keith wrote:
On Apr 7, 10:33 am, wrote:

It's not just "cost effective," it's generally impossible.

The amount of radiant energy falling on the earth is 120 watts/sq
meter. At

1000W/sq meter

the equator. At noon. With no clouds. Adjusting for latitude, 12
hours of darkness, clouds, and time of day, one would average about
1/3 the maximum, or 40 watts/sq meter. An 1800 sq ft house would
capture, then, (assuming 70% efficiency of the solar collector) 560
watts, or about 1/2 kw.

You'd do good at 20% conversion efficiency and 1/3 is optimistic.


You are correct, my memory was somewhat porous.

Actually, adjusting for daylight/darkness, the average is 342W/m^2. After
applying corrections for latitude (1/3) and cloud cover (1/3), you'd end up
pretty close to my original figure of 40 watts per sq meter.


That's enough for one light bulb (non-CFL), and one TV or one
computer. Forget about the fridge.

You can nibble at the margins, but you can't run this country - or
an average house - off of sunbeams, irrespective of the cost.

Yet, people somehow are able to do it, even though you say it can't
be done.

Some have no choice (built off grid) and fools live everywhere.


Right. SOME people (like the Unibomber and Mexican border-crossers) can live
off of sunbeams, but my claim that trying to do so for the AVERAGE house or
business is doomed - quite simply, it cannot be done.