On Jan 27, 4:03*pm, "HeyBub" wrote:
Chris Friesen wrote:
On 01/27/2010 09:09 AM, HeyBub wrote:

You can't run an Aluminum production facility - that takes Gigawatts
of power - off of sunbeams. Ever.

You underestimate the sun.

Average insolation for the earth is 250W/m^2. *Using arrays of mirrors
to focus heat it would take a reflective area 1kmx4km to generate 1GW
of power.

Heh! Can you imagine what it costs to cover 4 sq km with grass seed, let
alone MIRRORS?

I have run the numbers. Allowing for conversion efficiency (70%), darkness
(12 hours), clouds (20%), and latitude (30°N), it would take a solar
collector the size of the Los Angeles basin (~1200 sq miles) to supply
electricity just for California (~50Gw). The only way to reduce the size of
the solar farm is to move the orbit of the earth closer to the sun.

Now, polish that mirror.

Leaving aside the cost to construct, install, and maintain something
covering 3,000 sq km, the citizens in Los Angles would have to live in
perpetual darkness.

Which, when one thinks on it ....

They don't. That's the point.