H2 does not make any sense whatever.
https://www.linkedin.com/pulse/hydrogen-ladder-version-50-mi...
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.
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.
Hydrogen or ammonia have advantages that can be made from water and nitrogen. Ammonia may be good for ships and planes since can be liquid at cold temps. But can’t substitute in cars.
THEN it definitely makes sense.
You don't think there will be seasonal mismatch between renewable generation and electricity demand?
Because if there _is_ a seasonal mismatch, hydrogen will be needed anyway.
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.
That being said, hydrogen is usually the worst option, but I don't think that's true for every scenario.
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.
It can be part of the main propulsion.
Most internal combustion engine cars have a lead acid battery to start it up and run the spark plugs (or preheat the glow plugs if diesel). They don't get called "hybrid" or "battery powered" because the batteries aren't the propulsive power themselves.
This is akin to that: the batteries run the pumps, they're not the propulsive system itself.
Ion drives can be run off battery, but you can't launch with those.
That's about 0.3% of all energy generated by the engines, which is significantly more than what a spark plug does in an ICE.
[1] https://theaeroblog.com/the-rutherford-rocket-engine-the-fir...
This is the closest we have to electric power directly powering the ascent of a rocket from Earth.
Something like a HyperCurie engine (which is also electric pump-fed), could probably lift off from a planetary body like the moon. When they used it in orbit, they actually had to wait for the batteries to charge up from solar panels between each engine burn.
> 0.3%
> the closest we have
I don't understand why you're trying to paint the battery as a significant contribution here.
Like a car battery, although it's neat that they consider it as part of the engineering, it's none of the actual thrust unless it explodes.
It is all semantics anyway.
I'd agree "it's all semantics", but yours are confusing me :P
(And for energy content, like for like is comparing the size of the fuel tank with the capacity of the battery, but cars aren't 90% fuel by weight).
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?