friendica (DFRN) - Link to source
in reply to Clara Listensprechen {in stickershock}

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Sarah Brown

@Clara Listensprechen {in stickershock} that’s why it’s maybe got future in aviation where the weight of batteries is their Achilles’ heel.

But if you aren’t flying, then batteries are superior to hydrogen in every way.

Particularly when you start asking awkward questions like, “where did this hydrogen come from?”

@Clara Listensprechen {in stickershock}
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friendica (DFRN) - Link to source

Sarah Brown

@Alex Holst

reshared this

in reply to Clara Listensprechen {in stickershock}

friendica (DFRN) - Link to source

Sarah Brown

@Clara Listensprechen {in stickershock} It's used in deep space rocketry because it's a storable. You can coast for years and then when you need to light your engines, it will still be there.

"Ignition" by John Clark is a useful read on this.

Don't use it on Earth. It's repulsive stuff.

@Clara Listensprechen {in stickershock}
in reply to Sarah Brown

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Katie Fenn

I found this episode of Real Engineering to be pretty inspiring.

Rethinking the air liner using the latest composite materials and advances in aeronautics could transform the internal volume for hydrogen too.

I only wish we had the Boeing that designed the 777, and not the mess that designed the 737 MAX.

youtu.be/59A8-rKRs-0?si=Yuq_r1…

The Plane That Will Change Travel Forever

Sign up to Nebula here: https://go.nebula.tv/realengineeringGet a free month of Nebula with any Real Engineering merch: https://store.nebula.app/collections/...
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in reply to Sarah Brown

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TeflonTrout

TANSTAAFL is a real bitch!

About aviation though: Hydrogen is a shit fuel source for flight for all the reasons it blows everywhere else- especially energy density by volume and weight.

Free space in aircraft is actually incredibly limited, and hydrogen containers are both fuck-off heavy and very constrained in shape. Wing fuel tanks work fine for liquids, but pressure vessels won't fit well between the rigid structures of wings and fuselages.

1/2

in reply to TeflonTrout

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TeflonTrout

You are 100% correct about the issue of dead battery weight, hydrogen tanks have the same problem to a lesser extent, but lack the flexibility batteries have in form factor-you can wedge those bastards in all sorts of convenient places.

As for gliding? Well, most powered aircraft, particularly all jets that I know of, are *terrible* gliders. The aerodynamic rules that make them efficient at high speed also dictate that they float like rocks, so that's not a major consideration. 2/2

in reply to TeflonTrout

friendica (DFRN) - Link to source

Sarah Brown

@TeflonTrout the gliding thing was me being a bit flippant. It’s notable, however, that the safe landing weight of many jetliners is lower than the safe takeoff weight and whereas a plane that’s been aloft 10 hours on kerosene weighs a lot less than when it took off, one that uses batteries weighs exactly the same and has to cope with being just as heavy on landing.
@TeflonTrout
in reply to Sarah Brown

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Jono Ferguson

@kincaid

look, it was late and I did say I didn't put any thought into it.

I was thinking of the ass end of Australia, but you are, rather cruelly using my own argument against me that electrons are easier to move than explody gas

I'll go back to my previous position of "I'm open to ideas, but cant' think of any" and this time not offer half ass, clearly not thought through ones 😀

@Kincaid
in reply to Sarah Brown

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Ed Davies

99% agree with you - hydrogen for any consumer application is stupid - electricity (via batteries were required) will always make more efficient use assuming the bulk of our energy is coming from renewable electricity in some form or other.

No opinion one way or the other on hydrogen in aviation. Maybe alcohol or ammonia? Dunno.

Hydrogen for grid-scale semi-interseasonal energy storage does seem to make some sense to me, though. L²/L³ is on your side if you're storing enough of the stuff. OK, the round-trip efficiency isn't great but I don't really see any other way of storing multiple TWh over weeks or months.

The Dutch government seems to have big plans in that direction. They must make at least a bit of sense, even if they're over-affected by the proximity of Shell or whoever.

A reminder for me to re-read Chris Goodall's The Switch, I think.

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Sarah Brown

@argv minus one Ok, so when referring to hydrogen as a fuel, I’m talking about burning it.

Fusion is a different beast, and nearly all hydrogen on the planet is useless for it because any feasible design we can build or envisage uses deuterium and tritium. The former it extracts from seawater. The latter it breeds by bombarding lithium with neutrons.

Anyway, different issue. I do happen to think that trying to build fusion reactors is largely pointless too, but for entirely different reasons: the economics will never compete with a shitlaod of solar panels and a big-ass battery.

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spmatich vk3spm

@argv_minus_one the kind of hydrogen used for nuclear fission is tritium and deuterium, heavy isotopes, which are byproducts of nuclear fission power (at present). Fusion Power stations, when they are up and running in 30y time, will only need tiny amounts. They will likely be able to breed their own fuel because fusion produces a lot of neutrons (which aren’t radioactive in the way the byproducts of uranium fission are). The neutrons can be used to make heavy water, which when split gives heavy hydrogen. At least that was the plan 30y ago when I studied plasma physics.
in reply to Sarah Brown

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Matthew Malthouse

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Even some of the high temperature industries that 5 years ago I was guessing would want hydrogen have tuned to electricity. There have been electric furnaces for steel recycling for years and recently smelting furnaces have gone into production.

Michael Liebreich's hydrogen ladder makes a nice graphic and even that keeps shifting (away from widespread hydrogen use) and is now on version 5.

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Sarah Brown

@argv minus one That upper limit is orders of magnitude more than humankind's entire energy use of all forms put together.

We don't need fusion power on earth, and probably never will, and of the people experimenting with it, the only ones making significant process are just using as a cover for thermonuclear weapons research (National Ignition Facility).

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friendica (DFRN) - Link to source

Sarah Brown

@argv minus one I mean, the following text literally appears verbatim on their website. It's not like they're trying to hide it.

Because it is the only facility that can create the conditions that are relevant to understanding the operation of modern nuclear weapons, NIF is a crucial element of the National Nuclear Security Administration’s science-based Stockpile Stewardship Program.

NIF can repeatedly simulate those conditions inside the Target Chamber’s controlled environment, giving dedicated teams of scientists and researchers the ability to reconstitute and improve upon the capabilities of underground testing.

NIF’s high energy density and inertial confinement fusion experiments, coupled with the increasingly sophisticated simulations available from some of the world’s most powerful supercomputers, increase our understanding of weapon physics, including the properties and survivability of weapons-relevant materials.

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friendica (DFRN) - Link to source

Sarah Brown

@argv minus one BTW, the Space Shuttle and its stupid obscenely eye waveringly expensive bastard child, the alleged "space launch system" was/is also, in a very large part, nuclear weapons programmes. There's a reason that government "space" programmes use solid rocket boosters and commercial space programmes don't: it gives their ICBM engineers something to do.
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