On Fri, 22 May 2009 12:43:55 -0700, Fred J. McCall wrote:

Marvin the Martian wrote:

:On Fri, 22 May 2009 12:30:11 -0400, Len Lekx wrote: :
:
: Correct me if I'm wrong... but doesn't light behave according to
: inverse-square laws...? Since Mars is twice as far away (roughly)
from : the sun as we are, doesn't that mean that solar energy is
one-quarter : the intensity?
:
: Or am I just plain confused? :-) :
:Earth is, of course, 1 AU away.
:Mars is about 1.4-1.6 AU away. Say, 1.5 AU. :
:So, (1 AU)^2 / (1.5 AU)^2 = 1/2.25 = .44 or 44% :
:McCall is about right when he says you get twice the solar energy on
the :Moon as you do Mars. And it is true solar energy will work better
on the :moon than it does on earth. The problem is, you'd have to haul
up all :that solar energy equipment up to the moon, and you have 2 weeks
of :darkness at a time, so you're going to need some really big
batteries if :you're going to build a base there.
:

Nonsense. If your head wasn't so firmly up and locked you'd think of
these things yourself, since they're pretty widely known.

Use thermal solar (not photovoltaic) and store energy during the day in
molten salts and use those for energy during the dark. Very little to
haul other than reflective film and no batteries.

DOH!

Next?

That "battery" either would be so hot as to radiate too quickly over the
lunar night, or not warm enough to provide useful thermodynamic work.

A structure is needed to hold the reflective film in something that
approximates parabolic shape, or the sunlight won't be focused.

This is very far from the "free energy" claimed. So far, the reflector,
the structure, and the "salts" to melt are needed. You also need a way to
covert hot salts into useful energy.