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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Hi Todd, <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I concur with your conclusion’s as we do mount on poles some as high as 15’ to bottom of modules depending on average winter snow pack, here in the Sierra around Truckee. We do have one client with taller pole mounts but he’s out of the ordinary.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:navy'>Sincerely,<br><br>Chris Worcester<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:navy'>Solar Wind Works<br>NABCEP Certified PV Installer<br>Phone: 530-582-4503<br>Fax: 530-582-4603<br><a href="http://www.solarwindworks.com/"><span style='color:blue'>www.solarwindworks.com</span></a><br><a href="mailto:chris@solarwindworks.com"><span style='color:blue'>chris@solarwindworks.com</span></a><br>"Proven Energy Solutions"</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> re-wrenches-bounces@lists.re-wrenches.org [mailto:re-wrenches-bounces@lists.re-wrenches.org] <b>On Behalf Of </b>toddcory@finestplanet.com<br><b>Sent:</b> Wednesday, April 13, 2011 10:10 AM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> Re: [RE-wrenches] Heavy Duty Modules?<o:p></o:p></span></p></div><p class=MsoNormal><o:p> </o:p></p><p><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'>Hi Doug,<o:p></o:p></span></p><p><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p><p><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'>I had a customer's roof mount system break modules this spring after yet another record Mount Shasta snow event. This one brought 8' in 10 days.<o:p></o:p></span></p><p><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p><p><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'>The situation here was 15 Evergreen 190 watt modules (rated for 80#/sq ft), on a DP&W power rail mount, on a 6/12 pitch, comp roof. Ice dams were not removed so the bottom edge of 5 module's frames were peeled off the glass... without the frame's support, 2 of the module's glass broke. Evergreen did not warranty the damage.<o:p></o:p></span></p><p><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p><p><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'>From Evergreen:<o:p></o:p></span></p><p><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p><p><span style='font-size:11.5pt;font-family:"Calibri","sans-serif";color:#1F497D'>"The observed damage is attributable to weather related effects, not manufacturing or workmanship issues with the panels.</span><span style='font-size:13.5pt;font-family:"Arial","sans-serif"'><o:p></o:p></span></p><p style='margin:0in;margin-bottom:.0001pt;line-height:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>You are correct, we do guarantee our panels for up to 80 pounds / sq. ft. However, that is for a uniform load. The installation manual, page 3 (attached), has the following warning:</span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'><o:p></o:p></span></p><p style='margin:0in;margin-bottom:.0001pt;line-height:12.0pt'><span style='font-size:8.0pt;font-family:"Avenir-Light","serif";color:black'>The maximum permissible loads apply to uniformly distributed</span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'><o:p></o:p></span></p><p style='margin:0in;margin-bottom:.0001pt;line-height:12.0pt'><span style='font-size:8.0pt;font-family:"Avenir-Light","serif";color:black'>wind or snow loading. Care should be taken to avoid mounting</span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'><o:p></o:p></span></p><p style='margin:0in;margin-bottom:.0001pt;line-height:12.0pt'><span style='font-size:8.0pt;font-family:"Avenir-Light","serif";color:black'>panels in areas that are prone to drifting snow, icicle and/or ice dam</span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'><o:p></o:p></span></p><p style='margin:0in;margin-bottom:.0001pt;line-height:12.0pt'><span style='font-size:8.0pt;font-family:"Avenir-Light","serif";color:black'>formation."</span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'><o:p></o:p></span></p><p><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p><p><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'>I have come to the </span><span style='font-size:14.5pt;font-family:"Arial","sans-serif"'>conclusion</span><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'> that the only real way to mount PV modules in heavy snow country is on a pole mount with a steep winter angle and enough ground clearance (<u>minimum</u> 6' from the bottom edge of the array to the ground) to allow the snow to keep sliding off the array all winter. A roof mount might still work, but it would need to be greater than ~8/12 pitch (not so good for summer production) and accessible to manual snow removal in those critical situations like we had here a couple of weeks ago.</span><span style='font-size:13.5pt;font-family:"Arial","sans-serif"'><o:p></o:p></span></p><p><span style='font-size:13.5pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p><p><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'>One of my most difficult challenges is trying to design my installations to mitigate winter snow damage. I realize very few list members have to deal with these kinds of severe conditions, but any feedback on my empirical conclusions would be welcome.</span><span style='font-size:13.5pt;font-family:"Arial","sans-serif"'><o:p></o:p></span></p><p><span style='font-size:13.5pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p><p><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'>Todd</span><span style='font-size:13.5pt;font-family:"Arial","sans-serif"'><o:p></o:p></span></p><p><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p><p><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p><p><span style='font-size:14.0pt;font-family:"Arial","sans-serif"'>On Wednesday, April 13, 2011 8:44am, "Doug Wells" <dwells@thesolarspecialists.com> said:<br><br>> <br>> <br>> Wrenches,<br>> <br>> Can anyone recommend a panel that is built with more strength or<br>> ability to handle greater load.<br>> I am installing on a shallow pitched roof and am concerned about snow<br>> build up in this particular location.<br>> I know you guys out in the Sierra's get a lot more snow than we do.<br>> What modules are up to the challenge?<br>> Are there any new military spec modules like the old MSX 120's?<br>> Any experience or guidance is appreciated.<br>> <br>> Doug Wells<br>> Morrisville, VT 05661<br>> NABCEP Certified PV<br>> Vermont Solar Partner<br>> The Solar Specialists<br>> www.thesolarspecialists.com<br>> 802-498-5856<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>><o:p></o:p></span></p></div></body></html>