[ExI] Trying for a minimum technical comment

[Andrew Mckee]

On Sat, 15 Dec 2012 07:07:46 +1300, Adrian Tymes <atymes at gmail.com> wrote:

> Also: launch some cubesat solar satellites to
> demonstrate, test out, and validate the on-orbit power
> systems.  Of course these are too small to transmit
> useful amounts of power - but perhaps they can
> transmit detectable amounts of power, and thus debug
> ways to keep a beam on target?
>
> Yes, these might not actually be part of the end solar
> satellite.  They might even ultimately be throwaway,
> like scaffolding.  That does not mean they are not
> worth doing, to lay the path from here to there.


Maybe I haven't been lurking around here long enough, but I'm having a hard time understanding why it's necessary to put a large photo-voltaic array in outer space when for far less money we could float a pair of hydrogen filled rafts in the stratosphere over each of the earth's poles.
Not at the same time of course, but with one enjoying 6 months of 24/7 sunlight the other can be moved towards the equator and at least be on a day-night cycle.

Is chasing 100% utilization really worth the expense of putting a PV array in orbit?

What am I missing here?