Check out this article, advocating the use of airships to loft optical
telescopes: http://www.dartmouth.edu/~news/releases/2006/07/14.html

Then ponder this: under what conditions might it make sense to put large
banks of solar panels on such airships, and beam the energy to the
ground?

They're above all clouds and weather, and above 95% of the atmosphere.
The cost would be substantially lower than even a LEO satellite, I
think. Unlike a LEO satellite, it could maintain a stationary ground
position. Unlike a GEO satellite, it could do so even at high latitudes.

Of course, like a LEO satellite (and unlike one in HEO), it would be
eclipsed every day, just like solar panels on the ground. But that
weather issue may still make it interesting. If you have a location
which is frequently overcast, and has high peak power demands during the
day, then such a high-altitude station could provide clean power right
where it's needed.

If it also happens to demonstrate the feasibility of beamed solar power,
and get people wondering how to eliminate that pesky diurnal cycle, then
so much the better.

Any comments?

Best,
- Joe