The first incident involving a Tesla Semi occurred in the Greater Sacramento area in northern California yesterday. The highway in Placer County was closed by the responding California Highway Patrol unit.
Semi Fire
The exact causes and details of the fire and incident remain unclear at this time, but it seems that the Semi caught fire around 3 AM immediately following the crash. The highway was closed in both directions due to the fire and remained closed until late afternoon for the westbound lanes, while eastbound was closed until about 7:30 PM. The incident began as a crash, and no injuries were reported.
Batteries
Electric vehicle fires are rare, in fact, they’re much rarer than traditional vehicle fires, but there are a few key facts to keep in mind. EV fires tend to be devastating for several reasons – the materials in the battery can be toxic when exposed to the air – especially through the smoke and fumes of a fire. In addition, due to the massive amounts of energy that EV batteries can store, EV fires can blaze for a long period of time. We recently dug into EV battery electrolytes and the chemistry in batteries.
This Tesla Semi fire is particularly devasting, partly due to the Semi having a ~900kWh battery – nearly 9-10 times that of a Model Y. In a recent incident report involving a Model Y fire, it took about 10,000 gallons of water and 4 hours to extinguish the fire. This one began burning at 3 AM and it wasn’t until more than 12 hours later that the battery temperature was under control.
On the flip side, EV fires tend to happen far less often than ICE fires – with an EV fire being 8x less likely than an ICE fire, according to Tesla’s Impact Report. When they do happen though, first responders need to be well trained with how to deal with EV fires.
Firefighter Response
First responders on the scene have had to don HAZMAT suits in order to respond to the fire, and the fumes from the fire are the primary reason that the local roadway has been closed. In general, the immediate response for EV fires is to cool the battery pack, generally using water. Other options include submerging the pack in water to immediately cool it, or to bury the pack with sand, or just letting it burn itself out.
For now, first responders appear to be hosing down the Semi with just water, and nothing else is on the books just yet. The Semi is on fire pretty close to a major treeline, but luckily California hasn’t had a spate of dry weather recently, so the risk of this evolving into a major wildfire remains pretty low, according to officials.
