On Apr 7, 11:33*am, wrote:
On Wed, 7 Apr 2010 10:11:01 -0500, "HeyBub"
wrote:





RBM wrote:

A 6KW system for a home costs about $48K. *This means that it is
totally unviable compared to other electricity generation options.
The only way it becomes viable is for the govt to hand out more money
to get you to install one. * After the gov pays for around half of the
cost, then it can make economic sense for the homeowner. *For the
taxpayers, it's a loser.

In general, people aren't stupid. If solar energy was cost effective,
we'd all be tripping over each other to get it.

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
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.

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.

That is true. Something has to be wrong with the math, because you
can indeed buy a sytem in the 6KW range and put it on an average house
roof. It doesn't even cover anywhere near the whole roof, maybe 40%
or so I'd say. 6KW is an order of magnitude more than HB's claimed
1/2 KW.




Also take into account that people who do this, are likely very
interested in the subject of alternative energy, and may have taken
other measures to both conserve and produce power. Solar works quite
well for heating water in many places. Another really impressive
technology that DOES have a reasonably good ROI despite high initial
cost, is geo-thermal.

Photo-voltaic's don't have to be a complete solution in order to be a
worthwhile proposition. What's the ROI on your car? Is it at least the
most cost efficient car you could possibly own? Is it as cheap as
taking mass transit? If not, then I guess using a car for
transportation isn't economically feasible.- Hide quoted text -

- Show quoted text -

The analogy here would be paying $50K for a car that has the same
performance, size, and features as a toyota corolla. There are some
applications where it is cost effective to use solar electric because
there is no grid. But what we're talking about here is the 95%
installed in populated areas with the rest of the taxpayers and future
taxpayers getting stuck with paying the extra $25K bill.