Originally Posted by
Australopithecus
At this stage it is virtue signalling, as already suggested. Since Rex is allergic to advertising, this might be a ploy for free press coverage.
H2 has around 300% more energy/kg, so the delta isn’t that big, and solar will only close the gap. Still not seeing how to build cryo tanks (fuel temp circa -275°)..
H2 would be the most logical alternative if the issue of safe easy storage can be solved. Also the small issue of as soon as one explodes Hindenberg style again it will be a hard sell.