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Toyota’s hydrogen-powered Mirai has experienced rapid depreciation

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Re: Toyota’s hydrogen-powered Mirai has experienced rapid depreciation

#381

Post by fuzzfactor »

wisplike wrote: post #320
KennyBlanken wrote: post #295

Earlier quoted context omitted.

Same with nuclear. The most expensive form of electricity generation there is. No grid operator wants to touch it, but the nuclear industry has been very busy lobbying congress and both the current and last administration.

Nuclear is incredibly energy dense, can be stockpiled for a long time and is extremely safe. Yes its expensive but its one those industries any serious nation needs to subsidise for the energy security it offers and the countless high skill jobs it fosters.

Well, no it's never been extremely safe by any stretch of the imagination.

That's just an extreme interpretation of the way it's not as extremely unsafe as it could be.

Plus at the rate it's being addressed by a few enthusiasts, it could be getting remarkably safer, maybe even in one person's lifetime someday.

Developments may be positive but it makes the most sense to be realistic and avoid the completely unfounded hype involved.

Plus when nuclear works best the high-skill jobs resulting have to be as non-countless as possible, that's one of the big factors which might someday allow the economics to be less unfavorable.

Re: Toyota’s hydrogen-powered Mirai has experienced rapid depreciation

#382

Post by closewith »

bjelkeman-again wrote: post #377
sandworm101 wrote: post #362

Earlier quoted context omitted.

Life expectancy. A hydrogen tank can be refilled forever. A battery is normally limited to a few thousand cycles. A truck, or airplane, is expected to be fueled/recharged daily for decades. A car is designed to survive the length of a standard lease. Those running fleets of trucks/aircraft will always care more than car owners about long-term ownership costs.

There is something called hydrogen embrittlement. Where hydrogen causes cracks in metal. https://en.wikipedia.org/wiki/Hydrogen_embrittlement

Yeah, Li-ion batteries already have comparable life cycles to hydrogen tanks 1-2k fills/recharges, _but_ batteries are improving rapidly and tanks are already a mature technology.

Re: Toyota’s hydrogen-powered Mirai has experienced rapid depreciation

#383

Post by closewith »

pfdietz wrote: post #373
throwaway473825 wrote: post #325

Earlier quoted context omitted.

Liquid hydrogen loses 1% of its volume per day due to boil-off. Hydrogen is incredibly difficult to move without huge energy losses.

It would be moved by pipeline as a compressed gas, not as LH2. The US already has > 1000 miles of H2 pipelines.

All between co-located industrial generators and consumers. H2 pipelines are DOA due to the absurd compression costs.

Re: Toyota’s hydrogen-powered Mirai has experienced rapid depreciation

#384

Post by fuzzfactor »

lstodd wrote: post #332
api wrote: post #235

Earlier quoted context omitted.

Biofuel makes more sense for airplanes. No conversion even necessary. You could fuel up a 737 with properly formulated biofuel and fly it now, though a lot of validation would be needed to be generally allowed especially for passenger flights. If we want easier to produce biofuels then LNG aviation makes sense. We are flying LNG rockets already. You could go ahead and design LNG planes now and they’d emit less carbon…

LNG aviation does not make any more sense than H2 aviation. Even LPG does not make any sense since you neither can haul 16 bar fuel tanks, nor can you realistically maintain temperature for 1-2atm pressure. And any leak is not 'oh. look, a kerosene stain on tarmac', it's ready-made fuel-air explosion. On the plus side we would be able to retire airport fire engines because they would never be able to get to a crash b…

You can't get much better than ready-made, for rocketry.

As if LNG is effectively more dense in flight than ordinary LPG, which doesn't need to be cryogenic to handle.

Armchair fuel experts do still provide food for thought though ;)

Re: Toyota’s hydrogen-powered Mirai has experienced rapid depreciation

#385

Post by closewith »

thrownthatway wrote: post #286
MagicMoonlight wrote: post #257

Earlier quoted context omitted.

You can’t make and store bulk hydrogen at home

You can’t. I’m willing to give it a go. I’ve got the excess solar from the rooftop solar panels, the electrical and electronic knowledge, and the gas fitter and metal fabrication experience. I have an oil free air compressor, and anyone can by a helium based cryo-cooler. I have an account with an industrial gas supplier. Just enough knowledge to be dangerous. If Nile Red hasn’t blown his lab up by the time I publish…

No air compressor can compress hydrogen, nowhere near the necessary tip velocity.

Re: Toyota’s hydrogen-powered Mirai has experienced rapid depreciation

#386

Post by Thiez »

wao0uuno wrote: post #369
Manuel_D wrote: post #327

Earlier quoted context omitted.

Is suspect large trucks may eventually move to hydrogen, but smaller passenger vehicles will stay on batteries. The nature of hydrogen containment favors larger capacity, on account of better volume to surface area ratios.

I worked in one of the top 5 logistics companies in the world and I can recall them investing in electric trucks and charging infrastructure. Idea was to have strategically placed overhead lines that could recharge trucks without need for them to stop. Can't recall any mentions of hydrogen.

I have seen at least one stretch of highway in Germany that has overhead power lines for trucks. I think it's a very interesting concept: the big downside of batteries is slow charging (compared to diesel) and limited range. Charging while driving on highways would largely solve these downsides.

Re: Toyota’s hydrogen-powered Mirai has experienced rapid depreciation

#387

Post by fuzzfactor »

ForHackernews wrote: post #88
aunty_helen wrote: post #60

Kinda glad this is the case. When people go out of their way to avoid common sense they should be punished. Hydrogen is such a terrible idea it was never getting off the ground. There seems to be some kind of psychosis around it being the next oil and therefore greedy people want to get in early on. But this blinds them to the basic chemistry and physics.

Why is it such a terrible idea? In theory you can generate it via electrolysis in places with plentiful renewable energy, and then you've got a very high-density, lightweight fuel. On the surface, it seems ideal for things like cars or planes where vehicle weight matters. Batteries are huge and heavy and nowhere near as energy dense as gasoline.

>you've got a very high-density, lightweight fuel.

Correction, a very low density, lightweight fuel.

Burns clean though with no carbon in the exhaust.

But the upstream carbon emissions have not come close to zero when you look at total hydrogen use in the real world so far.

Re: Toyota’s hydrogen-powered Mirai has experienced rapid depreciation

#388

Post by fuzzfactor »

jjtheblunt wrote: post #277
aunty_helen wrote: post #60

Kinda glad this is the case. When people go out of their way to avoid common sense they should be punished. Hydrogen is such a terrible idea it was never getting off the ground. There seems to be some kind of psychosis around it being the next oil and therefore greedy people want to get in early on. But this blinds them to the basic chemistry and physics.

> When people go out of their way to avoid common sense they should be punished. This is the most ridiculous assertion i've seen today. You'd shut down science, for example, and innovation in general.

Really, they shouldn't be punished, they should be rewarded if they can become more sensible.

Positive incentive please :)

That is how EVs got here as soon as they did.

Re: Toyota’s hydrogen-powered Mirai has experienced rapid depreciation

#389

Post by dyauspitr »

GregDavidson wrote: post #186

This technology is completely amazing - for large fleet vehicles like buses, trucks, ferries, etc. Also airplanes! Getting this so compact and refined is a technological miracle. Now put it where it fits!

A huge tank of hydrogen is a bomb. This isn’t like gasoline that takes a lot to ignite.

Re: Toyota’s hydrogen-powered Mirai has experienced rapid depreciation

#390

Post by fuzzfactor »

aunty_helen wrote: post #167
ssl-3 wrote: post #116

Earlier quoted context omitted.

Ignoring some of the other issues: Imagine we have this electrolysis plant, splitting up water to produce the hydrogen we need for an area. That's fine. But it needs fed electricity to keep the process going. Lots of it. It needs more electrical power to split the water than combining it again produces. So it starts off being energy-negative, and it takes serious electricity to make it happen. Our grid isn't necessar…

It’s not even the grid, by the time you’ve done the electrolysis you’d be better off just charging a battery. Also, compressing and cooling a gas takes another huge hit at the efficiency. Electrolysis comes out at atmospheric pressures. Oh and the platinum electrodes you need… I’m also just now visualising a hydrogen pipeline fire… terrible terrible idea.

Also, what pipeline operator is going to want to move hydrogen when almost all other products are more valuable?
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