Likelihood is, by now, you’ve got seen footage of an EV on fireplace. It is a fairly scary sight. Evil, black smoke rolling out from below 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 occurring on a regular basis.
A high-profile Chevy Bolt recall associated to attainable fireplace danger actually 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 pretty much 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? People purchased greater than a half-million EVs within the first half of this yr alone. What’s the true reality concerning 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 inside combustion, nevertheless it’s very comfortable for some exterior combustion, given half an opportunity.
Battery fires, nonetheless, are just a little extra nuanced. Your typical chemical cell in an EV is filled with unique parts that you could be be much less acquainted with, however the identical mixture of supplies that creates a remarkably energy-dense supply of energy in your automotive may 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 presumably might right here.
However the gist of it’s that lithium-ion battery fires usually occur as a consequence of one thing known as thermal runaway. That is when a battery cell begins to achieve temperature sooner than it could shed it. This may occur for a wide range of causes, together with a flaw within the battery development, or a failure throughout charging.
It can be brought on by bodily injury to the cell, which could occur in a catastrophic crash or in the event you occur to drive over particles that someway manages to pierce the cell. This may trigger a brief within the battery, leading to a really speedy launch of a whole lot of vitality.
Because the cell overheats and the vitality is launched, the interior parts 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 a whole lot of tech in fashionable batteries to stop that from occurring, 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 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 automotive 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 possibly can 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 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 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 % of EVs caught fireplace that yr, in comparison with 0.08 % of ICE automobiles. (Notice: That examine previously lived right here however is unfortunately offline. An archived model of the examine—although not in English—is on the market 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 would not assist that EV fires are usually front-page information, despite the fact that they’re rarer than gasoline-vehicle fires. Nevertheless, 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 the right way to work safely round EVs, performed its personal survey and got here up with comparable numbers. In accordance 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 examine that takes a special tack, taking a look at insurance coverage claims for car fires. Over the interval between 2006 and 2016, EV fires made up simply 4.8 % of general car fires. Curiously, that quantity dropped considerably over the interval of examine. Taking a look at information from 2016, 2.3 % of auto fires have been as a consequence of EVs, seemingly pointing to more moderen 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 %.
New methods for placing out EV fires
So, that conclusively exhibits 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 Techniques exhibits one such method.
As defined by CTIF, the Worldwide Affiliation of Hearth and Rescue Companies, the video exhibits a method of penetrating ignited EV batteries and injecting water straight 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 normal 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 nicely.
As EVs develop into extra prevalent, anticipate to see options like this spreading, too, making an already uncommon occasion far much less traumatic and harmful.
