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<DIV><FONT size=2>Joel:</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>I have noticed that the energy predicted by the CSI calculator
is consistently lower than the first year output of our systems, usually by at
least 10% to 20%. This is also true of the PVWatts version we use.</FONT></DIV>
<DIV><FONT size=2>At first we thought that we had done such a great job!
But I believe that the accumulative conservative default values in both
calculators and the expectation for module degradation built in to the source
code is the real answer. If our customers ever have an issue with
understanding lower production, it is usually because they fail
to recognize that daily or monthly production values relate to annual
production expectations on a non-linear basis. Recently El Nino has
dramatically affected generation and as well, our own production
schedule.</FONT></DIV>
<DIV><FONT size=2>Kicked out butts, in fact.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Pat Redgate</FONT></DIV>
<DIV><FONT size=2>Ameco Solar</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>In a message dated 4/25/2010 9:43:09 A.M. Pacific Daylight
Time, joel.davidson@sbcglobal.net writes:</FONT></DIV>
<DIV>
<BLOCKQUOTE style="BORDER-LEFT: blue 2px solid; PADDING-LEFT: 5px; MARGIN-LEFT: 5px"><FONT style="BACKGROUND-COLOR: transparent" color=#000000 size=2 face=Arial>Wrenches,<BR><BR>With the Iceland volcano in the news and winter
over, I thought it would be <BR>a good time ask wrenches convince their
customers that their reduced solar <BR>production was caused by atmospheric
conditions and not their PV system. I'm <BR>not talking about short-term
conditions like a few cloudy days. I mean when <BR>you install a PV system in
October and have to explain in gloomy February <BR>why their PV system is not
performing like you predicted.<BR><BR>Missing the mark can be bad for
business. For example, reduced insolation <BR>caused by the El Chichon Mexico
volcano was reportedly one of the reasons <BR>that the Luz solar power plants
went bankrupt in the 1980s. See
<BR>http://en.wikipedia.org/wiki/Solar_Energy_Generating_Systems and
<BR>http://www.unige.ch/cuepe/html/biblio/pdf/michalsky-ineichen%201993%20-%20mount%20pinatubo%20and%20solar%20power%20plants%20(solar%20today).pdf<BR><BR>Joel
Davidson <BR><BR>_______________________________________________<BR>List
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