(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