Chances are high, by now, you’ve got seen footage of an EV on hearth. It is a reasonably scary sight. Evil, black smoke rolling out from underneath 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 assume they’re occurring on a regular basis.
A high-profile Chevy Bolt recall associated to potential hearth danger actually 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 had 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 hearth 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 hearth: A tiny little spark will do. Gasoline’s flamable nature makes it ideally fitted to inner combustion, however it’s very blissful 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 on your automobile may create the right storm for a very ugly hearth.
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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 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 usually occur attributable to one thing known as thermal runaway. That is when a battery cell begins to achieve temperature sooner than it may 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 harm to the cell, which could occur in a catastrophic crash or for those who occur to drive over particles that one way or the other manages to pierce the cell. This could trigger a brief within the battery, leading to a really speedy launch of loads of power.
Because the cell overheats and the power is launched, the interior elements inside the battery start to interrupt down, together with the flammable electrolyte. It kicks off a kind of incendiary chain response that will not cease till the complete battery is consumed. These fires can burn for hours, even re-igniting after they have been extinguished.
Fortunately, there’s loads of tech in trendy 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 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 automobile 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 by 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 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 hearth 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 prone to combust than automobiles 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 automobiles. Do the mathematics, and 0.004 % of EVs caught hearth that yr, in comparison with 0.08 % 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 offered 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 usually front-page information, regardless that they’re rarer than gasoline-vehicle fires. Nonetheless, they do pose distinctive challenges due to how exhausting they are often to totally 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 hearth globally. ICE automobiles, nevertheless, had a 0.1-percent likelihood.
Lastly, the Norwegian Defence Analysis Institution (FFI) has a research that takes a distinct tack, insurance coverage claims for automobile fires. Over the interval between 2006 and 2016, EV fires made up simply 4.8 % of general automobile fires. Apparently, that quantity dropped considerably over the interval of research. knowledge from 2016, 2.3 % 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 accordance with 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 hearth, 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 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 exhibits one such method.
As defined by CTIF, the Worldwide Affiliation of Hearth and Rescue Companies, the video exhibits 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 tools 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 commonplace fare for emergency responders across the globe. And, in contrast to these Jaws, this kind of firefighting tools will be efficient for extinguishing different sorts of fires as properly.
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.
