Just on this point, but a coast full of windmills in this country could easily power all aviation to, from and in this country, if a way could be found to get the electrical energy into a form that could be effectively and efficiently carried by aircraft.
Very roughly speaking, UK aviation consumes 15 million tonnes of Jet A1 per year. That amount of jet fuel contains the same energy as wind farms (or any other power source) generating an average of 20GW* all day every day. By coincidence that is almost exactly what our wind farms are generating right now from 30GW of capacity (acknowledging there is a bit of a breeze out there now). This calculation does not take into account system / process losses (ie the % of chemical energy in JetA1 that is converted to useful work), nor capacity factors of wind power (ie it‘s not always windy). However both are in the region of 30-40%, and therefore for the purposes of this exercise, roughly balance.
Therefore if we (roughly) doubled the size of wind power generation** it could produce enough electricity to power our aviation sector, if battery planes became a reality.
*I was surprised it was this much energy, so double checked sources and triple checked calculations, and it appears to be right.
** As it happens, current plans are that the amount of wind generation in this country will more than doouble by the end of the decade, with more than two thrds of it already under construction or with planning consent and ’shovel ready’.