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> things that can't be easily electrified, like flying craft Funfact about airplanes: they can pretty easily be converted to run on liquid hydrogen. There was

> things that can't be easily electrified, like flying craft Funfact about airplanes: they can pretty easily be converted to run on liquid hydrogen. There was a big Airbus-led research project on this some years back. IIRC they found overall efficiency (when accounting for larger fuel volume etc. etc.) was ~4% lower than normal aircraft. Not to mention that Tupolev actually built and flew a full-scale proof of concept liquid H2 airliner in the late 80's, the TU-155; sadly yet another cool project that died with the Soviet Union.

ZeroGravitas 10y ago
That is cool, though currently there's no low carbon source of Hydrogen. Possibly over time excess wind an solar power can be used to generate liquid fuels.
- semi-extrinsic 10y ago
  There's steam methane reforming from natural gas; it converts methane to CO2 and H2, and you separate those. This is already a large scale commercial process (e.g. used for hardening fat in food or upgrading petroleum to fuel), giving tens of millions of tonnes per year, and recent plants even include CO2 capture and storage, making it a low carbon source.
mrbabbage 10y ago
What about the fuel tanks that would be required for a hypothetical hydrogen aircraft? Unlike kerosene, hydrogen is very light, but the high-pressure tank to contain the hydrogen is quite heavy. Plus, given hydrogen's very low volumetric density, I imagine you'd have to sacrifice a lot of the cargo volume of the aircraft to fit the H2 fuel tank.
- semi-extrinsic 10y ago
  Liquid hydrogen is the key. It's frickin' cold, as in liquid nitrogen is positively tropical in comparison, but the density is high enough that you just need slightly larger wing volume for tanks. Vacuum based insulation, which is what they use, is pretty light. As I said, Airbus did a large R&D project on this and they concluded it's technically and economically feasible for passenger jets. I'm taking their word for it, seeing as they build airplanes for a living.

ZeroGravitas 10y ago

That is cool, though currently there's no low carbon source of Hydrogen. Possibly over time excess wind an solar power can be used to generate liquid fuels.

semi-extrinsic 10y ago
There's steam methane reforming from natural gas; it converts methane to CO2 and H2, and you separate those. This is already a large scale commercial process (e.g. used for hardening fat in food or upgrading petroleum to fuel), giving tens of millions of tonnes per year, and recent plants even include CO2 capture and storage, making it a low carbon source.

mrbabbage 10y ago

What about the fuel tanks that would be required for a hypothetical hydrogen aircraft? Unlike kerosene, hydrogen is very light, but the high-pressure tank to contain the hydrogen is quite heavy. Plus, given hydrogen's very low volumetric density, I imagine you'd have to sacrifice a lot of the cargo volume of the aircraft to fit the H2 fuel tank.

semi-extrinsic 10y ago
Liquid hydrogen is the key. It's frickin' cold, as in liquid nitrogen is positively tropical in comparison, but the density is high enough that you just need slightly larger wing volume for tanks. Vacuum based insulation, which is what they use, is pretty light. As I said, Airbus did a large R&D project on this and they concluded it's technically and economically feasible for passenger jets. I'm taking their word for it, seeing as they build airplanes for a living.