Weather control as a market for space?

Combs, Mike wrote:

>I've sometimes wondered if one could obtain better leverage with
>microwave beams alternately busting up cloud cover and creating it by
>training on lakes/oceans. Changing amounts of insolation might have
>more leverage (and in both directions) than just providing somewhat
>more light. Might be a good side business for SPS.
>
>Regards,
>
>Mike Combs
>
Interesting question. For one thing I do not understand completely the
nature of such a microwave beam. Doesn't it need a receiver?
Furthermore, won't those SPS microwave transmitter be tuned to send
microwaves *not* being absorbed by water vapor, oxygen or nitrogen? So
they can be transmitted to earth on cloudy days too.

Second, redirecting sunlight by mirrors is easy and something like 95%
efficient. Admittedly clouds are white, which means they scatter and
reflect visible light, but how much of it? Even absorbing 90% and
reflecting only 10% of the light could make them blindingly white
(Remember: moon dust is mostly black, but still looks white in the night
from earth). I don't know about IR-absorption, but IIRC satellites use
some IR-channels to see through clouds. Do you have any numbers
indicating that overall efficiency/cost to convert sunlight into
microwaves and then send this energy into clouds is more efficient?

Finally, with all that talk about electro-smog, many people will make
war on that idea. Giving them only more sunlight like they would get
from a vacation sounds more agreeable, I'd say.

By the way, does any one know how difficult it would be to produce
mirrors that do not reflect UV-rays (which can cause skin cancer, even
though it is a perfectly natural form of radiation, and known to be
important to produce vitamins in the skin)?

Talking about SPS, if you go for thermal power generation, those mirror
producing orbital and lunar facilities can be shared between both
projects. Even if you use solar cells, mirrors could be used to put more
light on the solar cells.
So SPS and weather control may turn out to share a lot of development
costs and make each other more economic due to the larger quantities
processed.