[ExI] Thoughts on Space based solar power

[ben]

Despite the subject, this post is NOT about space-based solar power.

However...

It occurred to me while on a flight recently, that the main difference 
between the insolation above the atmosphere and at ground level is 
caused not by the clear air, but by the clouds (anybody care to comment 
on that? Am i wildly wrong, or is this close to the truth?).

So, if you can get your PVs above most of the clouds, this will be a LOT 
cheaper than getting them into orbit, and you can catch a lot of 
sunlight, almost anywhere in the world.

I'm thinking of rafts of helium/hydrogen/hot air balloons, with PVs on 
the top surface, or supporting a PV layer, tethered to the ground, 
floating just above the main cloud layer, with lightwight electrical 
cables (maybe with bouyancy balloons attached at intervals) conducting 
the power to the ground.

No death-ray microwave beams needed, no ITAR problems involved.

OK, i know that 'the main cloud layer' is a rather nebulous (pun 
intended) concept, but the raft's altitude could be changed to suit 
conditions.  Even it's attitude could be changed, to maximise the 
surface area presented to the prevailing light.

Am i talking rubbish? Or is this worth thinking about?

Ben Zaiboc