Likelihood is, by now, you’ve got seen footage of an EV on fireplace. It is a reasonably scary sight. Evil, black smoke rolling out from beneath the automobile, probably lit up by capturing sparks and ceaseless flames that seemingly no quantity of water can extinguish. These fires are so usually highlighted on the information and social media that it is simple to assume they’re occurring on a regular basis.
A high-profile Chevy Bolt recall associated to doable fireplace threat definitely hasn’t helped that public notion, offering ever extra ammunition to anti-EV pundits who’d have you ever imagine that parking an electrical automobile in your storage is pretty much as good as enjoying with matches in a wooden shed.
But when that have been the reality, would not we be seeing a heck of much more fires? People purchased greater than a half-million EVs within the first half of this yr alone. What’s the true fact concerning the fireplace threat of EVs? That is what we’re right here to search out out in our newest installment of EV Myths, Discharged.
What causes EV fires?
Everybody is aware of what it takes to set gasoline on fireplace: A tiny little spark will do. Gasoline’s flamable nature makes it ideally fitted to inside combustion, but it surely’s very blissful for some exterior combustion, given half an opportunity.
Battery fires, nevertheless, are a bit of extra nuanced. Your typical chemical cell in an EV is stuffed with unique elements that you could be be much less aware of, however the identical mixture of supplies that creates a remarkably energy-dense supply of energy in your automobile can even create the right storm for a very ugly fireplace.
YouTube
A gaggle of Teslas broken in a fireplace in Germany.
To get all the small print, I extremely advocate you try “The Science of Hearth and Explosion Hazards from Lithium-Ion Batteries” by Adam Barowy, analysis engineer at UL’s Hearth Security Analysis Institute. It goes into far more element than I probably may right here.
However the gist of it’s that lithium-ion battery fires sometimes occur on account of one thing referred to as thermal runaway. That is when a battery cell begins to achieve temperature quicker than it might shed it. This will occur for a wide range of causes, together with a flaw within the battery development, or a failure throughout charging.
It may also be brought on by bodily harm to the cell, which could occur in a catastrophic crash or when you occur to drive over particles that in some way manages to pierce the cell. This will trigger a brief within the battery, leading to a really fast launch of lots of vitality.
Because the cell overheats and the vitality is launched, the interior elements inside the battery start to interrupt down, together with the flammable electrolyte. It kicks off a form of incendiary chain response that won’t cease till the complete battery is consumed. These fires can burn for hours, even re-igniting after they have been extinguished.
Fortunately, there’s lots of tech in fashionable batteries to stop that from occurring, together with superior thermal administration and large quantities of crash safety, just like the carbon-fiber underbody safety within the electrical Mercedes-Benz G-Class, or the aluminum extrusions and forged elements that Audi stacks across the cells in the Audi Q8 E-Tron.
Saltwater EV fires
Within the wake of hurricane Helene, a video of a Tesla Mannequin X catching fireplace has been making the rounds. That automobile was uncovered to lower than a foot of the storm wake on the western coast of Florida and later caught fireplace, tragically destroying the house. This is not the primary time this we’ve seen a scenario like this. When hurricane Ian cruised by Florida two years in the past, there have been once more EV fires, together with one other Tesla Mannequin X.
You’ll be able to learn extra particulars on the issue in our reporting right here, however the gist of it’s that extended publicity to saltwater can breach the battery’s protecting seals. Shorts can type inside the pack, both instantly by the conductive saltwater, or by deposited salt after the water recedes. These shorts can then result in a thermal runaway situation.
EV fireplace numbers
Okay, let’s look into the basis of the factor: Are EVs actually fire-prone demise traps? There have been a number of research on the topic, and all come to the identical conclusion that electrical automobiles are far, far much less prone to combust than automobiles with inside combustion engines.
One of many extra complete research comes from Sweden’s Civil Contingencies Company (the MSB), which in 2022 cited 23 fires from a pool of 611,000 EVs in service. That compares to three,400 fires in 4.4 million fuel-burning automobiles. Do the maths, and 0.004 p.c of EVs caught fireplace that yr, in comparison with 0.08 p.c of ICE automobiles. (Word: That examine previously lived right here however is unfortunately offline. An archived model of the examine—although not in English—is out there right here. It has been cited by High Gear, IEEE Spectrum and The Guardian. All three are nice studying if you wish to be taught extra about this subject.)
It does not assist that EV fires are typically front-page information, regardless that they’re rarer than gasoline-vehicle fires. Nonetheless, they do pose distinctive challenges due to how laborious they are often to totally extinguish.
EV Hearth Secure, an Australian initiative for educating emergency responders about how you can work safely round EVs, carried out its personal survey and got here up with comparable numbers. In line with that analysis, between 2010 and 2020, a given EV had a 0.0012-percent likelihood of catching fireplace globally. ICE automobiles, nevertheless, had a 0.1-percent likelihood.
Lastly, the Norwegian Defence Analysis Institution (FFI) has a examine that takes a distinct tack, taking a look at insurance coverage claims for automobile fires. Over the interval between 2006 and 2016, EV fires made up simply 4.8 p.c of general automobile fires. Apparently, that quantity dropped considerably over the interval of examine. Taking a look at information from 2016, 2.3 p.c of car fires have been on account of EVs, seemingly pointing to newer automobiles being even safer.
And what about saltwater intrusion? The numbers are considerably more durable to trace since it is a uncommon phenomenon, however in line with NHTSA analysis, of the between 3,000 and 5,000 EVs have been at the very least partially submerged in salt water uncovered throughout hurricane Ian in 2022. 36 EVs caught fireplace, or lower than 0.01 p.c.
New methods for placing out EV fires
So, that conclusively reveals that EV fires are extraordinarily uncommon, however as defined above, they are often extremely violent after they do occur. What is the resolution? It’d require us re-thinking how we extinguish fires. The above video from Chilly Minimize Programs reveals one such approach.
As defined by CTIF, the Worldwide Affiliation of Hearth and Rescue Companies, the video reveals a method of penetrating ignited EV batteries and injecting water instantly into their inside construction. The result’s an EV battery put out in minutes, with solely a small fraction of the quantity of water that might in any other case be required.
Some specialised gear is required to make use of this system, however nothing extra unique than the Jaws of Life (extra formally, the Hurst Rescue Instruments), that are customary fare for emergency responders across the globe. And, not like these Jaws, this form of firefighting gear could be efficient for extinguishing different sorts of fires as nicely.
As EVs turn out to be extra prevalent, count on to see options like this spreading, too, making an already uncommon occasion far much less traumatic and harmful.
