Airline meal-sized £700k awarded by UK.gov for green aviation: That's for eco-tech rather than planes, mind More than a dozen projects that might someday provide the infrastructure at airports to sustain zero-emission aviation are on the receiving end of grant money to continue their research. £700k isn't very much in aviation terms – if any private jet fans are reading this, that's the cost of about one-and-a-half roundtrips to …
Absolutely! Every now and again I read about some development, like a new paint or wingtip design, that will save 1-2% in fuel and hence $billions in annual savings. But they’re happy to throw away 10-30% (or whatever it is) just for wireless charging???
I genuinely can’t think of a single advantage of wireless changing for a plane that is parked up for (dis)embarkation.
Same for cars tbh.
Having said all that, in-air wireless charging could be fun :)
'"hydrogen-electric engine in every aircraft" because it's the only viable way to "deliver truly zero-emission aircraft."'
Burning hydrogen creates water vapour, which is an emission. And it's a "major player in climate change" according to NASA.
Of course we must minimise our effects on the planet but the only way we're going to achieve true 'zero emissions' is to wipe ourselves out as a species. And if we continue demanding more and more as we have done for so long, we'll probably achieve that in the not too distant future. The planet, however, will certainly outlast us even if we just go extinct slowly like most other species do in the long term.
When I ran the numbers a while back, water vapor has about 100 times the greenhouse effect of CO2
* CO2 is only about 0.04% of the atmosphere and is relatively stable, where water varies greatly and can be 1% OR MORE
* CO2 has a tiny absorption spectrum for IR radiation within the band of energies corresponding to temperatures found on earth. Water has an OBSERVABLY SIGNIFICANT IR absorption spectrum, and makes a HUGE difference on earth surface temperatures at night.
And so on.
Worrying about CO2 emissions as compared to WATER VAPOR is like picking up pennies and ignoring $100 bills
(then again I wouldn't worry about either - we cannot control water vapor and C02 pales by comarison, drowned out by the chaos that water adds to the normal weather cycles)
besides, the volume of hydrogen and the containers it would need for an aircraft would make it LESS FUEL EFFICIENT (based on cargo weight and humans on board) than using regular hydrocarbon jet fuel. Until we master hydrogen fusion in an aircraft engine, this will CONTINUE to be the case, because of the laws of physics and the properties of materials. If, however, a clever hydrate-based storage method is developed that can make this "no longer true", then I'll be wrong and you can laugh at me. Until then, hydrogen fueled planes are NOT practical.
The problem isn't the mass of the fuel, it's the container volume. Designing container volume of about 4 times (from an online source) the size of equivalent jet fuel tanks that ALSO have cryogenic insulation and some additional things to keep the H2 both liquid AND pressurized, and that's just the beginning.
The Saturn V first stage and Musk's Falcon rockets use Kerosene-like fuel because of physical tank size and atmospheric resistance. If you can make a taller rocket that has no air resistance, like in space, hydrogen makes more sense for mass-to-thrust. But the tanks still have to be 4 times bigger, so you lose something in the materials used to construct the rocket, not to mention the cryogenics.
But, and this is a serious question, I’m not trolling or a schill for big hydrogen;
Emitted CO2 will remain in the atmosphere for years, decades, even centuries?
But won’t water vapour just precipitate in short order? Maybe a matter of days, hours, possibly even minutes if emitted in subzero temps?
It's true that human activity is causing more H2O to enter the atmosphere, but that has nothing to do with emissions from hydrogen engines. Rather, the added CO2 from fossil fuels is causing the atmosphere to heat, and warmer air can hold more H2O, which means H2O from natural evaporation can spend more time in the atmosphere.
Positive feedback loops like that are nasty, because they amplify small effects until they become a problem. There are several such loops in the behavior of the atmosphere, and when you put them all together, it turns out that even a relatively small increase in CO2, like the one we are currently experiencing, can have end up causing horrible problems through indirect effects.
Emitting H2O directly from H2 combustion, OTOH, does not really feed any feedback loop, so it's literally just adding drops to an ocean. It doesn't matter.
But the concern about storage weight is relevant. Personally, I think that in order to make "green" aviation possible, we'll end up using synthetic hydrocarbons. Electric aircraft may work for small planes and short trips, but I don't see it working for airliners any time soon.
Portable fusion is sci-fi.
£700 per roll of wall paper to decorate Boris' flat
£700k for these "green aviation" projects
£900k for painting the Boris Force One vanity project aircraft
https://inews.co.uk/news/boris-johnson-brexit-coronavirus-raf-plane-jet-travel-voyager-zz336-1104200
so Europe and the rest of the mathematically challenged countries have built big hidey holes for small naval attack forces? Great. Probably true on land so the tanks have somewhere to hide if Russia decides time is ripe to complete takeover of say, Germany, thus showing the book "The Third World War" was only off by a few decades ?
Seriously, the energy requirements for takeoff are so a high an energy dense fuel source is needed. Lastly, where does all the energy needed to make green hydrogen come from ? Green nuclear or more unreliable output hidey holes ?
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