This is an interesting video from 3-4 weeks ago. The Royal Air Force trialling a 100% synthetic fuel in a light aircraft, made with 100% renewable energy.
Clearly it will be a way off yet - the cost of the fuel and the ability to scale up production [which are related of course] mean it's not coming to a fuel pump any time soon. Still, a 100% synthetic drop in replacement for avgas would be good.
Also, with something so bleeding edge, there's bound to be more than a little hype in the video, but the ability to provide the Royal Air Force with 100% synthetic fuel for ALL its aircraft is certainly worth aiming for. Of course if that happens, I'd expect the fuel would be widely available by then. Exciting times!
Anyway, here is the video. Enjoy!