[ExI] Efficiency of wind power.

[Kelly Anderson]

2011/4/8 John Clark <Jonkc at bellsouth.net>:
> Maybe substitutions will be found but they wouldn't be a solution
> to global warming; solar cells are black and only about 20% efficient, so
> 80% of the light that would otherwise be reflected back into space is
> converted directly into heat.

John,

  This is a common misconception. The earth is very good at radiating
excess heat into space. The globe hasn't warmed because of the heat
generated by burning fossil fuels, but rather by the changes to the
atmosphere caused by the change to the composition of gases in the
air. So it is solar energy that heats the earth once the composition
of the atmosphere has changed. Likewise, it will not heat up because
some panels get hot.

  Now there is local heating, such as the well documented fact that
cities are a few degrees warmer than the surrounding country side.
This is hardly a climate issue, but more of a local inconvenience.

  For many centuries, they have made ice in Iran by putting water out
in shallow pans in the desert at night. The heat radiates out of the
water into space, and viola, ice.

  As for the materials required to create solar panels, they are
working on many different alternatives. Some of my favorite are
biological, and require no special equipment. I love what you can do
with algae to use solar power to create flammable gases (I think
mostly methane).

-Kelly