New reports check out 2019 Arizona battery explosion

Jul 31, 2020 12:49 PM ET
  • A series of failures caused thermal runaway and a surge at Arizona Public Service Electric's McMicken battery center, according to 2 new reports that look at just how to avoid similar calamities in the future.
New reports check out 2019 Arizona battery explosion
Image: Business Wire

New details have actually arised bordering the Arizona Public Service Electric (APS) battery failing and equivalent explosion that hospitalized eight firefighters as well as one policeman in Surprise, Arizona, in April 2019.

2 just recently published reports-- one by APS, and the various other by the Underwriters Laboratory Firefighter Safety Research Institute-- expose brand-new information concerning the case

" The suspected fire was actually a substantial cascading thermal runaway occasion, launched by an inner cell failing within one battery cell in the BESS: cell pair 7, module 2, shelf 15," DNV GL Energy Insights stated in the APS report. The cascading thermal runaway was most likely brought on by an inner cell defect-- particularly, uncommon lithium metal deposition and also dendritic growth within the cell.

While the system's clean agent fire suppression system started operating to include the occasion, the system is created to snuff out developing fires in average combustibles, providing it totally inadequate versus cascading thermal runaway. From there, the event spread out with every cell and also component in shelf 15 of the system, via warm transfer, as it did not have sufficient thermal barrier defenses between battery cells. Such thermal barriers might have significantly protected against the spread.

Large thermal runaway generated a huge amount of gases, which created a flammable atmosphere within the system. Three hrs after the event began, firemans opened up the system's door, flustering the gases and also enabling them to make contact with a heat source or spark that set off the explosion.

In other words, the two reports identified 5 origin of the surge:

  1. Inner failure in a battery cell initiated thermal runaway
  2. The fire suppression system was incapable of quiting thermal runaway
  3. Lack of thermal barriers in between cells brought about cascading thermal runaway
  4. Combustible off-gases concentrated without a way to ventilate
  5. The emergency situation action strategy did not have snuffing out, ventilation, as well as entry treatments

According to APS, existing battery storage space system security requirements as well as treatments only acknowledge plunging thermal runaway as a threat. These standards do little to restrict thermal runaway, as well as fail entirely to attend to the risk of non-flaming warm transfer to neighboring cells, modules as well as racking. According to the energy, those exact same requirements focus on the means to handle a fire, yet offer no options to limit or slow cell-to-cell and module-to-module thermal runaway.

The Firefighter Safety Research Institute report involved the exact same conclusions regarding what led to the event, but it also outlines actions that can be absorbed order to alleviate the possibility of a comparable failing in the future.

  • Basic Firefighter, Officer, and also HAZMAT training ought to stress ESS safety and security
  • Research study as well as major testing ought to be conducted to comprehend one of the most reliable and also best methods for reaction to lithium-ion battery occurrences
  • Fire service personnel should define a conventional possible blast span as well as continue to be outside of it while dealing with the occasion, till conclusive methods and support can be established
  • Lithium-ion battery systems must integrate gas surveillance that can be accessed remotely
  • Additional plans for increased surveillance, security standard development and also communication between the battery system, drivers and initial -responders

While these standards will certainly take some time to establish, there is a pressing need for them faster as opposed to later on. APS has plans to mount a minimum of 850 MW of almost the same batteries throughout Arizona in the near future. And Also the United States is currently on course install as long as 2,500 MW of battery storage by 2023, according to data from the U.S. Department of Energy's Energy Information Administration.