[at-l] Home Solar Power (Non-Hiking)

[Bob Cummings <ellen@clinic.net> (Bob C.)]

"... I wonder if a mirror system focused on a more densely constructed silicon
cell would jump up the  output exponentially on the same surface area?" queries
RnR.

Only a small amount of electricity falls on a square foot of the earth. That's
why mirrors are used to concentrate that energy on a single location and thus
producing enough energy to boil water -- or power a steam turbine.

 To boil a cup of water requires but a few square feet of mirrors. Unfortunately
 to produce useful electricity from a steam turbine requires an enormous array
 of mirrors -- square miles of mirrors, each carefully focused on a single point
 and tracking the sun as it moves across the sky.

 The delicate mechanical systems -- and cleaning systems to keep dust and air
 pollution from degrading the output -- is enormous. Of all the solar
 technologies, mirrors are the least promising, at least that was the message 20
 years ago from most solar engineers. I haven't kept abreast of such
 developments lately.

 Ordinary solar cells that track the movement of the sun seem to hold the best
 promise for producing useful electricity at a reasonable cost, since focusing
 mirrors and related focusing equipment probably would cost as much or more than
 to simply install the solar cells directly.

 In a perfect system it would take a square mile of mirrors to equal a square
 mile of solar cells. Since a perfect system is impossible, it would take more
 than a square mile of focusing mirrors to equal a square mile of solar cells,
 or at least that is my understanding of the science and mechanics involved.

 Weary