I know it has its problems too, but Hydrogen- recovered from seawater by electrolysis powered by wind turbines standing in the same seawater, seems the obvious way to go.
The Hydrogen and Oxygen could be stored in floatable tanks at each wind turbine, and towed ashore to be used.
In use, it only gives off water- I think it must be the purest renewable fuel.
If we could 'crack' the technical problems involved in storing the stuff, transporting it, and then using it, it might be a really 'green' replacement fuel.
Have a look at Lockheeds' SUNTAN aircraft to see both the problems and practicalities of such aircraft, and for a hint at how H powered jet engines might evolve.
Putting batteries on aircraft is pointless- it's just a way of storing some electricity, whose manufacture probably involved burning coal....