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how much power does it take to produce a solar panel? - Page 2

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Posted by Erdeemal on May 5, 2009, 1:02 pm
 
Eeyore wrote:

Graham you should update. Now on EBAY you can buy solar *cells* at
a bit less than US$.00 per watt peak. Knowing that a watt peak
produces approximately 1 kWh per year in London (2.5 in sunny Sahara),
on 10 years it will provide you with kWh at US$.10  . I pay my day
kilowatts at US$ 0.25 per kilowatt.

As I wrote two years ago here: "The dreamers are not the one who
think that solar energy will prevail, the dreamers are the one who
think they can stop it."

I too wrote that this will probably lead to a bank collapse :)
(due to all the changes implied).

I am the new Nostradamus :). I will not tell you what I see
for you :)

Erdy

Posted by Russ in San Diego on May 5, 2009, 12:46 am
 
On May 4, 3:01pm, maur...@tpg.com.au (Mauried) wrote:

For conventional, terrestrial applications, OF COURSE that question
has to be asked and answered. Especially in the case of a utility
provider.  It wouldn't make a whole lot of sense to burn enough coal
to produce 10 megawatt-hours in order to produce a device that will
generate only 5 megawatt hours over its lifetime.  For special purpose
applications (e.g., off-grid sites), the question is not terribly
relevant.

As for whether the panels will break even financially -- that's an
orthogonal question.  It's also relevant in certain situations, but
irrelevant in others.  If you're only interested in being "green", the
financial breakeven question may not be terribly important.  Again, if
you're a commercial entity, only interested in providing power for
people to buy, it may be very relevant (even so, it's not necessarily
the primary issue).

I've got a nice PV setup, and I suspect I'll reach power consumption
breakeven eventually (perhaps I already have -- my 4KW system has been
operational for nearly 8 years), but I'm not convinced it will reach
financial breakeven, ever.  And I understood all that before I made my
purchase.

Posted by Ron Rosenfeld on May 5, 2009, 1:59 am
 On Mon, 04 May 2009 11:27:33 +0200, Tomasz Chmielewski


No it is not true.  The energy cost of production is not a straightforward
calculation however.  Today’s PV industry generally recrystallizes any of
several types of “off-grade” silicon from the microelectronics industry,
and estimates for the energy used to purify and crystallize silicon vary
widely.

http://www.nrel.gov/docs/fy04osti/35489.pdf

So they are using waste materials -- do you want to charge for the energy
used to produce the waste?  Then you'd have to give a credit for the energy
saved by not having to dispose of the waste.

There've been a number of published estimates ranging from 120 kWh/m2 for
frameless amorphous silicon (add another 120 for the frame) implying a 1-3
year payback in an average US location, up to 420 kWh/m2 for
multicrystalline and 600 kWh/m2 for single crystal silicon and a payback of
2-4 years.

Knapp and Jester studied an actual manufacturing facility and found that,
for single-crystal-silicon modules, the actual energy payback time is 3.3
years. This includes the energy to make the aluminum frame and the energy
to purify and crystallize the silicon.

(K. Knapp; T.L. Jester, “An Empirical Perspective
on the Energy Payback Time for PV Modules.”
Solar 2000 Conference, Madison, WI, June
16–21, 2000).

--ron

Posted by Martin Riddle on May 10, 2009, 5:44 am
 Interesting I did a rough calculation that came out to 7years, just
using estimated costing from current panel pricing.
If I had used a southern insolation  instead of 3.5hr it would had been
closer to 3 years.

Cheers





Posted by Ron Rosenfeld on May 10, 2009, 3:26 pm
 On Sun, 10 May 2009 01:44:23 -0400, "Martin Riddle"


At least one of the papers used about 5 hrs, as an "average USA insolation
value".
--ron

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