An electric power a/c has flown (batteries), solar panels are used on gliders to charge batteries. I would expect it to take a lot less than 30yrs to get that lot together. Hopefully before the gas goes out.
Many moons ago I seem to remember "Tomorrows World" showing a model a/c using the static electricity within the atmosphere as a wing levelling / "autopilot". How long before we can harness the stuff that thunder storms are made of & pour it into a motor? Fuel duration:- not applicable.
Well at least I can dream.