Electric and Hydrogen Vehicles

[atpollard]

“From 2012 – 2020, there has been approximately one Tesla vehicle fire for every 205 million miles traveled. By comparison, data from the National Fire Protection Association (NFPA) and U.S. Department of Transportation shows that in the United States there is a vehicle fire for every 19 million miles traveled.”

Interesting what happens when you compare fires per mile travelled instead of just “per 100,000 vehicles”. Apparently it is more of a fire danger to DRIVE an ICE car that to PARK an EV car.

FYI, 46% of IC vehicle fires are from the electrical wiring (which is nearly identical on an EV), so more EV use will see more EV electrical fires in the vehicle wiring and narrow that “per 100,000 vehicle” gap.

 

[Spinward Flow]

“From 2012 – 2020, there has been approximately one Tesla vehicle fire for every 205 million miles traveled. By comparison, data from the National Fire Protection Association (NFPA) and U.S. Department of Transportation shows that in the United States there is a vehicle fire for every 19 million miles traveled.”

Or to put it another way, Tesla vehicles are 205/19=10.789x less likely to catch fire than the average car.

Apparently it is more of a fire danger to DRIVE an ICE car that to PARK an EV car.

True ... although it depends on the brand of vehicle manufacturer (and their parts suppliers). Some manufacturers source from parts/build their products in ways that are more likely to catch fire than is "preferable by the consumer" ... hence advisories to park some brands of EVs away from structures (or anything else that can burn, really) due to poor engineering design and quality control during production.

A different way of making this point ... that some manufacturers produce fewer defective products (which then require recalls) ... can be seen in a different data set that has nothing to do with fire risks (so tangential topic shift).

Source: LINK

In order, the automakers with the most U.S. recall campaigns in 2025 were:

1. Ford Motor Company – 152 recalls
2. Stellantis (Chrysler, Dodge, Jeep, Ram) – 53 recalls
3. General Motors – 27 recalls
4. Volkswagen – 24 recalls
5. Mercedes-Benz – 21 recalls
6. Honda – 21 recalls
7. BMW – 21 recalls
8. Hyundai – 21 recalls
9. Toyota – 15 recalls
10. Tesla – 11 recalls

If you calculate the average of those 10 manufacturers, you get this result:

• 152+53+27+24+21+21+21+21+15+11 = 366 / 10 = 36.6 recalls per manufacturer in 2025 on average

However, two manufacturing brands were obviously higher than average ... Ford (4.15x) and Stellantis (1.45x) ... in the above chart, so make of that what you will.

Take the "skew" in the average due to the outliers (Ford and Stellantis) out of the mix and with the remaining 8 manufacturers you get this as the average for 2025:

• 27+24+21+21+21+21+15+11 = 161 / 8 = 20.125 recalls per manufacturer in 2025 on average.

By this standard, Toyota and Tesla were the only companies with fewer recalls than the (truncated) average that omitted the top two offenders outliers.



Something similar is going on with battery chemistries (specifically, NMC chemistries based on Nickel Manganese Cobalt) are more fire prone than others, some battery form factors are more fire prone than others ("pouch" cells rather than blades or cylindrical "can" cells) and a lot of other factors that go into the fire risks of battery engineering.

Fortunately, newer LFP (Lithium Iron Phosphate) batteries are lower power density than NMC (so higher weight for the same capacity) but are far less fire prone. China has promulgated new regulations around fire prevention testing/validation of batteries intended for use in vehicles to improve safety around battery combustion issues, including what amounts to basically "not allowed to catch fire even when damaged/pierced" and a bunch of other testing regimens to prove fire safety. Sodium based chemistries are also a lot less likely to catch fire ... so there are a lot of advancements in engineering fire prevention into newer battery designs.

 

[aramis]

The problem with hydrogen (as a power source) is that it doesn't appear as "something that can be mined" in pockets of H₂ gas "conveniently lying around, ready to be pumped" from any natural sources. Hydrogen almost ALWAYS appears in molecular form bound to other elements (H₂O, CH₄, NH₃, etc. etc. etc. etc. etc.), meaning that in order to "get at" the H₂ you have to "crack" the molecules you're wanting to source it from ... which means energy input just to make the hydrogen you want to use.

Then there's the Storage Problem™.
Hydrogen is the smallest "stuff" in the universe ... meaning is can permeate through ALMOST EVERYTHING made of other elements/molecules ... so it "leaks" out of storage REALLY EASILY.

there's the further issue that molecular hydrogen is below earth's minimum molecular weight which it can gravitationally retain. It rises up to the solar shock and gets blown away with the solar wind. That's largely why any pockets of hydrogen venting are of limited risk.. and are rare.

This does, however, make hydrogen fuel cells a touch safer than lithium batteries in that the fire goes up, rather than staying in the storage medium, in earth atmosphere. If it doesn't have the stoichiometric range of concentration to explode, you can escape the flaming wreck because the flames will be shooting up. Meanwhile, lithium batteries are largely self-oxidizing and will strip oxygen from water to burn... (see What's Going On With Shipping's discussion of the burning motor carriers a couple months back).

From an infrastructural standpoint, it's safer to have hydrogen fuel cell vehicles on the roads than the Lithium Hydroxide (LiOH) cells so common now.

Pierce a hydrogen storage cell, it usually leaks out up to the penetration, and unless above 500°C, simply finds its way upward.
Pierce a typical lithium cell, it self-ignites and self-oxidizes, and produces hazmat smoke.

It's not all about the energy efficiency.

 

[Spinward Flow]

Pierce a hydrogen storage cell, it usually leaks out up to the penetration, and unless above 500°C, simply finds its way upward.

If you've got a nice stable medium to store the hydrogen in (such as a metal) then the penetration won't yield much in the way of Bad Stuff™ when penetrated (such as the "nail test").

If however, you've got a pressure vessel keeping hydrogen gaseous at high pressure ... piercing the storage method might not be flammable (immediately), but it will probably be "propulsively dangerous" the same way that a pierced high pressure tank of any other material would be (think rocket thrust pressure cylinder).

But yes, the 1G surface gravity of Terra is insufficient to retain gaseous hydrogen in the atmosphere long term.

It's not all about the energy efficiency.

True.
In engineering it's the balance of trade offs that determines the optimal choice from a range of options.

 

[Condottiere]

I'm a tiny bit concerned about that, with my air/ships.

However, that does raise the question if you can adjust the fuel processor to create helium, and use that as a fuel, not just for lift.

 

[Rupert]

If you've got a nice stable medium to store the hydrogen in (such as a metal) then the penetration won't yield much in the way of Bad Stuff™ when penetrated (such as the "nail test").

If however, you've got a pressure vessel keeping hydrogen gaseous at high pressure ... piercing the storage method might not be flammable (immediately), but it will probably be "propulsively dangerous" the same way that a pierced high pressure tank of any other material would be (think rocket thrust pressure cylinder).

But yes, the 1G surface gravity of Terra is insufficient to retain gaseous hydrogen in the atmosphere long term.

True.
In engineering it's the balance of trade offs that determines the optimal choice from a range of options.

Liquid Hydrogen will initially just flow out the hole, freezing everything it touches until it vaporises, at which point it'll mix with the local atmosphere. Fortunately, hydrogen/air mixes tend to burn rather than explode, and compared to hydrocarbons hydrogen gas doesn't have a very high energy density per unit volume. There also won't be massive puddles lying round fuelling continuous fires, though once a leaking tank starts warming up it could supply a continuous flame (and possibly thrust, which could add to the excitement), depending on air supply. Compared with a leaking petrol tank the fire is comparatively 'safe', as I understand it. The initial cryogenic spill is not something you'd want to be involved in, though.

 

[atpollard]

Or to put it another way, Tesla vehicles are 205/19=10.789x less likely to catch fire than the average car.

You are correct ... I admit that I misread that statistic.
[See, I CAN admit when I am wrong. ]

 

[Spinward Flow]

I'm a tiny bit concerned about that, with my air/ships.

Hydrogen (gas) is ... relatively safe in large ambient pressure volumes (such as an airship envelope). The problem is, what do you make the envelope to contain the hydrogen gas in?

The reason why the Hindenburg went up in the flames the way it did was because the fabric skin of the zepplin was impregnated with aluminum dust ... which not coincidentally is the same material used to augment the thrust of solid rocket motors and increase the heat of thermal explosive bombs ... so not exactly something you want to be "plentiful" in the fabric skin of your airship (if something goes wrong in the flammable sense). Nylon "fabrics" hadn't been invented yet in the late 1920s/early 1930s, so that material wasn't available yet for engineering use (nylon was one of the inventions made during world war 2) and the first product made from nylon was stockings in 1940 (which women the world over couldn't get enough of for decades thereafter).

The other problem is that at ambient temperature/pressure, hydrogen+oxygen flames are not visible in optical light (unless contaminated with other burning materials), so you basically need thermographic infrared sensors to be able to see (more or less) pure hydrogen burning with human eyes.

With an airship, the big risk with hydrogen lift gas is the ignition source ... either thermal (open flame) or electrical (discharge) ... that can initiate a fire. Static electric buildup on airship envelopes can be a serious hazard when near grounding points ... such as mooring stations and landing fields ... which depending on the engineering of construction and materials used can result in "unsafe static discharges" when making contact.

The other major risk for airships is ... weather.
Being such large volume combined with low density (because, net lighter than air in order to generate lift) means that you get large surface areas for ambient winds to "push" against and induce drag forces on. This is why early airships required such enormous landing zones (so they could "wind sock" orient with currently prevailing wind conditions) and huge numbers of personnel to manage mooring captures (you needed that many people just to "wrangle" the airship safely). Airships, of any variety, are very much "fair weather flyers" ... while heavier than air, fixed wing aircraft can be engineered to work as "foul weather flyers" which makes things like Hurricane Hunters possible with fixed wing aircraft, but not airships.

 

[Spinward Flow]

Liquid Hydrogen will initially just flow out the hole, freezing everything it touches until it vaporises, at which point it'll mix with the local atmosphere.

The boiling point of liquid hydrogen at ambient 1 atmosphere pressure is 20.28 Kelvin ... which is COLD!
But it doesn't take a tremendous amount of thermal input to raise the temperature above that when leaking into a shirt sleeves environment, causing the hydrogen to boil and phase transition from liquid to gas state. However, the 20.28K temperature is low enough for nitrogen and oxygen gasses to freeze solid when transferring thermal energy to the hydrogen.

However, when hydrogen changes state from liquid to gas, it expands by a factor of 848-850x ... so boil off in a sealed container without a means to vent overpressure will result in ruptures of containers (at some point) that have an external pressure of 1 atmosphere (or lower) around them.

Liquid hydrogen requires specialized handling (materials, procedures, engineering, etc.) to work with and maintain.
It's not like "a glass of water" by any stretch of the imagination.

 

[Spinward Flow]

However, that does raise the question if you can adjust the fuel processor to create helium, and use that as a fuel, not just for lift.

Not ... really ... no ...
The problem with your postulate is the word ... CREATE.
If you can CREATE helium ... then there's no problem.
If what you meant is to "refine" helium out of the input feedstocks ... there's a huge problem.

Helium is a noble gas. It doesn't like to create molecular bonds with ANYTHING ... including itself.
It's also "lighter than air" on Terra, so just like with hydrogen any helium released into the atmosphere will rise up into space and be lost to the solar wind.

In the real world, helium is a waste byproduct of fossil fuel production ... because helium has to be trapped underground (in the lithosphere) in order to "contain" it in the terrestrial environment. Helium is actually a result of nuclear fission decay processes (alpha particle emission) of heavier elements that has gone on long enough to produce concentrations of the material locked up in underground repositories. So when you drill for petroleum or natural gas, a fraction of what you bring up to the surface has helium in it which then needs to be separated out as part of the purification process for those hydrocarbon fuels (since helium doesn't oxydize/burn it's "not useful" in the petroleum industry's main products).

To put it mildly, in a terrestrial environment, helium is not something that you're going to be able to purify out of a wilderness refueling cycle.

That changes when you're talking about orbital skimming gas giant atmospheres (Jupiter, Saturn) which ARE able to retain helium gas in their atmospheres (in plentiful quantities!) ... but "airships" in the atmospheres of gas giants isn't exactly what I think you're angling for so ... not exactly a "useful source" of helium gas for low tech airships (per se), except perhaps for novelty/tourist trap reasons.



The main problem is that helium needs to be IN the fuel source that you're wanting to process.
In Traveller terms, that's either limited to gas giant scooping or to lithosphere drilling extraction industries as potential sources for helium.

 

[Enoki]

Not ... really ... no ...
The problem with your postulate is the word ... CREATE.
If you can CREATE helium ... then there's no problem.
If what you meant is to "refine" helium out of the input feedstocks ... there's a huge problem.

Helium is a noble gas. It doesn't like to create molecular bonds with ANYTHING ... including itself.
It's also "lighter than air" on Terra, so just like with hydrogen any helium released into the atmosphere will rise up into space and be lost to the solar wind.

In the real world, helium is a waste byproduct of fossil fuel production ... because helium has to be trapped underground (in the lithosphere) in order to "contain" it in the terrestrial environment. Helium is actually a result of nuclear fission decay processes (alpha particle emission) of heavier elements that has gone on long enough to produce concentrations of the material locked up in underground repositories. So when you drill for petroleum or natural gas, a fraction of what you bring up to the surface has helium in it which then needs to be separated out as part of the purification process for those hydrocarbon fuels (since helium doesn't oxydize/burn it's "not useful" in the petroleum industry's main products).

To put it mildly, in a terrestrial environment, helium is not something that you're going to be able to purify out of a wilderness refueling cycle.

That changes when you're talking about orbital skimming gas giant atmospheres (Jupiter, Saturn) which ARE able to retain helium gas in their atmospheres (in plentiful quantities!) ... but "airships" in the atmospheres of gas giants isn't exactly what I think you're angling for so ... not exactly a "useful source" of helium gas for low tech airships (per se), except perhaps for novelty/tourist trap reasons.



The main problem is that helium needs to be IN the fuel source that you're wanting to process.
In Traveller terms, that's either limited to gas giant scooping or to lithosphere drilling extraction industries as potential sources for helium.

On the other hand...

You might be extracting it as a byproduct of running your fusion plant on a ship or whatever. That is essentially what you are making to get the energy you need to run the ship...

Now, if you can get enough from that process is an entirely different question...

 

[Spinward Flow]

You might be extracting it as a byproduct of running your fusion plant on a ship or whatever. That is essentially what you are making to get the energy you need to run the ship...

True ... but ... the quantities of helium being produced as a "waste product" from the fusion reaction are not ... tremendous. It's not the nuclear equivalent to a desalination plant generating millions of liters of fresh water per day.

Yes, fuel consumption rates (especially at vehicle scales) are rated in terms of liters per hour per megawatt ... but how much of that fuel consumption rate is being "burned" in the fusion reactor itself, fusing hydrogen into helium? The real answer is probably going to be ... remarkably little ... like maybe on the order of (milli?)grams of hydrogen per hour, with the rest being used as coolant/thermal control conductivity. Just speculating, but it's broadly the same idea as how jump fuel requirements work. Most of the fuel tankage required to jump isn't fused for power, but rather used as a thermal heat sink (and rapidly ejected overboard) to prevent the aggressive fusion reaction from thermally destroying the starship's delicate engineering. Apply the same concept (albeit at a lower scale) to ordinary "nominal" operation of fusion power plants and you're at least following a congruent trajectory in terms of lines of thinking about the topic.

Point being that the amount of helium generated by fusion reactors is certainly going to be a measurable positive number value ... but unless you're talking about the biggest fusion power plant installations, the production rate of helium from the fusion reactions is going to be "pretty pitiful" on the macroscopic scale (which likes to measure things in kg and multiples of kg).

In small/big craft, I would fully expect the "waste helium" produced by the fusion reactor to be extremely high temperature/energetic ("freshly fused!") and thus best rejected overboard as part of a HEPlaR type maneuver drive exhaust system.

 

[Condottiere]

1. Exchange blimp gas envelope for fuel bladder.

2. Maybe, speeded up radioactive decay to create helium; we do have nuclear dampers, that could be tweaked.

 

[Spinward Flow]

2. Maybe, speeded up radioactive decay to create helium; we do have nuclear dampers, that could be tweaked.

If you've got the tech for nuclear dampeners ... you've got the tech for gravitics.
No need for lighter than air buoyancy workarounds then.