Likelihood is, by now, you’ve got seen footage of an EV on hearth. It is a reasonably scary sight. Evil, black smoke rolling out from beneath the automotive, presumably lit up by capturing sparks and ceaseless flames that seemingly no quantity of water can extinguish. These fires are so typically highlighted on the information and social media that it is easy to suppose they’re taking place on a regular basis.
A high-profile Chevy Bolt recall associated to doable hearth danger definitely hasn’t helped that public notion, offering ever extra ammunition to anti-EV pundits who’d have you ever consider that parking an electrical automotive in your storage is nearly as good as taking part in with matches in a wooden shed.
But when that have been the reality, would not we be seeing a heck of much more fires? Individuals purchased greater than a half-million EVs within the first half of this 12 months alone. What’s the actual fact concerning the hearth danger of EVs? That is what we’re right here to seek 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 hearth: A tiny little spark will do. Gasoline’s flamable nature makes it ideally fitted to inside combustion, nevertheless it’s very glad for some exterior combustion, given half an opportunity.
Battery fires, nevertheless, are a little bit extra nuanced. Your typical chemical cell in an EV is filled with unique elements that you could be be much less accustomed to, however the identical mixture of supplies that creates a remarkably energy-dense supply of energy to your automotive may create the proper storm for a extremely ugly hearth.
YouTube
A gaggle of Teslas broken in a hearth in Germany.
To get all the small print, I extremely advocate you take a look at “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 presumably may right here.
However the gist of it’s that lithium-ion battery fires sometimes occur as a result of one thing referred to as thermal runaway. That is when a battery cell begins to realize temperature sooner than it might probably shed it. This could occur for quite a lot of causes, together with a flaw within the battery development, or a failure throughout charging.
It will also be attributable to bodily injury to the cell, which could occur in a catastrophic crash or for those who occur to drive over particles that in some way manages to pierce the cell. This could trigger a brief within the battery, leading to a really speedy launch of plenty of power.
Because the cell overheats and the power is launched, the interior elements throughout the battery start to interrupt down, together with the flammable electrolyte. It kicks off a type 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 plenty of tech in fashionable batteries to stop that from taking place, together with superior thermal administration and big quantities of crash safety, just like the carbon-fiber underbody safety within the electrical Mercedes-Benz G-Class, or the aluminum extrusions and solid 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 hearth has been making the rounds. That automotive was uncovered to lower than a foot of the storm wake on the western coast of Florida and later caught hearth, tragically destroying the house. This is not the primary time this we’ve seen a state of affairs like this. When hurricane Ian cruised via Florida two years in the past, there have been once more EV fires, together with one other Tesla Mannequin X.
You may 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 kind throughout 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 hearth numbers
Okay, let’s look into the basis of the factor: Are EVs actually fire-prone loss of life 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 mathematics, and 0.004 p.c of EVs caught hearth that 12 months, in comparison with 0.08 p.c of ICE automobiles. (Observe: That examine previously lived right here however is unfortunately offline. An archived model of the examine—although not in English—is obtainable right here. It has been cited by Prime Gear, IEEE Spectrum and The Guardian. All three are nice studying if you wish to study extra about this subject.)
It does not assist that EV fires are typically front-page information, despite the fact that they’re rarer than gasoline-vehicle fires. Nevertheless, they do pose distinctive challenges due to how onerous they are often to completely extinguish.
EV Hearth Protected, an Australian initiative for educating emergency responders about how one can work safely round EVs, performed its personal survey and got here up with comparable numbers. Based on that analysis, between 2010 and 2020, a given EV had a 0.0012-percent probability of catching hearth globally. ICE automobiles, nevertheless, had a 0.1-percent probability.
Lastly, the Norwegian Defence Analysis Institution (FFI) has a examine that takes a special tack, insurance coverage claims for automobile fires. Over the interval between 2006 and 2016, EV fires made up simply 4.8 p.c of total automobile fires. Apparently, that quantity dropped considerably over the interval of examine. Taking a look at knowledge from 2016, 2.3 p.c of auto fires have been as a result 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 no less than partially submerged in salt water uncovered throughout hurricane Ian in 2022. 36 EVs caught hearth, or lower than 0.01 p.c.
New strategies 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 answer? 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 tools 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 type of firefighting tools may be efficient for extinguishing different varieties of fires as effectively.
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.
