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I agree with Allan that this looks like cracked cells. As long as
the conductors on the top and bottom remain intact, there will be
little if any degradation in the output. But the conductors are
under more stress than normal and with daily thermal cycling they
may break which could leave pieces of the cell isolated.<br>
<pre class="moz-signature" cols="72">--
Kent Osterberg
Blue Mountain Solar, Inc.
<a class="moz-txt-link-abbreviated" href="http://www.bluemountainsolar.com">www.bluemountainsolar.com</a>
</pre>
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On 11/9/2011 3:02 PM, Allan Sindelar wrote:
<blockquote cite="mid:4EBB066A.5050004@positiveenergysolar.com"
type="cite">
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Daryl,<br>
Before offering my opinion, I'll note that it's only that, and I'd
hope to learn from others with more knowledge of PV cell structure
than I have. Given that, it appears to me that the silicon wafers
that make up these cells are extensively cracked. It likely will
have little effect on cell output, as the electrons that are
knocked out of their orbits by the photons of light must only move
through the silicon semiconductor as far as the microgrid of
conducting traces visible on the surface; that is, few if any need
to bridge any of these apparent cracks in order to reach the
conductive traces.<br>
<br>
At my own off-grid home, all of my (BP85-90 W) modules are from
the mid-nineties. Many of the cells on about 10 of the 18 modules
are extensively cracked in similar ways, as they came from an
abandoned (good idea that didn't work out) system from a local
Boys' and Girls' Club. When I bought the dead system (quite
cheaply), 8 out of 18 modules had been shattered by kids using it
as a target for throwing rocks. All of the intact modules have
multiple cracked cells and even chipped cover glass. All continue
to perform after 15 years with only a little more than predictable
degradation.<br>
<br>
But to repeat, I'm interested in others' opinions, as I may be
completely off base here.<br>
Allan<br>
<br>
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<font face="Times New Roman, Times, serif"><b>Allan Sindelar</b></font><br>
<small><a moz-do-not-send="true"
href="mailto:Allan@positiveenergysolar.com"><font
face="Times New Roman, Times, serif" color="#000099"><u>Allan@positiveenergysolar.com</u></font></a></small><font
face="Times New Roman, Times, serif"><br>
<span style="font-size: 10pt;">NABCEP Certified Photovoltaic
Installer<br>
NABCEP Certified Technical Sales Professional<br>
New Mexico EE98J Journeyman Electrician<br>
<b>Positive Energy, Inc.</b><br>
3201 Calle Marie<br>
Santa Fe, New Mexico 87507<br>
<b>505 424-1112</b><br>
<a moz-do-not-send="true"
href="http://www.positiveenergysolar.com/" target="_blank"><u>www.positiveenergysolar.com</u></a><o:p></o:p></span></font>
<p class="MsoNormal" style="margin-right: 722.25pt;"><span
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<br>
On 11/9/2011 2:41 PM, <a moz-do-not-send="true"
class="moz-txt-link-abbreviated"
href="mailto:penobscotsolar@midmaine.com">penobscotsolar@midmaine.com</a>
wrote:
<blockquote
cite="mid:ff80be43ccd855638e7103ee7ebf54ae.squirrel@mail.myottmail.com"
type="cite">
<pre wrap="">Hello all,
We have a customer who has acquired, over the last ten years or so, a
large array with several different makes and models of panels, all
installed by a qualified electrician and the customer. They have done
an excellent job as far as self installed systems go.
He just sent me a picture of one of his Canadian Solar 210's with a
very unusual pattern on it (actually under the glass). The panel is
about three years old and shows no decline in output, but he is
concerned with the very obvious visible pattern. I have never seen
anything like it.I've attached it to this email. Anyone?
Thanks for any suggestions or ideas,
Daryl</pre>
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</blockquote>
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