[ianburrell]

There are places where the density of hydrogen doesn't matter. One is long-term storage, where can pump hydrogen underground and then burn it when solar and wind are low. Another is steel production where need high heat, and can store it in big tanks on site. Finally, is ships which have plenty of volume. Planes probably can't use hydrogen.

For ships and planes, we may be able to use lower carbon synthetic fuels like ammonia or methanol, and not have to go as far for synthetic fuels.

Pulling carbon dioxide directly out of the atmosphere is really inefficient. There may be cheaper ways to sequester carbon but they won't give you CO2 for making fuels. Hydrogen is definitely more efficient.

[amarant]

Planes can in fact use hydrogen, though I suppose there might be tradeoffs in not aware of

https://en.m.wikipedia.org/wiki/Hydrogen-powered_aircraft

[ianburrell]

The problem with hydrogen powered airplanes is that hydrogen tanks are heavy and use lots of space. It should be possible to make hydrogen powered planes but they would have to be completely redesigned to work, and may lose range and payload. While with liquid fuels, at least the non-cryogenic ones, can use existing designs and maybe even retrofit existing planes.