<html><head></head><body bgcolor="#FFFFFF"><div>A while back (3 years)I installed a system (bid spec) for a school that used 215W RECs and D380s on a dual axis tracker. With the ability to monitor the array, I see constant clipping. The modules will usually produce 199Ws regularly. A few days ago we had temps of -34F and clear skies. My array at home had one of its best days this winter. I have Tigos on so I can monitor watts, current, temp and voltage. I was seeing anywhere from 215W to 223W from my modules between 11:30am and 1pm. The modules on the tracker were still producing 199W. I didn't get an irradiance reading that day but my Tigos showed above IMP readings and way above VMP reading that day.</div><div><br></div><div>I've only been doing this for 6 years, so I don't have the experience <span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); ">that some people on this list have, but it seems foolish to me to waste that production. It's kinda site specific, but where I live the cold temps and snow reflection seem like something we should be utilizing. </span></div><div><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); "><br></span></div><div><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); ">I'm interested in the thoughts of others.</span></div><div><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); "><br></span></div><div><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); "><br></span></div><div><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); ">Jesse</span></div><div><br>Sent from my iPad!!!</div><div><br>On Jan 27, 2013, at 5:00 PM, "Marco Mangelsdorf" <<a href="mailto:marco@pvthawaii.com">marco@pvthawaii.com</a>> wrote:<br><br></div><div></div><blockquote type="cite"><div><meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><meta name="Generator" content="Microsoft Word 12 (filtered medium)"><!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
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</o:shapelayout></xml><![endif]--><div class="WordSection1"><p class="MsoNormal"><span style="font-family:"Times New Roman","serif"">I have had a concern for a long time that as PV modules have gone up in output that there is inevitably going to be more and more clipping taking place as they’re paired with comparatively lower output inverters. In effect, matching, say. a 260-watt module with a micro inverter with a max output of 225 watts reduces that 260-watt mod to 225 watts. It’s not a matter of if clipping will take place, but how much and how much actual harvestable energy will be lost.<o:p></o:p></span></p><p class="MsoNormal"><span style="font-family:"Times New Roman","serif""><o:p> </o:p></span></p><p class="MsoNormal"><span style="font-family:"Times New Roman","serif"">Out here in the tropics, even in January with the lower sun angle, we see irradiance levels well above 1,000 watts/square meter range. Take a look at what I copied today from a weather station that we installed at nearby installation.<o:p></o:p></span></p><p class="MsoNormal"><span style="font-family:"Times New Roman","serif""><o:p> </o:p></span></p><p class="MsoNormal"><span style="font-family:"Times New Roman","serif"">Given the clipping issue inherent in using undersized inverters, it seems to me that moving to larger output micros makes a whole lotta sense. I’ve got one of the first installs using the Power-One 250-watt and 300-watt micros and am so far quite impressed. Why use a 225-watt rated micro with a 225-watt or higher output mod when larger micros are now readily available?<o:p></o:p></span></p><p class="MsoNormal"><span style="font-family:"Times New Roman","serif""><o:p> </o:p></span></p><p class="MsoNormal"><span style="font-family:"Times New Roman","serif"">What are the views out there regarding this clipping issue? Is it as minimal as our Enphase friends suggest in their latest white paper or more of an issue as I conclude?<o:p></o:p></span></p><p class="MsoNormal"><span style="font-family:"Times New Roman","serif""><o:p> </o:p></span></p><p class="MsoNormal"><span style="font-family:"Times New Roman","serif"">marco<o:p></o:p></span></p><p class="MsoNormal"><span style="font-family:"Times New Roman","serif""><o:p> </o:p></span></p><p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p><p class="MsoNormal" style="background:white"><span style="font-family:"Times New Roman","serif"">Environmentals from Weather Station at a Hilo, Hawaii installation<o:p></o:p></span></p><p class="MsoNormal" style="background:white"><b><span style="font-family:"Times New Roman","serif";color:black"><o:p> </o:p></span></b></p><p class="MsoNormal" style="background:white"><span style="font-family:"Times New Roman","serif"">Sunday, January 27th 2013, 12:40:00 pm<o:p></o:p></span></p><p class="MsoNormal" style="background:white;vertical-align:middle"><span style="font-family:"Times New Roman","serif""><image001.png><o:p></o:p></span></p><p class="MsoNormal" style="background:white"><span style="font-family:"Times New Roman","serif""> <o:p></o:p></span></p><p class="MsoNormal" style="background:white;vertical-align:middle"><b><span style="font-family:"Times New Roman","serif"">Ambient Temp.</span></b><span style="font-family:"Times New Roman","serif""> 25.30 °C<o:p></o:p></span></p><p class="MsoNormal" style="background:white;vertical-align:middle"><b><span style="font-family:"Times New Roman","serif"">Cell Temp.</span></b><span style="font-family:"Times New Roman","serif""> 41.70 °C<o:p></o:p></span></p><p class="MsoNormal" style="background:white"><span style="font-family:"Times New Roman","serif""> <o:p></o:p></span></p><p class="MsoNormal" style="background:white;vertical-align:middle"><span style="font-family:"Times New Roman","serif""><image002.png><o:p></o:p></span></p><p class="MsoNormal" style="background:white"><span style="font-family:"Times New Roman","serif""> <o:p></o:p></span></p><p class="MsoNormal" style="background:white;vertical-align:middle"><b><span style="font-family:"Times New Roman","serif"">Insolation</span></b><span style="font-family:"Times New Roman","serif""> 127.81 kWh/m²<o:p></o:p></span></p><p class="MsoNormal" style="background:white;vertical-align:middle"><b><span style="font-size:16.0pt;font-family:"Times New Roman","serif"">Irradiance</span></b><b><span style="font-size:16.0pt;font-family:"Times New Roman","serif""> <i>1,175.00</i> W/m²<o:p></o:p></span></b></p><p class="MsoNormal"><o:p> </o:p></p></div></div></blockquote><blockquote type="cite"><div><span>_______________________________________________</span><br><span>List sponsored by Home Power magazine</span><br><span></span><br><span>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a></span><br><span></span><br><span>Options & settings:</span><br><span><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></span><br><span></span><br><span>List-Archive: <a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a></span><br><span></span><br><span>List rules & etiquette:</span><br><span><a href="http://www.re-wrenches.org/etiquette.htm">www.re-wrenches.org/etiquette.htm</a></span><br><span></span><br><span>Check out participant bios:</span><br><span><a href="http://www.members.re-wrenches.org">www.members.re-wrenches.org</a></span><br><span></span><br></div></blockquote></body></html>