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There's actually no need for hydrogen. Helium would do just fine. From the blog post, filling the hypothetical airship with helium would cost $8 MM, while filli

There's actually no need for hydrogen. Helium would do just fine. From the blog post, filling the hypothetical airship with helium would cost $8 MM, while filling it with hydrogen would cost only $100k. Sounds like a no brainer. But, the overall cost of the airship would be at $100 MM. Hydrogen would result in a less than 10% cost reduction. Now, the FAA approved unleaded jet fuel in 2022. Yes, that's how conservative FAA is. We'll sooner achieve world peace than the FAA would approve hydrogen for airships.

tiagod 4y ago
Preventing the helium from leaking out of wherever its stored is challenging, it's not a "fill once and forget about it" kind of deal. Helium is bound to get more expensive too.
jodrellblank 4y ago
Helium is a non-renewable resource drilled out of the ground, of which there is a global 'crisis' shortage[1]. Hydrogen is easy to make in vast quantities and cheaper. But more importantly, while they have similar lift capacities on paper (Helium ~90% of Hydrogen), in practice they don't - https://www.airships.net/helium-hydrogen-airships/ https://www.airships.net/helium-hydrogen-airships/ has an explanation and calculations. Hydrogen lift airships set off fully inflated and vent Hydrogen along the way for control of altitude and to stop their lift cells expanding too much as they rise into lower pressure air; Helium is too expensive to vent casually, so they have to start less inflated to protect the lift cells, and other concerns so Helium lift ends up with half the payload carrying capacity, less fuel, shorter flight distances. And, nb. the deadliest airship disaster was the USS Akron which was was a Helium lift airship which crashed in a storm with 73 deaths and 3 survivors. It's not as simple as Hydrogen = danger, Helium = safe. [1] https://www.forbes.com/sites/omerawan/2022/11/10/the-helium-crisis-how-it-will-affect-you-and-your-loved-ones/ https://www.forbes.com/sites/omerawan/2022/11/10/the-helium-...
- triceratops 4y ago
  If fusion power takes off, could you produce helium as a by-product?
  - aae42 4y ago
    if we figured out fusion, it would alter the economics of all of this why not fusion powered ships/trains/airplanes
    - worik 4y ago
      > why not fusion powered ships/trains/airplanes[?] What could possibly go wrong?
      - chrisco255 4y ago
        We already have fission powered ships and submarines.
        jodrellblank 4y ago
        We almost had fission powered airplanes and airships: https://en.wikipedia.org/wiki/Nuclear-powered_aircraft https://en.wikipedia.org/wiki/Nuclear-powered_aircraft and https://en.wikipedia.org/wiki/Lockheed_CL-1201 https://en.wikipedia.org/wiki/Lockheed_CL-1201 And dreams of fission trains: https://twsmedia.co.uk/2020/05/09/atomic-trains/ https://twsmedia.co.uk/2020/05/09/atomic-trains/
        worik 4y ago
        Sense prevailed, and we do not have civilian mobile nuclear reactors. The military are mad. Mad and bad. It is in the job description. We would all be better off if none of them (the military) existed
      - jasamer 4y ago
        Afaik what makes fusion hard is maintaining the conditions that allow fusion to occur. Because of this, it’s quite safe - if anything goes wrong, it’ll just stop working.
- moffkalast 4y ago
  Yeah hydrogen sounds like it could even be safer given that you get a larger buoyancy buffer to fight downdrafts? It's a real public misconception that it just explodes from all those oxyhydrogen experiments at chemistry class, but pure hydrogen such as in airships just slowly burns, much like any other fuel we fill our planes with. The main problem is still that you need to contain a large volume, which will inevitably get pushed around by wind more than you can compensate for.
- pkulak 4y ago
  I wonder if you could use a fuel cell to get power from the hydrogen you'd otherwise vent.
BeefySwain 4y ago
You may have overlooked the part where filling the quantity of airships that would (theoretically) be used would represent over half of the KNOWN quantity exploitable on earth, and would take decades to produce at current production rates. Also, they would need topped up over time. Compared to hydrogen, which is cheap, available, and renewable.
- credit_guy 4y ago
  > KNOWN quantity exploitable on earth It's great that you emphasized "known". Knowledge is not a static thing. Also what's economically exploitable is a variable thing. Currently, the US produces 40% of the world's helium, despite producing only 25% of the world's natural gas. Is it because the US has drawn a lucky lottery ticket for helium? That's very unlikely. Helium is being produced continuously inside Earth as the alpha particles generated during the radioactive decay of some elements (mainly Uranium and Thorium, but Radon too). It seeps upward, and it generally escapes in the atmosphere, but some of it gets trapped in the same geological formations that trap natural gas. In most places people don't bother to see how much helium there is in natural gas. They just sell the gas and take the money. Separating helium can increase the profitability a bit, but it depends on how cheaply you can do the separation. It's very likely that the US has better technology than the rest of the world, and because of that it separates more helium for the same quantity of natural gas. As the technology will spread out, more helium will become recoverable. Also, it may come as a tautology, but more helium is economically recoverable if its price goes up.
mikepurvis 4y ago
As a noble gas, helium can't be synthesized, so its cost is because of its scarcity— and because it's a small molecule (like hydrogen), you inevitably lose some and require continuous top-ups. None of this sounds like it would be realistic at scale, no matter the amount of money in play.
kortilla 4y ago
The FAA approved modifications to piston engines to use unleaded avgas. Jet fuel doesn’t have lead. Also, this isn’t about the FAA just being slow for no reason. Switching from leaded to unleaded without the engine modifications was not safe for the piston aircraft that need it. https://en.wikipedia.org/wiki/Jet_fuel https://en.wikipedia.org/wiki/Jet_fuel https://en.wikipedia.org/wiki/Avgas https://en.wikipedia.org/wiki/Avgas
- coryrc 4y ago
  It's not safe for us to be breathing. But that doesn't matter to cheapskate rich private plane owners or their regulatory-captured FAA.
  - LarryMullins 4y ago
    The really rich private plane owners all have planes that burn jet fuel, which is always unleaded. The piston planes are generally owned by "doctor rich" upper-middle class people, who have political influence to be sure but they're hardly the billionaires that might be known by name to politicians. I think it's more likely that the FAA protects general aviation because general aviation is part of the professional pilot training pipeline.
    - coryrc 4y ago
      [flagged]
      - LarryMullins 4y ago
        > Ah, if you're only "doctor rich" then it's okay to poison children! That's not what I said and you know it. > GA is responsible for 50% of lead emissions! Little lead is emitted at all these days, because leaded gasoline was banned in almost all circumstances. So you're talking about 50% of "not much". I'd be happy to see it banned completely since there are now viable alternatives, but I think you're going a little bit too hard with this class war narrative.
    - 4y ago
TylerE 4y ago
Lift gas is a consumable. You have to vent it to descend in many cases, and that’s ignoring the inevitable leaks and diffusion.
- worik 4y ago
  > Lift gas is a consumable. You have to vent it to descend in many cases, and that’s ignoring the inevitable leaks and diffusion Helium blimps compression the gas to lower buoyancy
kurthr 4y ago
So, if filling your gas tank cost 8% of the price of your car... you'ld think nothing of it? Lift gas leaks (esp He) and gets vented. So this seems odd to me. It's kinda like buying your car again every few months to a year or paying $250/gal to fill up. Now 80x lower at 0.1% of the car price you're in the regime where it's negligible like an EV.
- LarryMullins 4y ago
  > Lift gas leaks (esp He) Hydrogen more than helium, I believe.
  - kurthr 4y ago
    Each Hydrogen molecule is more reactive, but actually a larger molecule (less leaky) because there are two (it's diatomic H2 rather than monoatomic He). Now it does get complicated, because the simple atomic radii aren't sufficient when you start bouncing around and leaking through other materials, but suffice it to say that He is still smaller once you look at the Vander Walls attraction and everything. It may only be 10% smaller, but that leads to at least a 20% lower leak rate. https://bbblimp.com/2021/09/17/helium-vs-hydrogen-atom-size/ https://bbblimp.com/2021/09/17/helium-vs-hydrogen-atom-size/
dwighttk 4y ago
Author mentioned a market for 25K of these airships, which is like half the helium on earth the first time you fill them up. $8M will go up once you start building
dspillett 4y ago
> Helium would do just fine. Though that creates another problem: there is a shortage of Helium developing that is starting to cause concerts in a few places (like medical imaging, which it is used as a coolant for devices like MRI scanners). That $8E6 might grow significantly not long after the first airships roll off the production line, and it'll raise for other users significantly too as available supply becomes more contested. > There's actually no need for hydrogen. The Hindenburg was originally designed with Helium in mind, but because of a US export ban (at the time Helium was in even shorter supply, and most of it was being produced from resources in the US) forced a redesign. Unless new practical+affordable sources are found, the same sort of design limitations could strike again.

tiagod 4y ago

Preventing the helium from leaking out of wherever its stored is challenging, it's not a "fill once and forget about it" kind of deal. Helium is bound to get more expensive too.

jodrellblank 4y ago

Helium is a non-renewable resource drilled out of the ground, of which there is a global 'crisis' shortage[1]. Hydrogen is easy to make in vast quantities and cheaper. But more importantly, while they have similar lift capacities on paper (Helium ~90% of Hydrogen), in practice they don't - https://www.airships.net/helium-hydrogen-airships/ https://www.airships.net/helium-hydrogen-airships/ has an explanation and calculations. Hydrogen lift airships set off fully inflated and vent Hydrogen along the way for control of altitude and to stop their lift cells expanding too much as they rise into lower pressure air; Helium is too expensive to vent casually, so they have to start less inflated to protect the lift cells, and other concerns so Helium lift ends up with half the payload carrying capacity, less fuel, shorter flight distances. And, nb. the deadliest airship disaster was the USS Akron which was was a Helium lift airship which crashed in a storm with 73 deaths and 3 survivors. It's not as simple as Hydrogen = danger, Helium = safe. [1] https://www.forbes.com/sites/omerawan/2022/11/10/the-helium-crisis-how-it-will-affect-you-and-your-loved-ones/ https://www.forbes.com/sites/omerawan/2022/11/10/the-helium-...

triceratops 4y ago
If fusion power takes off, could you produce helium as a by-product?
- aae42 4y ago
  if we figured out fusion, it would alter the economics of all of this why not fusion powered ships/trains/airplanes
  - worik 4y ago
    > why not fusion powered ships/trains/airplanes[?] What could possibly go wrong?
    - chrisco255 4y ago
      We already have fission powered ships and submarines.
      - jodrellblank 4y ago
        We almost had fission powered airplanes and airships: https://en.wikipedia.org/wiki/Nuclear-powered_aircraft https://en.wikipedia.org/wiki/Nuclear-powered_aircraft and https://en.wikipedia.org/wiki/Lockheed_CL-1201 https://en.wikipedia.org/wiki/Lockheed_CL-1201 And dreams of fission trains: https://twsmedia.co.uk/2020/05/09/atomic-trains/ https://twsmedia.co.uk/2020/05/09/atomic-trains/
        worik 4y ago
        Sense prevailed, and we do not have civilian mobile nuclear reactors. The military are mad. Mad and bad. It is in the job description. We would all be better off if none of them (the military) existed
    - jasamer 4y ago
      Afaik what makes fusion hard is maintaining the conditions that allow fusion to occur. Because of this, it’s quite safe - if anything goes wrong, it’ll just stop working.
moffkalast 4y ago
Yeah hydrogen sounds like it could even be safer given that you get a larger buoyancy buffer to fight downdrafts? It's a real public misconception that it just explodes from all those oxyhydrogen experiments at chemistry class, but pure hydrogen such as in airships just slowly burns, much like any other fuel we fill our planes with. The main problem is still that you need to contain a large volume, which will inevitably get pushed around by wind more than you can compensate for.
pkulak 4y ago
I wonder if you could use a fuel cell to get power from the hydrogen you'd otherwise vent.

BeefySwain 4y ago

You may have overlooked the part where filling the quantity of airships that would (theoretically) be used would represent over half of the KNOWN quantity exploitable on earth, and would take decades to produce at current production rates. Also, they would need topped up over time. Compared to hydrogen, which is cheap, available, and renewable.

credit_guy 4y ago
> KNOWN quantity exploitable on earth It's great that you emphasized "known". Knowledge is not a static thing. Also what's economically exploitable is a variable thing. Currently, the US produces 40% of the world's helium, despite producing only 25% of the world's natural gas. Is it because the US has drawn a lucky lottery ticket for helium? That's very unlikely. Helium is being produced continuously inside Earth as the alpha particles generated during the radioactive decay of some elements (mainly Uranium and Thorium, but Radon too). It seeps upward, and it generally escapes in the atmosphere, but some of it gets trapped in the same geological formations that trap natural gas. In most places people don't bother to see how much helium there is in natural gas. They just sell the gas and take the money. Separating helium can increase the profitability a bit, but it depends on how cheaply you can do the separation. It's very likely that the US has better technology than the rest of the world, and because of that it separates more helium for the same quantity of natural gas. As the technology will spread out, more helium will become recoverable. Also, it may come as a tautology, but more helium is economically recoverable if its price goes up.

mikepurvis 4y ago

As a noble gas, helium can't be synthesized, so its cost is because of its scarcity— and because it's a small molecule (like hydrogen), you inevitably lose some and require continuous top-ups. None of this sounds like it would be realistic at scale, no matter the amount of money in play.

kortilla 4y ago

The FAA approved modifications to piston engines to use unleaded avgas. Jet fuel doesn’t have lead. Also, this isn’t about the FAA just being slow for no reason. Switching from leaded to unleaded without the engine modifications was not safe for the piston aircraft that need it. https://en.wikipedia.org/wiki/Jet_fuel https://en.wikipedia.org/wiki/Jet_fuel https://en.wikipedia.org/wiki/Avgas https://en.wikipedia.org/wiki/Avgas

coryrc 4y ago
It's not safe for us to be breathing. But that doesn't matter to cheapskate rich private plane owners or their regulatory-captured FAA.
- LarryMullins 4y ago
  The really rich private plane owners all have planes that burn jet fuel, which is always unleaded. The piston planes are generally owned by "doctor rich" upper-middle class people, who have political influence to be sure but they're hardly the billionaires that might be known by name to politicians. I think it's more likely that the FAA protects general aviation because general aviation is part of the professional pilot training pipeline.
  - coryrc 4y ago
    [flagged]
    - LarryMullins 4y ago
      > Ah, if you're only "doctor rich" then it's okay to poison children! That's not what I said and you know it. > GA is responsible for 50% of lead emissions! Little lead is emitted at all these days, because leaded gasoline was banned in almost all circumstances. So you're talking about 50% of "not much". I'd be happy to see it banned completely since there are now viable alternatives, but I think you're going a little bit too hard with this class war narrative.
  - 4y ago

TylerE 4y ago

Lift gas is a consumable. You have to vent it to descend in many cases, and that’s ignoring the inevitable leaks and diffusion.

worik 4y ago
> Lift gas is a consumable. You have to vent it to descend in many cases, and that’s ignoring the inevitable leaks and diffusion Helium blimps compression the gas to lower buoyancy

kurthr 4y ago

So, if filling your gas tank cost 8% of the price of your car... you'ld think nothing of it? Lift gas leaks (esp He) and gets vented. So this seems odd to me. It's kinda like buying your car again every few months to a year or paying $250/gal to fill up. Now 80x lower at 0.1% of the car price you're in the regime where it's negligible like an EV.

LarryMullins 4y ago
> Lift gas leaks (esp He) Hydrogen more than helium, I believe.
- kurthr 4y ago
  Each Hydrogen molecule is more reactive, but actually a larger molecule (less leaky) because there are two (it's diatomic H2 rather than monoatomic He). Now it does get complicated, because the simple atomic radii aren't sufficient when you start bouncing around and leaking through other materials, but suffice it to say that He is still smaller once you look at the Vander Walls attraction and everything. It may only be 10% smaller, but that leads to at least a 20% lower leak rate. https://bbblimp.com/2021/09/17/helium-vs-hydrogen-atom-size/ https://bbblimp.com/2021/09/17/helium-vs-hydrogen-atom-size/

dwighttk 4y ago

Author mentioned a market for 25K of these airships, which is like half the helium on earth the first time you fill them up. $8M will go up once you start building

dspillett 4y ago

> Helium would do just fine. Though that creates another problem: there is a shortage of Helium developing that is starting to cause concerts in a few places (like medical imaging, which it is used as a coolant for devices like MRI scanners). That $8E6 might grow significantly not long after the first airships roll off the production line, and it'll raise for other users significantly too as available supply becomes more contested. > There's actually no need for hydrogen. The Hindenburg was originally designed with Helium in mind, but because of a US export ban (at the time Helium was in even shorter supply, and most of it was being produced from resources in the US) forced a redesign. Unless new practical+affordable sources are found, the same sort of design limitations could strike again.