In article Jim Logajan writes:
(Alan) wrote:
Now, if I had the cash, I would be inclined to see if that 3 horsepower
could be fed to a reasonably efficient prop to drive an ultralight
around. It might be difficult to stay ultralight with all the solar
power weight, but it would be fun if it could be made to work.

You are about 28 years too late - it was demonstrated in 1980. Here's a
brief history of solar powered flight:

http://www.nasa.gov/centers/dryden/n...-054-DFRC.html

Yet none of these efforts were funded and built by individuals.
Research projects are nice, but many of those were extreme cases of
extra light aircraft.

I expect that you have never flown one. Neither have I. Many of
these were special case aircraft, similar to the ones for human powered
flight. They weren't exactly something that you haul out, hop in, and
fly off casually.

With increases in efficiency and dropping prices for solar cells, we
may one day be able to fly our own solar aircraft, instead of just
reading about better funded researchers doing it.

Alan