🚀 go-pugleaf

In <4butck$9dj@schweik.hal.COM> robk@hal.COM (Robert Kleinschmidt)
writes: 
>
>In article <4btc01$iok@ixnews8.ix.netcom.com>,
>John DeFiore  <john_de@ix.netcom.com> wrote:
>
>	[Re "breakeven" time for PV panels ]
>
>>Well, maybe-  But let's count the energy used to mine and refine the
>>materials needed, the transportation cost to the fab, auxiliary cost
of
>>the fab itself (obviously "amortized" over the life of the fab) 
energy
>>to run the fab and get the workers there, packaging costs,
>>transportation cost to the end user, all the energy costs associated
>>with hooking up the system and fabricating an inverter (manufacturing
>>of the parts involved) or power management system, and the energy
cost
>>of running and maintaining the array.  I have seen a calculation that
>>shows these costs being more than the total output of the cell over
>>it's life.  Granted, amorphous cells will do better, and the realism
of
>>that calculation is open to question, but if you are considering the
>>total energy input into the final system, it is not easily
dismissable
>>as bullshit to question the payback.
>
>Only claim I had ever seen for energy payback was something on the
>order of ~10 years for single-crystal down to ~1.? years for
thin-film.
>
>This probably did not include the guy on the production line with the
>large boom-box or the traffic snarl on the interstate that the
delivery
>truck got caught in, but presumably these peripheral costs would yield
>most readily to optimization as production increased. Given a 10-12
>year warranty period and some reasonable life expectancy past that,
>it would seem that it would take some fairly creative accounting to
>show an energy loss.
>
>Barry's original assumption of 20% efficiency sounds mildly
optimistic,
>but figuring 100-120 Watts/M**2, times 4-6 hrs
insolation-multiplier/day,
>times 10-20 years useful life, times storage/conversion efficiencies
of
>70-90%, I think you arrive at a lifetime production value of between
>1 and 4.5 megawatt/hours of electricity per square meter of PV.
(Better
>estimates appreciated).
>
>If you or anyone else have a general recollection of the calculations
>of energy investment that you have seen, I would be extremely
interested
>in both the totals and a breakdown of principal components.
>
>Rob Kleinschmidt

Rob,
  It was 1987 when I saw the calculations- I remember because I was
working for Lockheed at the time, and one of the other engineers in the
new division I just transferred to showed me the report.  Unfortunately
I can't remember any of the details. Assuming 4.5 megawatt hours is the
lifetime output, and $.08/KWh market value for electricity, that puts
the total output dollar value at $360.00 How much does a 1M^2 solar
panel cost?  What percentage of that cost is attributable to energy
cost vs labor, profit, and raw material cost?  All comments welcome- 
Let's get to the bottom of this.
                                          John