<!doctype html public "-//W3C//DTD W3 HTML//EN">
<html><head><style type="text/css"><!--
blockquote, dl, ul, ol, li { padding-top: 0 ; padding-bottom: 0 }
--></style><title>Re: [RE-wrenches] Inter row shading: Portrait V
landscape</title></head><body>
<div>All,</div>
<div><br></div>
<div>Thanks William for this! I love it when someone comes up
with a design parameter I've never thought of. What would be
great is if module manufacturer's would include in their manuals some
quantitative data on how vertical and horizontal shading swaths affect
output.</div>
<div><br></div>
<div>Any data you have would be invaluable as I imagine the rough
ratio would apply to most modules wired in the same way.</div>
<div><br></div>
<div>I've always done my interrow shading calcs assuming any shading
is bad and I think that folks should still hold to this standard.
It really irks me when some big company new to solar puts in a large
ground mount array where they had plenty of room to work with but they
still use the noon at Winter Solstice as their design input for
shading threshold angle. 9 AM- 3PM for a couple of months
surrounding that date and they are throwing their power away for no
good reason.</div>
<div><br></div>
<div>So I just hope that William's revelation doesn't become an excuse
for others to put rows closer in landscape than good design dictates.
I use 5 less than the Winter Solstice noon angle as my shading
threshold angle for most jobs. I encourage folks to consider
sticking to this kind of standard whether landscape or not!</div>
<div><br></div>
<div>Best,</div>
<div><br></div>
<div>Jeff C.</div>
<div>Village Power Design</div>
<div><br></div>
<div><br></div>
<div><br></div>
<div><br></div>
<blockquote type="cite" cite>Friends:<br>
<br>
We field tested the concepts this morning and the answer is "yes"
(inter-row shading in portrait mode: bad -- in landscape mode: less
bad).<br>
<br>
William<br>
<br>
<br>
<br>
At 08:40 PM 4/22/2010, you wrote:<br>
<blockquote type="cite" cite>Friends:<br>
<br>
99% of the time, we install modules in portrait mode. We find
ourselves installing a set in landscape with some short inter-row
spacing, due to roof vents. We are using Solarworld SW230
modules.<br>
<br>
It is my understanding that shading the short edge of this type of
module is much more detrimental to the output than shading a long
edge. This is because of the manner in which the cells within
the module are arranged in series. I understand that one string
is on the bottom half of a module and the other on the top half of a
module in the landscape orientation. In order for the module to
cease power production, you have to shade at least one cell from each
of the two internal strings. Therefore, you need to shade more
than half of a module in the landscape mode before the module before
the output declines drastically.<br>
<br>
Is my understanding here correct? I will be testing this
tomorrow if weather permits.<br>
<br>
Thanks in advance.<br>
<br>
William Miller<br>
<br>
<br>
<u>Please note new e-mail address and domain:<br>
<br>
</u>William Miller<br>
Miller Solar<br>
Voice :805-438-5600<br>
email: william@millersolar.com<br>
http://millersolar.com<br>
License No. C-10-773985<br>
_______________________________________________<br>
List sponsored by Home Power magazine<br>
<br>
List Address: RE-wrenches@lists.re-wrenches.org<br>
<br>
Options & settings:<br>
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org<br
>
<br>
List-Archive:
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org<br>
<br>
List rules & etiquette:<br>
www.re-wrenches.org/etiquette.htm<br>
<br>
Check out participant bios:<br>
www.members.re-wrenches.org<br>
<br>
<br>
No virus found in this incoming message.<br>
Checked by AVG - www.avg.com<br>
Version: 9.0.814 / Virus Database: 271.1.1/2829 - Release Date:
04/22/10 11:31:00<br>
</blockquote>
</blockquote>
<blockquote type="cite" cite><u>Please note new e-mail address and
domain:<br>
<br>
</u>William Miller<br>
Miller Solar<br>
Voice :805-438-5600<br>
email: william@millersolar.com<br>
http://millersolar.com<br>
License No. C-10-773985</blockquote>
<blockquote type="cite" cite><br>
_______________________________________________<br>
List sponsored by Home Power magazine<br>
<br>
List Address: RE-wrenches@lists.re-wrenches.org<br>
<br>
Options & settings:<br>
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org<br
>
<br>
List-Archive:
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org<br>
<br>
List rules & etiquette:<br>
www.re-wrenches.org/etiquette.htm<br>
<br>
Check out participant bios:<br>
www.members.re-wrenches.org</blockquote>
<div><br></div>
<div><br></div>
<x-sigsep><pre>--
</pre></x-sigsep>
<div>~~~~~~~~~~~~~~~~~~~<br>
Jeff Clearwater</div>
<div>Senior Design Engineer</div>
<div>Village Power Design<br>
Solar Design Consultation for the Commercial Sector<br>
http://www.villagepower.com</div>
<div>gosolar@villagepower.com<br>
<br>
Voice: 831-427-2799<br>
Fax: 413-825-0703<br>
245 Dufour St<br>
Santa Cruz, CA 95060<br>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</div>
</body>
</html>