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style="FONT-FAMILY: 'Times New Roman','serif'; FONT-SIZE: 14pt; mso-fareast-font-family: 'Times New Roman'">Gary<?xml:namespace
prefix = o ns = "urn:schemas-microsoft-com:office:office"
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style="FONT-FAMILY: 'Times New Roman','serif'; FONT-SIZE: 14pt; mso-fareast-font-family: 'Times New Roman'"> <o:p></o:p></SPAN></P>
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style="FONT-FAMILY: 'Times New Roman','serif'; FONT-SIZE: 14pt; mso-fareast-font-family: 'Times New Roman'">This
would be very helpful. I am sure this question comes up all the
time. Coincidentally, I was showing my client your web site and that
particular installation in our discussion. <o:p></o:p></SPAN></P>
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style="FONT-FAMILY: 'Times New Roman','serif'; FONT-SIZE: 14pt; mso-fareast-font-family: 'Times New Roman'"> <o:p></o:p></SPAN></P>
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style="FONT-FAMILY: 'Times New Roman','serif'; FONT-SIZE: 14pt; mso-fareast-font-family: 'Times New Roman'">Since
sun's rays are parallel, I assume the shadow created on a clear day is
the same as the thickness of the wire. <o:p></o:p></SPAN></P>
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style="FONT-FAMILY: 'Times New Roman','serif'; FONT-SIZE: 14pt; mso-fareast-font-family: 'Times New Roman'"> <o:p></o:p></SPAN></P>
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style="FONT-FAMILY: 'Times New Roman','serif'; FONT-SIZE: 14pt; mso-fareast-font-family: 'Times New Roman'">Eli
<o:p></o:p></SPAN></P></FONT>----- Original Message ----- </DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px">
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=gdreysa@gmail.com href="mailto:gdreysa@gmail.com">gdreysa</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=greenbuilding@lists.bioenergylists.org
href="mailto:greenbuilding@lists.bioenergylists.org">Green Building</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, April 06, 2011 9:49
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [Greenbuilding] Electrical
line shading of solar PV modules</DIV>
<DIV><BR></DIV>Hi Eli,<BR>I'd agree with Keith that some caution is in order
here.<BR><BR>This is a picture of my Enphase PV array with some modest
shading:<BR><A class=moz-txt-link-freetext
href="http://www.builditsolar.com/Projects/PV/EnphasePV/Shading.htm">http://www.builditsolar.com/Projects/PV/EnphasePV/Shading.htm</A><BR><BR>You
can see from the real time output plot that even the panel with just a line
across it is very much effected.<BR>The shadow is wider than a power line
would cast, and maybe the effect would diminish as the shadow gets narrower,
but I'd be careful.<BR><BR>If I think about it later today and the weather
cooperates, I'll set up narrower shadow and let you know how that comes
out.<BR><BR>The micro inverters are good in that a shadow across one module
only effects the output of that one module and not the whole string, but a
wire shadow that goes across several modules could still have a serious
effect.<BR><BR>Gary<BR><BR><BR>On 12:59 PM, Keith Winston wrote:
<BLOCKQUOTE cite=mid:%3CBANLkTikWHTbcWvMu9ZoG2i53g00zenTYfQ@mail.gmail.com%3E
type="cite">I'm not quite sure what you mean by "smaller than the sun's
disc"... larger power lines can cast distinct shadows. If those align with
an axis of the modules, then they may shade an entire row of cells in a
module, overcoming the ability of the bypass diodes to "bypass" the shaded
cells (most modules are, I believe, still bypassed on a cell-by-cell basis,
and are wired in series along one of their axis). So I'll stand by my
earlier comment that a power line could very well create significant
shading. But I agree with the microinverter
suggestion.<BR><BR>Keith<BR><BR><BR>
<DIV class=gmail_quote>On Mon, Apr 4, 2011 at 11:22 AM, Gordon Howell --
Howell Mayhew Engineering <SPAN dir=ltr><<A href="mailto:ghowell@hme.ca"
moz-do-not-send="true">ghowell@hme.ca</A>></SPAN> wrote:<BR>
<BLOCKQUOTE
style="BORDER-LEFT: rgb(204,204,204) 1px solid; MARGIN: 0pt 0pt 0pt 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>Thanks for your question Eli:<BR><BR>It doesn't appear
that the electrical lines would be a significant issue. They are
likely smaller than the sun's disc.<BR><BR>If you use Enphase
module-inverters (one inverter for each PV module) then any shaded module
wouldn't affect the PV array's performance, because each PV string is a PV
module.<BR><BR>To clarify: the industry term that is an
internationally-recognised standard for PV modules is "module", not
collector, not panel. See attached file for pictoral
description.<BR></BLOCKQUOTE></DIV><BR></BLOCKQUOTE><BR>
<P>
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