Chances are high, by now, you’ve got seen footage of an EV on fireplace. It is a reasonably scary sight. Evil, black smoke rolling out from underneath the automobile, presumably 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 suppose they’re taking place on a regular basis.
A high-profile Chevy Bolt recall associated to attainable fireplace 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 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? Individuals purchased greater than a half-million EVs within the first half of this 12 months alone. What’s the true fact in regards to the fireplace danger 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 inner combustion, but it surely’s very completely satisfied for some exterior combustion, given half an opportunity.
Battery fires, nevertheless, are slightly 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 may create the right storm for a very ugly fireplace.
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A bunch of Teslas broken in a hearth in Germany.
To get all the small print, I extremely suggest 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 presumably might right here.
However the gist of it’s that lithium-ion battery fires usually occur as a consequence of one thing referred to as thermal runaway. That is when a battery cell begins to realize temperature quicker than it may well shed it. This will occur for quite a lot of causes, together with a flaw within the battery development, or a failure throughout charging.
It can be attributable to bodily harm to the cell, which could occur in a catastrophic crash or if you happen to occur to drive over particles that one way or the other manages to pierce the cell. This will trigger a brief within the battery, leading to a really fast launch of numerous 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 type of incendiary chain response that won’t cease till the whole battery is consumed. These fires can burn for hours, even re-igniting after they have been extinguished.
Fortunately, there’s numerous tech in fashionable batteries to forestall that from taking place, 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 way of 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 straight 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 foundation 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 vehicles are far, far much less more likely to combust than vehicles with inner 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 vehicles. Do the maths, and 0.004 p.c of EVs caught fireplace that 12 months, in comparison with 0.08 p.c of ICE vehicles. (Word: 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 be taught extra about this subject.)
It does not assist that EV fires are usually front-page information, regardless that they’re rarer than gasoline-vehicle fires. Nevertheless, they do pose distinctive challenges due to how laborious they are often to completely extinguish.
EV Hearth Secure, an Australian initiative for educating emergency responders about easy methods to work safely round EVs, carried out its personal survey and got here up with related numbers. In keeping with that analysis, between 2010 and 2020, a given EV had a 0.0012-percent likelihood of catching fireplace globally. ICE vehicles, 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. Curiously, that quantity dropped considerably over the interval of examine. Taking a look at knowledge from 2016, 2.3 p.c of car fires have been as a consequence of EVs, seemingly pointing to newer vehicles being even safer.
And what about saltwater intrusion? The numbers are considerably more durable to trace since it is a uncommon phenomenon, however in keeping with NHTSA analysis, of the between 3,000 and 5,000 EVs have been a minimum of 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 once they do occur. What is the resolution? It’d require us re-thinking how we extinguish fires. The above video from Chilly Lower Programs reveals one such approach.
As defined by CTIF, the Worldwide Affiliation of Hearth and Rescue Companies, the video reveals a way of penetrating ignited EV batteries and injecting water straight into their inner construction. The result’s an EV battery put out in minutes, with solely a small fraction of the quantity of water that will in any other case be required.
Some specialised gear is required to make use of this method, 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, in contrast to these Jaws, this type of firefighting gear could be efficient for extinguishing different varieties of fires as properly.
As EVs change into extra prevalent, anticipate to see options like this spreading, too, making an already uncommon occasion far much less traumatic and harmful.
