancing training and safety protocols.”
This report is unique in that it takes the surviving firefighters, the four of whom were career firemen with special Hazardous Material [HAZMAT] training, into account.
“Typically, these kinds of events are examined when a fatality occurs,” Mr. Kerber said in the release. “But with this report, we’re trying to make sure the firefighter experiences are taken into account, providing valuable context to the findings so that they can be channeled into actionable insights for other fire service personnel to prevent future close calls and potential fatalities We’re incredibly grateful for Peoria and Surprise Fire-Medical teams and Arizona Public Service for providing information to support learning from this incident.”