Electric has a great future for aviation. It solves virtually all the problems we have with propulsion whilst delivering more power-to-weight than any other prime mover (much more than turbines).
It's the energy storage that's still the bottleneck, as you know. But it's advancing in leaps and bounds. Already today, weight for weight, you could get 1 hr endurance out out of an electric 172. That's pretty impressive. With a lighter airframe and advances in energy storage, you could see 3hrs pretty soon.
You might want to look at a thread I started a while ago on the subject:
http://www.pprune.org/private-flying...-aircraft.html