As a former hang glider pilot I've enjoyed the purity of un-powered flight. Because of this I have hoped over the years for powered flight from something other than noisy and vibrating internal combustion engines (ICE).
Since flight for me is strictly for enjoyment, speed that requires lots of power isn't necessary. I believe that advances in battery technology, thin film solar efficiency, and composites in airframe design are all coming together to allow solar electric airplanes.
Here are a couple of examples...
http://www.aircraft-certification.de...one-solar.html
http://www.aeac.aero/
Anyone else thinking along these lines?
A 2 seat trainer that runs $5 per hour vs $75 just might jump start a resurgence in flight schools. Plus like I said, quiet and no vibration is to me very appealing. I don't know how much longer the refineries will still produce 100LL, in Europe it is hard to find and $25 gallon when found.