a few dozen of km2 according to my napkin calculation. for one minuscule airport.

The proliferation of solar farms is well underway and not abating with or without e-fuels, this just gives greater optionality to the energy they output and helps with intermittency. The land-use footprint of their tech as such is 100,000 gallons of car fuel per year per 'forge', each of which fits on a flatbed truck, plus a slated 5 manufacturing facilities to make the forges. That doesn't seem too bad.

On the land-use of the solar panels themselves, I wonder if at some point in the future it might be possible to beam a directed laser to earth from space-based solar arrays, so the earth-based footprint is reduced.