OTOH, hydrogen stored in tanks is cheap to make, renewable, and the tanks never wear out, etc etc etc...

As mentioned above, tanks do wear out - and hydrogen has an additional problem with being stored in them, because it causes hydrogen embrittlement of common tank materials (steel, aluminum etc.) You can coat them, of course, but that presents additional problems.
The plants I work at have neutron flux detectors that slowly turn to gold.
Context is important. Battery-powered EVs are plenty useful given the weight / capacity / range. Same is not true when it comes to flying machines - they're constrained by weight, use more energy, so current battery tech isn't practical for their use. Electrical drivetrains have obvious benefits though, including in flying machines. So currently the only solution that comes to mind is chemical fuel consumed to generate electricity. What fuel, and how consumed is up to you. Hydrogen, methane, propane can be produced using electricity and be carbon neutral.billvon wrote: ↑Jan 25 2019 4:43pmRight. But that's like saying I have an awesome method to create gold out of almost nothing! I'll be a millionaire, right? To create a gram of gold, I just start with three grams of diamonds and . . .
The problem with using electricity to create hydrogen from water is that it uses electricity. And you'd be a lot better off using that electricity to just charge that EV in the first place. Converting it to hydrogen, storing it, transporting it, compressing it and then using it to power a fuel cell means you get about 1/3 of the energy you put in to making it.
Or, like me, they have a look and think, "yeah, whatever".TheBeastie wrote: ↑Feb 19 2019 2:37amThis video has a tiny amount of views for how cool it is, I think there are just too many arseholes out there that never click on the Like button on good videos.
It seems like 650W would have many practical applications. Any idea on the cost ? Also do they have a way to produce / store hydrogen, or the expectation is you'd take those cylinders elsewhere for filling ?
I would imagine you could refill the H2 tank where they refill fuel cell cars.Maximum continuous power 800W
Maximum peak power 1400W
Output voltage 19.6V to 25.2V
Fuel Cell Power Module Dimensions 196 × 100 × 140mm
Mass 930g
Hydrogen Regulator Mass 250g
Maximum regulator (cylinder) pressure 300 Bar/4350 PSI
Output pressure 0.5 Bar ± 0.25 Bar/7 PSI ± 3 PSI
PRV set pressure 2 Bar/29 PSI
Burst disc set pressure 450 Bar/6500 PSI
Maximum cylinder mass 10kg
This is relevantAmpEater wrote: ↑Oct 05 2010 7:48am
Edit - I assumed you were talking human-size quadcopters. RC scale has been done 1000 times by now, even open source projects with hardware available. That doesn't keep me from wanting one, of course. I have a thermal camera that would be awesome to get airborne, but is outside the payload of most smaller quads.
didn't that frenchman just fly across the English channel with a backpack battery?TheBeastie wrote: ↑Jan 08 2020 1:16amHyundai S-A1 Air Taxi.
Hyundai have a fair amount of fuel-cell EVs, so I wont be surprised that the finished product of their Air Taxi will be fuel-cell based as well.
If there was any group of people who should dubious of a miracle battery just around the corner its long-time ES forum dwellers viewtopic.php?f=14&t=57256
https://www.youtube.com/watch?v=L6K7GAG1Aas
No !
A French inventor has crossed the English Channel on a jet-powered hoverboard.
Franky Zapata's hoverboard is powered by kerosene which he carries in a backpack.
He took off from Sangatte near Calais and reached Dover in just over 20 minutes – but he had to stop for fuel.
TheBeastie wrote: ↑Mar 22 2020 11:47pmIn China, its routine to remove debris from powerlines using flamethrower quadcopters