[HN Gopher] A hydrogen-powered air taxi flew 523 miles emitting ...
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A hydrogen-powered air taxi flew 523 miles emitting only water
vapor
Author : geox
Score : 51 points
Date : 2024-07-13 23:25 UTC (23 hours ago)
(HTM) web link (www.popsci.com)
(TXT) w3m dump (www.popsci.com)
| akira2501 wrote:
| Liquid Hydrogen is not a lot of fun. Anything with an 700:1
| expansion ratio is a stored energy hazard in and of itself, but
| because it's cryogenic it also means the cumulative daily loses
| in tanks where cooling is not actively maintained will be a
| constant annoyance.
|
| They seem intentionally coy about how the 523 miles where flown,
| seemingly just above Marina, CA. They have requested that flight
| tracking not be publicly shown on flight aware.
| aftbit wrote:
| You might be able to find them on ADS-B Exchange, either live
| or in the historical data sets. They are somewhat famous for
| only using citizen-sourced ADS-B data and refusing all requests
| to delist or hide data (allegedly anyway).
|
| It looks like their tail number is N542B but I'm not sure how
| to translate that to the ICAO hex codes that they use to
| archive their data nor exactly what date and location the
| flight took place. Some more sleuthing would be required.
|
| https://www.adsbexchange.com/products/historical-data/
| kbaker wrote:
| N542BJ is the tail number (not N542B,) flightradar24 has the
| Mode S code listed even though the flight data is locked
| there. https://www.flightradar24.com/data/aircraft/n542bj#
|
| Some test flights around 6/23 - 6/27. Looks like a pretty
| boring way to get 523 miles. They should fly the loops over
| the Indianapolis Speedway instead.
|
| https://globe.adsbexchange.com/?icao=a6df7c&lat=36.689&lon=-.
| ..
|
| https://globe.adsbexchange.com/?icao=a6df7c&lat=36.689&lon=-.
| ..
| antonvs wrote:
| I wonder if the the high-pressure, non-cryogenic hydrogen tanks
| used in some cars and buses would work. That technology seems
| to have solved the major issues, although I suppose aircraft
| crashes could introduce some additional problems.
|
| Toyota has some detail about their system, which is similar to
| systems used by Honda and Hyundai, at: https://www.toyota-
| europe.com/news/2015/hydrogen-is-that-saf...
| GenerocUsername wrote:
| That's great. How horrible was the process of generating the fuel
| to only emit water by the final link in the energy chain?
| akoboldfrying wrote:
| You don't seem to realise that that process happened far away
| from where _we_ are. Maybe even in a different country.
|
| So when you think about it: Did it even really happen at all?
| pauljurczak wrote:
| Greenwashed hydrogen?
| pdonis wrote:
| "Emitting only water vapor"--which is a much _worse_ greenhouse
| gas than CO2.
| XorNot wrote:
| You might want to consider that 70% of the planet is covered
| with water which emits a lot of water vapor per day, everyday.
|
| Water vapour condenses out of the atmosphere in a matter of
| minutes to hours. CO2 in the atmosphere has a half-life of 120
| years.
| tzs wrote:
| Yes and no. Yes, water vapor is more effective at warming than
| CO2, and is responsible for over half of Earth's total
| greenhouse effect.
|
| But humans have very little effect on the amount of water vapor
| in the atmosphere [1]. Emit a ton of CO2 and that CO2 remains
| in the atmosphere for hundreds of years.
|
| Emit a ton of water vapor and it is gone from the atmosphere in
| weeks. The average emitted water vapor molecule only stays for
| two weeks.
|
| So no, as far as emissions go emitting CO2 is much worse than
| emitting water vapor.
|
| [1] https://climate.mit.edu/ask-mit/why-do-we-blame-climate-
| chan...
| Terr_ wrote:
| Don't worry, any excess water vapor quickly falls out of the
| atmosphere.
|
| Literally. _As rain._
| rad_gruchalski wrote:
| We need to ban water as its existence makes water vapour
| possible. Do something.
| al_borland wrote:
| From what I've read, liquid hydrogen isn't a great option due to
| the energy required to create it. Where does that energy come
| from?
| analog31 wrote:
| Commercially viable hydrogen production starts with methane,
| goes through a combination of "steam reforming" followed by
| "shift reaction." So far as I know, liquefaction involves
| essentially mainstream cryogenic refrigeration.
| Loughla wrote:
| And the energy for that comes from where?
| analog31 wrote:
| Probably more methane. As mentioned in the neighboring
| post, hydrogen is an energy storage mechanism, not an
| energy source. It's also a feedstock for some other
| chemical processes.
|
| Unless we can tap into some sort of "too cheap to meter but
| too hard to transport" energy source in the future.
| coryrc wrote:
| I recently learned there are natural hydrogen deposits:
| https://en.wikipedia.org/wiki/Natural_hydrogen
| analog31 wrote:
| This isn't shocking, given that there's hydrogen in the
| atmosphere.
| wrycoder wrote:
| Hydrogen is just a "battery" for energy storage. The ultimate
| goal is to produce "green" hydrogen by cracking water using
| solar energy - either via photovoltaics or developing a way
| through bioengineering photosynthesis.
| JumpCrisscross wrote:
| > _ultimate goal is to produce "green" hydrogen by cracking
| water using solar energy_
|
| It's miraculous how the gas industry succeeded where clean
| coal failed.
|
| There will be no green hydrogen. It's a veneer. That the
| same folks building LNG terminals are pushing hydrogen
| isn't a coincidence. Even if we get a green hydrogen
| economy, there will constantly be an incentive to
| adulterate the supply.
| avmich wrote:
| Can be from solar cells, the cheapest option today.
| wenc wrote:
| Green hydrogen (from renewables) is not the cheapest option
| to my knowledge. In fact it is not yet cost-competitive.
|
| The electrolysis process is not still efficient today (but
| improving) and does not yet have scale, and the cost is
| several times SMR-produced hydrogen.
|
| Most economical hydrogen is produced through SMR or as a
| byproduct.
| avmich wrote:
| That could be true, but the question was
|
| > From what I've read, liquid hydrogen isn't a great option
| due to the energy required to create it. Where does that
| energy come from?
|
| and to get the cheapest energy, not the cheapest hydrogen,
| today one would surely consider solar.
|
| Having said that, hydrogen could be interested as more
| ecology friendly fuel, which may rule out the commercially
| cheapest, but not clean enough, options.
| defrost wrote:
| To produce 640 tonnes of renewable hydrogen per annum takes:
| https://www.energy.gov.au/news-media/news/australias-
| first-l...
|
| Current project status: https://arena.gov.au/projects/yuri-
| renewable-hydrogen-to-amm...
|
| Related (Australian) hydrogen energy projects:
| https://arena.gov.au/projects/?technology=hydrogen
|
| (and a few other largish projects with no government funding)
| condiment wrote:
| This is pretty cool. They built the taxi to do battery operated
| flights, with the longest flight so far was 150 miles at a top
| speed of around 200 mph.
|
| For reference, 500 miles is the distance between San Diego and
| San Francisco. That's a 90 minute flight that would take closer
| to 2 1/2 hours with this air taxi. So I suspect that this
| demonstration is less about any sort of aspiration to replace
| batteries and fossil fuels with hydrogen, and more a
| demonstration of an operationally clean burning fuel.
|
| The criticisms that hydrogen is environmentally expensive are
| valid, but what's interesting is that the operational use of the
| vehicle, whether it's battery or fuel cell, is effectively
| emissions-free. When the operational fuel is clean, emissions
| improvements can be centralized. That's a really big deal.
|
| https://www.jobyaviation.com/news/joby-progresses-next-phase...
| readthenotes1 wrote:
| If it's a taxi service, is there a chance that +90 minutes for
| security and baggage could be avoided to make the door to door
| time more comparable?
| imtringued wrote:
| You still need to make sure that no one except the pilot can
| take over the controls and that nobody is secretly loading up
| the VTOL with bombs in their luggage with the intention to
| crash it into the side of a glass skyscraper.
|
| Then there is the safety of the passengers. If you and the
| pilot are the only ones in the aircraft, there is not much
| risk to yourself, but if the pilot dies, then the aircraft
| must land autonomously. If there is a group of passengers,
| then a terrorist could take the passengers hostage. So you
| still need to check for weapons and explosives.
|
| The only case where you could get rid of security is with a
| fully autonomous aircraft that carries no luggage and only a
| single person.
| vernon99 wrote:
| This is a weird assumption, see my comment above - there
| already exist a bunch of airplanes operating in the US with
| no TSA. Also, what's the point of bombing small airplanes?
| Why not to bomb a bus instead? The impact would be larger.
| chgs wrote:
| It's not too expensive to buy your own small aircraft
| vernon99 wrote:
| This is already the case with a bunch of small plane
| airlines. They are also reasonably priced (compared to
| chartering). I personally love JetSuiteX (JSX) and the
| experience is truly incredible, with just 5 minutes to board
| the plane from entering the hangar. No TSA, no BS. There are
| a few more with similar service, but as far as I know, JSX
| was the one that found the loophole in the regulations that
| allowed them to run their operations this way legally.
| Proliferation of small aircraft cheap to operate will make
| this model ubiquitous.
|
| Edit: typos
| JumpCrisscross wrote:
| > _is there a chance that +90 minutes for security and
| baggage could be avoided to make the door to door time more
| comparable?_
|
| Blade in New York flies through high-security corridors.
| Check-in is like a minute. (Counterpoint: I regularly show up
| to my small-town airport fifteen minutes before boarding is
| scheduled to start, although that precludes being able to
| check a bag.)
|
| That said: you can't easily take out a building with a
| helicopter. That may not be true with a tankful of 700-bar
| hydrogen.
| briandw wrote:
| Cost to produce H2 from water, 50-55 kWh/kg Cost to liquefy H2 is
| 10-13 kWh/kg 1 Kg of H2 stores about 33 kWh of energy. More than
| 50% of the energy is wasted before transport, storage, boil off
| etc are concerned.
|
| H2 does not make any sense whatever.
| akoboldfrying wrote:
| Well, the article actually admits that 95% of hydrogen produced
| in the US is from hydrocarbons, and thus produces lots of CO2.
|
| And if you think about it for a minute: Do CO2 emissions that
| occur miles away from where I'm standing right now really even
| exist?
| remram wrote:
| Just give me an electric train for that distance...
| coryrc wrote:
| It makes better sense than curtailing solar or wind production.
| 50% is better than zero.
|
| That being said, hydrogen is usually the worst option, but I
| don't think that's true for every scenario.
| jfengel wrote:
| If you had all of that H2, what is the additional cost to just
| fix some CO2 into hydrocarbons?
|
| It feels like that would be a much simpler way to get to net
| zero than having to reinvent all of the infrastructure.
|
| So much simpler that I wonder why anyone would keep trying on
| hydrogen. Which makes me darkly suspect that the goal is to
| take our attention off the solution that's already being
| deployed, i.e. wind and solar.
| skoocda wrote:
| Regardless of net efficiency, that still entails collecting
| CO2 at a central facility (where it could have been dealt
| with in other ways, such as injection underground) and
| sprinkling it through the air as you fly over delicate
| ecosystems. I'm sure bankers see both as net zero, but
| condors might have more issues with your simpler workaround.
| JumpCrisscross wrote:
| > _sprinkling it through the air as you fly over delicate
| ecosystems_
|
| I wouldn't be so sure spraying water vapour is innocuous.
| As long as it's atmospheric CO2, the environmental impact
| of synthetic fuels is much less than rebuilding the world's
| air fleet and fuelling infrastructure to accommodate
| hydrogen.
| rasz wrote:
| >1 Kg of H2 stores about 33 kWh of energy
|
| as horrible as Hydrogen is, isnt that still ~two orders of
| magnitude better than li-ion? Pressure vessel will probably
| bring that down to one order of magnitude.
|
| In cars where weight doesnt matter that much Toyota, leader
| when it comes to pushing BS hydrogen, is only able to get
| Hydrogen Yaris to do 10-14 Fuji laps
| https://www.youtube.com/watch?v=DGL5g91KwLA thats 45-60km of
| range on Hydrogen.
| skoocda wrote:
| That gravimetric energy density is about 2 orders of magnitude
| higher than lithium ion batteries.
| audunw wrote:
| The difference in volumetric energy density is not that big
| though, and hydrogen is not as flexible as jet fuel or even
| batteries when it comes to how you can store it in the
| vehicle.
|
| To be fair, high gravimetric density is a fairly large
| advantage for an air plane. But the bad volumetric energy
| density does present some serious challenges.
| dzhiurgis wrote:
| So why it's not used in rockets?
| imtringued wrote:
| It was used in the Space Shuttle and SLS uses the same
| engine as the shuttle.
| ben_w wrote:
| Also nobody launches to orbit using lithium ion batteries
| as main propulsion.
| dzhiurgis wrote:
| How many kg's to orbit/year vs other fuels?
| rich_sasha wrote:
| But according to HN armchair engineers, electricity will be
| free, nay, negatively priced in T+epsilon as exponential
| decrease in solar panel prices actually turns them negative. Or
| maybe even imaginary.
|
| THEN it definitely makes sense.
| ZeroGravitas wrote:
| H2 doesn't make sense for a lot of things it's promoted for
| (see Michael Leibreich's Hydrogen Ladder for detail on this)
| but this is one area where it makes some kind of sense.
|
| https://www.linkedin.com/pulse/hydrogen-ladder-version-50-mi...
| chgs wrote:
| There are times it makes sense - when you have a remote
| location you need power in that is more than batteries can
| provide for example. Say you need 300kW in a farm miles from
| the nearest supply for 3 months.
| dtgriscom wrote:
| Note that they never say what the payload was. Was there just a
| pilot? Was it just remote-controlled? (I'm guessing just the
| pilot, but that's less than useful except as a personal
| transport, not a "taxi".)
| akoboldfrying wrote:
| It's reassuring to know that the CO2 that will be emitted in the
| end-to-end process of getting these planes airborne will be
| occurring somewhere far outside of my immediate vicinity.
| flembat wrote:
| Generation, transmission, storage and local consumption of
| energy, are separate problems. Hydrogen probably makes sense in
| the long term, it can be transported in pipes, can quickly refill
| a local users tank and is not going to create a monstrous waste
| recycling problem.
| rasz wrote:
| >it can be transported in pipes
|
| how long do the pipes last before crumbing? and how long do the
| pumps last? Toyota cant even make a hydrogen car fuel pump last
| more than 7 hours.
| dzhiurgis wrote:
| We're not even using hydrogen, the most dense fuel, in
| rockets. Why would you use anywhere else? Cars, trucks,
| EVTOLS and even planes are getting batteries which are
| superior in most aspects.
| ben_w wrote:
| Apart from the SLS, Ariane 6, Japan's H3 Launch Vehicle,
| the Russian Angara's KVTK stage, the Saturn V 2nd and 3rd
| stages, and several others which do/did all use hydrogen.
| dzhiurgis wrote:
| How many kg's to orbit/year vs other fuels? It's close to
| 0. If hydrogen is too complex for space, don't even dream
| using one for cars and planes.
| ramon156 wrote:
| Electric trains, people
| TedHartDavis wrote:
| This is seriously impressive to me, if indeed as claimed. I'm no
| longer skeptical about the successful application of hydrogen for
| power in vehicles.
|
| Buuut will we ever make it truly make sense for vehicles en
| masse?
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