Utility Battery Fire in Arizona

[Sparweb]

Good article about this 2019 accident near Phoenix AZ in the IEEE Spectrum:

Dispute Erupts Over What Sparked an Explosive Li-ion Energy Storage Accident

The firefighters were severely injured by the explosion. The building was filled with explosive gas (hydrogen/HCN?) at the time thefirefighters opened the door, exposing the building's contaminated atmosphere to fresh oxygen, causing a deflagration.

As thermal runaway moved through the rack, flammable gases continued to concentrate. Fire suppression devices were ineffective on the event.

My suspicion is that there was an emergency management plan, but that it predicted the fire suppression system to be effective. Since it wasn't, a large number of Lithium cells released gases, which were contained within the building. This left the firefighters with incorrect assumptions about what would happen the moment they opened the door.

Four Firefighters Injured In Lithium-Ion Battery Energy Storage System Explosion - Arizona

The design of the ESS did not include deflagration venting...
The total flooding clean agent suppression system prevented flaming during the early phase of the incident, but was not designed for and did not provide explosion protection.

So the explosive gases were contained by the building. The flood of CO2 or HFC probably suppressed flames at first, but once the air in the building was consumed, the HCN gas continued to build.

http://www.sparweb.ca

 

[FacEngrPE]

NFPA is currently researching firefighting considerations with ESS, here is the report.
"Hazard Assessment of Lithium Ion Battery Energy Storage Systems"

https://www.nfpa.org/News-and-Resea...of-Lithium-Ion-Battery-Energy-Storage-Systems

the report indicates that firefighting methods to be used with ESS fires are still being developed.

I wounder if flooding the container with a tanker load of liquid carbon dioxide would be effective. If the battery space could be kept inert-ed long enough to cool off, no one would need to be tempted to make an entry into the hazardous burning battery room. The only permanent fitting needed is a pipe nipple. In most locations in the eastern US liquid carbon dioxide in tanker truck quantities can be delivered from sites less than 4 hours travel time (similar to entry prep time foe some of the described events). This method has been effective in fighting shipboard fires where the fire team deemed the vessel unsafe to enter.

U.S. Fire Administration/Technical Report Series
Major Ship Fire Extinguished by CO 2
Seattle, Washington
USFA-TR-058/September 1991

https://www.usfa.fema.gov/downloads/pdf/publications/tr-058.pdf

Entering a container filled with several megawatts of burning batteries seems entirely too risky and in the above case was just tragic.

Fred

 

[byrdj]

I'll weight in even though I have no knowledge . . .

given the batteries are producing gases, an isolated vent stack with monitoring along with sufficient co2 to maintain a purge (blankets may layer)

makes me contemplate all the possible damages associated with power production

 

[Alistair_Heaton]

I have a 6.4 kWh battery sitting in my cellar.

Its a LiPOfE BYD H box.



The only thing you can do with these battery fires is cool them. Even venting all the O2 won't stop the reaction. There are now battery fire bags on commercial aircraft and the basic principle is to use expanding compressed gas to freeze the mobile phone/tablet from the videos I have seen it works quite well. After you have frozen it you wrap it up in the rest of the bag which then can contain everything if it explodes.

 

[itsmoked]

LOL Alistair, I have have 51kWh of those same batteries stacked in my living room.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Alistair_Heaton]

Wow impressive, not so small bomb comes to mind.

My places base load will take it down to 40% over night without the heating on. I have actually been surprised how much power I have pulled out of them over the last year. Its basically halved my pay off time for it.

To be honest as mine weight is in the region of 120kg... I would be worried about your floor giving way.

 

[itsmoked]

NO kidding! They're' gut-busters to move. Recognizing the weight issue they're stacked on the concrete hearth of my late fireplace. My fire place is now just an insulated recess 2mW x 0.6mD x 1.2mH. I was going to put my "house battery bank" in the recess but in a nod to the potential fire hazard I've decided to put them outside in an eventual shed. Hence they sit there taunting me and I have yet another chore (building a shed).

Keith Cress
kcress -

http://www.flaminsystems.com

 

[FacEngrPE]

As byrdj points out inerting the space does nothing to the runaway batteries. It might keep plastic and other combustibles from adding to the fire load. Inerting the battery room should discourage firefighters from entering until the space is cooled and ventilated.

 

[Alistair_Heaton]

they really don't like sub 10 deg C its your battery....

I live in an ex soviet country there is sod all chance of anyone entering anything. but then again i can run 1000V dc line strings and no disconnect bollocks, or roof nonsense. So i can put 15KWp on the roof for 1000v so thats fine by me with a 8.5 string inverter running 2 strings

 

[Comcokid]

On aircraft now the lithium batteries have a vent with rupture disc to outside the aircraft. Failure results in hot/flammable/toxic gases vented outside the aircraft. I think it would be prudent that any large installation of Lithium Cobalt have venting to the atmosphere. There are much, much safer chemistries like Lithium-Iron-Phosphate. There is no reason for a ground based battery bank where weight is of little concern to go for the highest energy-density chemistry that is also quite spectacular when it fails.

 

[Sparweb]

The LiPo's usually need venting overboard, too. Basically due to the burden of proof required to "prove they're better" which isn't always available at the 10^-X level required.

And... large batteries of any chemistry do not belong in living spaces. My VRLA battery shed:

http://www.sparweb.ca

 

[stevenal]

Wouldn’t venting nullify the clean agent fire suppression?

 

[Eufalconimorph]

Battery fires are electrical fires and chemical fires at the same time. The stored energy provides the heat, the battery itself provides the fuel and oxidizer. You don't ever want them in a small airtight volume, since then you've got a high chance of detonation instead of deflagration. And you're not going to stop the reaction except by cooling it, and even then it can restart when the temperature rises again. Fire suppression is mostly to keep the things around the battery from continuing to burn. Ideally you move the battery to a safe place while it's cold and let it burn off.

 

[Alistair_Heaton]

Saw someone in a solar group using an old chest freezer as their Battery box with a dc heater in it with smart switch to regulate it.

My first thought was I wonder if he smokes.......