Chances are high, by now, you have seen footage of an EV on fireplace. It is a fairly scary sight. Evil, black smoke rolling out from beneath the automobile, probably lit up by taking pictures 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 simple to suppose they’re occurring on a regular basis.
A high-profile Chevy Bolt recall associated to potential fireplace danger 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 nearly as good as enjoying with matches in a wooden shed.
But when that had 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 yr alone. What’s the true fact in regards to the fireplace 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 fireplace: A tiny little spark will do. Gasoline’s flamable nature makes it ideally suited to inside combustion, nevertheless it’s very completely happy for some exterior combustion, given half an opportunity.
Battery fires, nonetheless, are a bit extra nuanced. Your typical chemical cell in an EV is stuffed with unique parts that you could be be much less accustomed to, however the identical mixture of supplies that creates a remarkably energy-dense supply of energy in your automobile may also 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 main points, I extremely suggest you try “The Science of Fireplace and Explosion Hazards from Lithium-Ion Batteries” by Adam Barowy, analysis engineer at UL’s Fireplace Security Analysis Institute. It goes into far more element than I probably might right here.
However the gist of it’s that lithium-ion battery fires sometimes occur attributable to one thing known as thermal runaway. That is when a battery cell begins to achieve temperature sooner than it may possibly shed it. This will occur for quite a lot of causes, together with a flaw within the battery building, or a failure throughout charging.
It can be attributable to bodily harm to the cell, which could occur in a catastrophic crash or in the event 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 speedy launch of a whole lot of power.
Because the cell overheats and the power is launched, the interior parts throughout the battery start to interrupt down, together with the flammable electrolyte. It kicks off a form of incendiary chain response that will not cease till all the battery is consumed. These fires can burn for hours, even re-igniting after they have been extinguished.
Fortunately, there’s a whole lot 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 parts 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 means 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 throughout the pack, both immediately 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 automobiles are far, far much less more likely 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 fireplace that yr, in comparison with 0.08 p.c of ICE automobiles. (Notice: That research previously lived right here however is unfortunately offline. An archived model of the research—although not in English—is accessible right here. It has been cited by High 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, although they’re rarer than gasoline-vehicle fires. Nevertheless, they do pose distinctive challenges due to how onerous they are often to totally extinguish.
EV Fireplace Secure, an Australian initiative for educating emergency responders about find out how to 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 probability of catching fireplace globally. ICE automobiles, nonetheless, had a 0.1-percent probability.
Lastly, the Norwegian Defence Analysis Institution (FFI) has a research that takes a distinct tack, insurance coverage claims for car fires. Over the interval between 2006 and 2016, EV fires made up simply 4.8 p.c of total car fires. Curiously, that quantity dropped considerably over the interval of research. information from 2016, 2.3 p.c of car fires had been attributable to EVs, seemingly pointing to newer automobiles being even safer.
And what about saltwater intrusion? The numbers are considerably tougher to trace since it is a uncommon phenomenon, however in response to NHTSA analysis, of the between 3,000 and 5,000 EVs had 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 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 Lower Programs reveals one such approach.
As defined by CTIF, the Worldwide Affiliation of Fireplace and Rescue Companies, the video reveals a method of penetrating ignited EV batteries and injecting water immediately 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 form of firefighting tools could be efficient for extinguishing different sorts 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.
