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</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:black'>I have a new client in ID that has the same product. The 48 volt system has a relay style era charge controller that we will upgrade this summer. He has no issues achieving equalization voltages PV direct without the generator. For a product that had a lot of press in the early days this is only the 2<sup>nd Unisolar</sup> system I have seen since Jan of ’88. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:black'><o:p> </o:p></span></p><div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Century Gothic","sans-serif";color:#002060'>----------------------------------------------------------------------------<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Century Gothic","sans-serif";color:black'>Dana Orzel <o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Century Gothic","sans-serif";color:black'>Great Solar Works, Inc - NABCEP # 051112-136<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Century Gothic","sans-serif";color:black'>E - dana@solarwork.com - Web - solarwork.com <o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Century Gothic","sans-serif";color:black'>O - 970.626.5253 C - 208.721.7003<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Century Gothic","sans-serif";color:black'>"Responsible Technologies for Responsible People since 1988" </span><span style='font-family:"Century Gothic","sans-serif";color:black'><o:p></o:p></span></p><p class=MsoNormal style='background:white'><b><span style='font-size:18.0pt;font-family:Webdings;color:green'>P</span></b><span style='font-size:11.0pt;font-family:"Helvetica","sans-serif";color:navy'> </span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:green'>Please consider the environment before printing this email.</span><span style='font-size:11.0pt;font-family:"Helvetica","sans-serif"'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:black'><o:p> </o:p></span></p></div><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:black'><o:p> </o:p></span></p><div><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";color:windowtext'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'> RE-wrenches [mailto:re-wrenches-bounces@lists.re-wrenches.org] <b>On Behalf Of </b>Ray Walters<br><b>Sent:</b> Sunday, May 31, 2015 12:31 PM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> Re: [RE-wrenches] Voltage Degradation with Uni-Solar laminate<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Yes, amorphous modules degrade faster then crystalline cells. 15 years will really start catching up with you, that's why we always tried to stick to monocrystalline when we could. <br>I think your best option for now is to rewire the array for much higher voltage. Even your current voltage problem aside, the system will run more efficiently at higher voltage: Less current = less voltage drop. I would probably just jump the 4 module sets in series in the combiner box to 8 in series. Should be a quick fix, and really show an improvement. I've seen this same issue with low voltage polys and undersized wiring. Usually the MPP controllers like some room to play with; as soon as the MPP voltage gets close to or less than battery voltage, the current drops off substantially. <br><br><img id="_x0000_i1025" src="cid:image001.jpg@01D09B9F.362B5820"><br><br><br><br><o:p></o:p></p><pre>R.Ray Walters<o:p></o:p></pre><pre>CTO, Solarray, Inc<o:p></o:p></pre><pre>Nabcep Certified PV Installer, <o:p></o:p></pre><pre>Licensed Master Electrician<o:p></o:p></pre><pre>Solar Design Engineer<o:p></o:p></pre><pre>303 505-8760<o:p></o:p></pre><div><p class=MsoNormal>On 5/31/2015 11:55 AM, Luke Christy wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><pre>Hello Off-Grid Wrenches,<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>I recently made a periodic maintenance visit to a residential off-grid system I take care of here in Southern CO, and discovered an interesting problem. <o:p></o:p></pre><pre><o:p> </o:p></pre><pre>This system has an array of 48x Uni-Solar PVL-68 laminate modules applied directly to standing-seam metal roofing. <o:p></o:p></pre><pre><o:p> </o:p></pre><pre>The data logging on the controller (Outback MX-60) indicated that the system was having trouble completing a charge cycle and going to float. Initially I assumed was due to heavy electrical use by the occupants (renters). After a little checking, I noticed that the module string voltage was only about 0.5V above the battery voltage! <o:p></o:p></pre><pre>This was a cool late morning, with full sun, and the array was charging almost 2kW at 54.5V. The module strings were running at 55V. I've noticed the module voltage being lower than I'd like before, but it has never been this low. I suspect this is the real reason the system hasn't been able to complete a charge cycle.<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>By removing the loads I was able to get an open-circuit voltage of 71V, but that still seems pretty low. <o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Has anyone else experienced a voltage degradation issue with the Uni-Solar laminate? What was the expected annual voltage degradation for this technology? <o:p></o:p></pre><pre><o:p> </o:p></pre><pre>These modules do have some age on them. The system was installed about 15 years ago (by a competent installer who is now retired). The system was installed before MPPT controllers were common, so I assume the modules are wired in strings of 4 for 48V nominal. <o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Any experiences or opinions are appreciated.<o:p></o:p></pre><pre>Thanks in advance. <o:p></o:p></pre><pre><o:p> </o:p></pre><pre>-Luke<o:p></o:p></pre><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><pre>Luke Christy<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>NABCEP Certified PV Installation Professional™: Certification #031409-25 <o:p></o:p></pre><pre>NABCEP Certified Solar Heating Installer™: Certification #ST032611-03 <o:p></o:p></pre><pre>CoSEIA Certified PV Installer <o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Solar Gain Services, LLC<o:p></o:p></pre><pre>PO Box 531<o:p></o:p></pre><pre>Monte Vista, CO. 81144<o:p></o:p></pre><pre><a href="mailto:SGSRenewables@Gmail.com">SGSRenewables@Gmail.com</a><o:p></o:p></pre><pre>719.588.3044<o:p></o:p></pre><pre><a href="http://www.sgsrenewables.com">www.sgsrenewables.com</a><o:p></o:p></pre><pre><o:p> </o:p></pre><pre> <o:p></o:p></pre><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><pre>_______________________________________________<o:p></o:p></pre><pre>List sponsored by Redwood Alliance<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a><o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Change listserver email address & settings:<o:p></o:p></pre><pre><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><o:p></o:p></pre><pre><o:p> </o:p></pre><pre>List-Archive: <a href="http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html">http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html</a><o:p></o:p></pre><pre><o:p> </o:p></pre><pre>List rules & etiquette:<o:p></o:p></pre><pre><a href="http://www.re-wrenches.org/etiquette.htm">www.re-wrenches.org/etiquette.htm</a><o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Check out or update participant bios:<o:p></o:p></pre><pre><a href="http://www.members.re-wrenches.org">www.members.re-wrenches.org</a><o:p></o:p></pre><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre></blockquote><p class=MsoNormal><o:p> </o:p></p></div></body></html>