California Battery Blaze
Another fire sprang up just last week, when a Tesla Megapack operated by Pacific Gas & Electric was reported as burning on September 20th.
The safety systems built into the big Tesla battery stopped the fire from spreading - or even causing disruptions in the power grid - and PG&E reported no injuries to on-site personnel.
The energy company has run their Elkhorn Battery Storage Facility in Monterey County, California since April. It’s made up of 256 Tesla Megapack units on 33 concrete slabs and has a 730 MWh capacity.
There’s no word yet on what exactly caused the fire in the first place, but California has suffered intense heat waves lately, so it’s not impossible one of the battery pods contained in the Megapack overheated.
In fact, one of the reasons the safety systems worked so well is because Tesla has already thought of the overheating issue. Batteries are filled with volatile chemicals - that’s how they store energy. And while Megapacks have cooling systems built in, it’s inevitable that there will be some fires - like the one in Australia last July.
So way back in 2016, Tesla decided to see what would happen if one of their Powerpacks - the predecessor to the Megapack - caught fire. While the design has changed a bit since the Powerpack, Megapacks use a similar system of energy storage pods - each filled with battery cells. The pods serve to isolate individual groups of batteries from each other, and - as testing of the Powerpack showed - serve to contain fire to as few pods as possible.
In addition to the safe construction, Tesla’s Megapacks have automatic cutoffs that isolate a unit from the grid if a fire is detected. All of this came together to protect the rest of the Elkhorn facility last week.
The general consensus of the industry seems to be that with the amount of Tesla Megapacks coming online, it’s inevitable that there will be some fires. Conventional power systems catch fire under similar stresses - heat, storms, heavy wind, that sort of thing - so there doesn’t seem to be much cause for alarm in this case. Especially since the safety mechanisms worked flawlessly.