Dave,
A guy approached me a while back with a scheme to build an electric powered parachute. That would be about the only aircraft that is less efficient than a helicopter and I told him I thought it probably would not work. Most of the effort in electric aircraft is with very efficient glider like aircraft. Even Boeing is building an electric motorglider.
Anyway, this guy proposed to use ultracapacitors.
Do you have any info on ultracapacitors?
The dimming sun caused by particle pollution is apparently slowing the onset of global warming to some degree. Cheer up!
I saw an advertisement for a large SUV that does 0 to 60 in about 5 sec.
Unbelievable. I was shocked. Nobody seems to care.