Re: alternative energy

On Sat, 04 Apr 2009 08:53:22 -0700, Islander <nospam@xxxxxxxxxxx>
wrote:

AndyS wrote:

Islander wrote:

A company called First Solar is now advertising manufacturing costs
below $1 per watt. Their business plan calls for bringing this down to
65-70 cents. No one knows for sure how long the panels will last and
the technology is rapidly changing. So far estimates are in the 20 to
25 year range.

At $1,000 per KW, 20 year life and 5 hours sun average per day, that
results in about 3 cents per KWH. The average cost of electricity in
the USA is 11 cents per KWH.

This is starting to be interesting!

Andy writes:

The present cost of solar arrays is around $7 per watt, and has been
that
way for 20 years. Of course , inflation means that $7 20 years ago
is
maybe $3 today or so, so I guess the actual cost per watt versus labor
required to earn that money has improved....

And we haven't begun to figure in an inverter for energy conversion,
which
may cost $500 and have a 10 year life (if we are lucky) so there's
another
$1000.

Plus batteries for energy storage which allows the energy to be stored
during the day and lights to be run at night. Lots of variation
there, but
in general a couple golf cart batteries will do it, and they'll run
about $1000
or so every 5 years.... So there's another $4000 estimated.

Then there's the aiming mechanism to follow the sun to take advantage
of the 5 hours of full sun. Otherwise, we have to divide the output
by
about 4 or 5, since "full sun generation" assumes the plane of the
array is normal to the incidence of sunlight. Maybe another $1000 for
the motor driven aiming mechanism. Otherwise, we'd need an array
4 or 5 times the previous size.

Then, we have to fool with the system regularly for maintenance and
repair, since rain/snow/hail/uvrays/bird poop/mice all tend
to screw things up royally if left alone....

And so forth....You see, the cost of the actual cells themselves is
small
compared to the cost of the infrastructure to use the power, and the
costs of the infrastructure are going UP instead of down.


So, just using the cost of a cheap solar panel, which doesn't exist
now,
and may never exist (I've heard this prediction for the last 25
years),
isn't the total picture.....

*****************************************************************

Taking another approach: Assume you want to generate 36500 kwh
over 20 years (your numbers)

That's 36500/20 or 1825 kwh per year

On the grid at 11 cents per kwh (your numbers), that would cost $201
per year.

A bank CD that pays 5% would need to be $4020 to generate
$201 in interest

Let's assume you COULD build a system this large for $4020.
that includes all the infrastructure , and maintenance, and would
last for 20 years. (Clearly a fantasy, but for the sake of
illustration..)


In this case, at the end of 20 years, you would have zero dollars
and a pile of used junk.

If you put the $4020 in the bank, the power bill would have been
paid by the interest, and at the end of 20 years you would still
have the $4020......... and the wife would not be on your back
about having the pile of junk hauled off....


No, numbers do not make solar attractive in your or my lifetimes.

On the other hand, if you are in a sailboat, or at the bottom of
a deep ravine in the wilderness, a couple hundred for a small
panel to power your radio so you could listen to Rush
Limbaugh each day for 3 hours would be the best solution.

:>))))) Andy in Eureka, Texas




Eureka, where wind chimes are made to sell so that stupid people
can tell if a breeze is blowing.

I think that your numbers are a bit out of date. I can buy solar panels
on the internet today for less than $2/W. The company that I mentioned
claims to be manufacturing them for $1/W and I mentioned that to counter
your claim that it takes more energy to manufacture them than they
produce over their life. That was true at one time, but no longer.

First Solar's manufacturing costs are less than the competition, but
they still sell the panels for $2.50 a watt, and unsold or uninstalled
panels are piling up in warehouses.
(http://www.greentechmedia.com/articles/first-solar-panels-piling-up-5365.html)

$2.50 is just the beginning. There are other issues like land,
installation, high tension power line access, storage during periods
of overcast and darkness, etc. That $2.50 is just a fraction of the
ultimate cost.

In 1975 California brought on-line a nuclear power plant at Rancho
Seco, west of Sacramento. It produced 900MW of electricity. Fourteen
years later, environmentalists succeeded in getting a referendum on
the ballot to shut it down. It passed. Then, those same
environmentalist had a brilliant idea -- convert the Rancho Seco
property to solar power. The power lines connecting it to the grid
were already there, and if you are familiar with California's Central
Valley, there is no shortage of sun. Today, one of the largest
photovoltaic arrays in the world stands on the Rancho Seco site.
However, it produces less that 1/2 of 1% of the power of it's nuclear
predecessor.

Fortunately Californians would never allow the construction of another
nuclear plant or coal fired power plant. But, unfortunately that
policy means we do not produce enough energy to satisfy our needs, so
it has to come from out of state. As a result, 20% of the power
consumed in California is generated in coal fired plants. Some might
see a hypocritical irony in that fact, but we Californians would
prefer to smoke dope or marry a goat, rather than waste our valuable
time thinking about complicated issues like energy.

The best approach to storage is connecting to the power grid. It is
called net metering and works on the principle of supplying power into
the grid (running your meter backwards) during your sunlight hours and
drawing from the grid when you need it. Power companies in 35 states
are now required to provide this option. Rule of thumb, the hardware
needed in addition to the panels roughly doubles the cost. There are
companies that will install these systems today for $5/W.

There is no justification for movable panels in domestic systems. That
makes more sense for commercial concentrator-type systems. The 5 hours
per day already compensates for that. A lot depends on where you live.
Up here in the NW, it is about 3.5 hours per day and down in your area
it is about 6 hours per day.

1,000 watts is much too small to run a household, of course. There is
some economy of scale going to larger systems, about 20% going from a
2KW system to a 10KW system. If I were installing something today (and
I am not), I wouldn't go below 10KW.

At today's prices, I agree that it still does not make economic sense -
about $50K for a 10KW system. At current energy prices, payback time is
25 years. But, we are still early in the learning curve and the price
of the solar arrays which used to be the most expensive part of the
system has come down quite a bit. And, the price of energy is not going
to go down. Estimates are that if we go to nuclear, it will roughly
double energy costs, but this will be competitive with fossil fuels.
Assuming energy prices double, that drops the payback time to 12.5 years.

So, as I said, it is starting to be interesting. I've got a big expanse
of south facing roof, just in case.

A problem I've always had with homeowners installing solar panels on
roof is:

A. There are probably going to be many roof penetrations, which are an
invitation to leakage.
B. When there are leaks, and/or the roof need to be replaced, the
presence of those panels vastly complicates what was already going to
be a costly undertaking.
C. It's expensive, and at today's rates can't be cost justified,
except in rare cases.

Solar panel installations are best left to the pros, in desert areas
which are plentiful in the United States. Nice hobby, though. I am
reminded of a friend of my father who long ago built a cabin in the
Sierras. He needed electricity, but there was none. He had a brilliant
idea. He built a wooden flume and diverted water from a creek a couple
of hundred feet to a generator house in which he installed a water
wheel and generator. God knows what it cost him, but it was a great
idea. There was only one problem -- not enough flow. It never worked.

I don't want to seem anti-solar or anti-wind. I am not, but these
things will (or should) happen when they are economic.
.

Relevant Pages

  • Re: 71% Say Finding New Energy Sources More Important than Conservation
    ... you have to be prepared to get by with a lot less energy. ... experiment with solar panels that connect to the grid. ... it is difficult to justify on a strictly cost ... TAMU had a study where they took cold water from a surface pond with fountain operated in winter and stored it underground using the existing aquafer. ...
    (soc.retirement)
  • Re: [OT] Paging Frank K.
    ... I suppose that's why you don't place them on the sides of the house as well. ... > panels can generate, that much clean energy was put into the grid and meant ... > into the power stations...it's actually a pretty good prospect in money ...
    (alt.lang.asm)
  • Re: Super-heavy lift reusable launcher
    ... yards of Earth, at the cost of 5,700 American lives over a 10 year ... fulfill all our energy requirements. ... based power needs a receiver. ... let terrestrial solar power lead the way. ...
    (sci.space.policy)
  • Re: alternative energy
    ... results in about 3 cents per KWH. ... The present cost of solar arrays is around $7 per watt, ... If you put the $4020 in the bank, the power bill would have been ... I can buy solar panels ...
    (soc.retirement)
  • Re: alternative energy
    ... results in about 3 cents per KWH. ... The present cost of solar arrays is around $7 per watt, ... If you put the $4020 in the bank, the power bill would have been ... I can buy solar panels ...
    (soc.retirement)
Loading