Recently, eight Arizona firefighters were injured – three seriously and one critically – when an explosion occurred while they were inspecting a “utility size” lithium battery.
Both the Peoria (Arizona) Fire-Medical Department and the Surprise Fire Department had responded to a report of smoke coming from the APS McMicken Energy Storage facility in Peoria. The explosion apparently occurred as the Peoria Hazmat Team began to enter the building. The explosion knocked the critically injured firefighter unconscious and required three of the firefighters to be airlifted to a burn unit in Phoenix, while the others were transported to a local hospital.
This incident points to the potential hazards of both energy storage systems and the dangers associated with lithium storage batteries.
Thermal runaway phenomenon in lithium batteries
Over the past few years, I have written extensively about the hazards of lithium ion batteries. These articles started after the Indianapolis Fire Department responded to a fatal motor vehicle crash and fire that involved a Tesla automobile, and reported how difficult it was to completely extinguish the resulting fire. IFD made several recommendations about how such fires could be handled based on their experience.
The phenomenon known as a “thermal runaway” occurs when poorly made or poorly shielded lithium batteries catch fire from a chemical reaction inside the battery cell. This causes an increase in temperature, eventually spreading from cell to cell and, in some cases, causes serious burns to people and devastating fires. This chemical reaction can also occur when an external fire sufficiently heats the battery to start the thermal runaway reaction.
Several departments have experienced residential fires that began in such items as hover boards, toys and vape pipes. Many airlines advise you not to bring anything with lithium batteries on your person, in carry-on or in your checked bags for fear of a thermal runaway occurrence.
I’ve also explored energy storage systems (ESS), currently used in commercial settings, which are being proposed for residential use as part of a move toward greener energy sources. These ESS utilize lithium batteries for storage because of their increased capacity to hold energy over more conventional battery systems. This most recent incident highlights the dangers associated with lithium batteries in an ESS setting.
It is essential that we in the fire service keep up with the ongoing investigation at the APS McMicken Energy Storage facility, take into consideration the recommendations that will be made, and make sure that we are aware of and preplan both residential and commercial ESS facilities in our response area.
Stay safe.
