<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:arial,helvetica,sans-serif;font-size:12pt">Enphase has been very clear that the M-190 can be paired with modules up to 230 watts DC, with a slight amount of power loss<br><div> </div>Nick Soleil<br>Project Manager<br>Advanced Alternative Energy Solutions, LLC<br>PO Box 657<br>Petaluma, CA 94953<br>Cell: 707-321-2937<br>Office: 707-789-9537<br>Fax: 707-769-9037<div><br></div><div style="font-family: arial,helvetica,sans-serif; font-size: 12pt;"><br><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><font face="Tahoma" size="2"><hr size="1"><b><span style="font-weight: bold;">From:</span></b> Randy <randy@positiveenergysolar.com><br><b><span style="font-weight: bold;">To:</span></b> RE-wrenches <re-wrenches@lists.re-wrenches.org><br><b><span style="font-weight: bold;">Sent:</span></b> Sun, January 16,
2011 2:35:27 PM<br><b><span style="font-weight: bold;">Subject:</span></b> Re: [RE-wrenches] Enphase and oversizing<br></font><br>
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--></style><div class="WordSection1"><p class="MsoNormal"><span style="color: rgb(31, 73, 125);">Hi Marco,</span></p><p class="MsoNormal"><span style="color: rgb(31, 73, 125);">I would doubt you would have clipping where you except for edge of cloud effect but here are that factors that we considered:</span></p><p class="MsoListParagraph" style=""><span style="color: rgb(31, 73, 125);"><span style="">1.<span style="font: 7pt "Times New Roman";"> </span></span></span><span style="color: rgb(31, 73, 125);"> A low coefficient of power module such as sanyo or thin film running at lower temperatures would mean the module runs closer to its rating depending on ambient temperature</span></p><p class="MsoListParagraph" style=""><span style="color: rgb(31, 73, 125);"><span style="">2.<span style="font: 7pt "Times New Roman";"> </span></span></span><span style="color:
rgb(31, 73, 125);">In cold, high altitude areas such as Colorado and NM where the module temp frequently is close to 25 degree C</span></p><p class="MsoListParagraph" style=""><span style="color: rgb(31, 73, 125);"><span style="">3.<span style="font: 7pt "Times New Roman";"> </span></span></span><span style="color: rgb(31, 73, 125);">In ground mount or windy situations where the delta T to ambient is very small (might apply to you)</span></p><p class="MsoListParagraph" style=""><span style="color: rgb(31, 73, 125);"><span style="">4.<span style="font: 7pt "Times New Roman";"> </span></span></span><span style="color: rgb(31, 73, 125);">Where irradiance is regularly running above 1000W/m2 and the array is mounted on a tracker or when there is snow on the ground and albedo is reflecting more sunlight.</span></p><p class="MsoNormal"><span style="color:
rgb(31, 73, 125);"> </span></p><p class="MsoNormal"><span style="color: rgb(31, 73, 125);">We have seen output clipping of any inverter that is rated less than the module STC DC watts in NM including enphase.</span></p><p class="MsoNormal"><span style="color: rgb(31, 73, 125);"> </span></p><p class="MsoNormal"><span style="color: rgb(31, 73, 125);">Thanks,</span></p><p class="MsoNormal"><span style="color: rgb(31, 73, 125);">Randy</span></p><div><p class="MsoNormal"><span style="font-size: 10pt; font-family: "sans-serif"; color: rgb(31, 73, 125);">Randy Sadewic</span><span style="font-size: 12pt; font-family: "serif"; color: rgb(31, 73, 125);"></span></p><p class="MsoNormal"><span style="font-size: 10pt; font-family: "sans-serif"; color: rgb(31, 73, 125);">Positive Energy</span><span style="font-size: 12pt; font-family: "serif"; color: rgb(31, 73, 125);"></span></p><p class="MsoNormal"><span
style="font-size: 12pt; font-family: "serif"; color: rgb(31, 73, 125);"> </span></p><p class="MsoNormal"><span style="font-size: 10pt; font-family: "sans-serif"; color: rgb(31, 73, 125);">Office: 505 424-1112</span><span style="font-size: 12pt; font-family: "serif"; color: rgb(31, 73, 125);"></span></p></div><p class="MsoNormal"><span style="font-size: 10pt; font-family: "sans-serif"; color: rgb(31, 73, 125);">Cell: 505 570-0137</span><span style="color: rgb(31, 73, 125);"></span></p><div><div style="border-width: 1pt medium medium; border-style: solid none none; border-color: rgb(181, 196, 223) -moz-use-text-color -moz-use-text-color; padding: 3pt 0in 0in;"><p class="MsoNormal"><b><span style="font-size: 10pt; font-family: "sans-serif"; color: windowtext;">From:</span></b><span style="font-size: 10pt; font-family: "sans-serif"; color: windowtext;">
re-wrenches-bounces@lists.re-wrenches.org [mailto:re-wrenches-bounces@lists.re-wrenches.org] <b>On Behalf Of </b>Kent Osterberg<br><b>Sent:</b> Saturday, January 15, 2011 6:13 PM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> Re: [RE-wrenches] Enphase and oversizing</span></p></div></div><p class="MsoNormal"> </p><p class="MsoNormal">Marco,<br><br>Enphase has a white paper on this topic that seems consistent with observations. The results depend on the roof and the location. But even on a 12:12 roof in Denver they compute less than 0.6% annual loss with new clean 235-watt modules. I've looked for clipping events on systems with Sharp 235-watt modules that I've installed on 4:12 roofs and haven't seen much - rarely are they even near 199 watts for a few minutes. Obviously it'll be more significant with larger modules like the SW 245, but I doubt that occasional clipping that amounts to less than 1% of the possible annual
output should be characterized as wasting the customer's money. That much can be lost in selecting a different inverter.<br><br>I suspect and hope that a larger inverter is in the works. But in the mean time I see putting 245-watt modules on the 190-watt inverters as working the inverter hard. Would you hesitate to put 2400 watts of PV modules on a 2-kW inverter? <br><br>Kent Osterberg<br>Blue Mountain Solar, Inc.<br><br><br>Marco Mangelsdorf wrote: </p><p class="MsoNormal">To those of you installing Enphases.</p><p class="MsoNormal"> </p><p class="MsoNormal">Other than their 210 only working with Sanyo and SunPower modules, the vast majority of other mods only work with the Enphase 190.</p><p class="MsoNormal"> </p><p class="MsoNormal">Question: what’s the max size module that you’re comfortable using with the Enphase 190?</p><p class="MsoNormal"> </p><p class="MsoNormal">In there here parts I’m seeing competitors
pairing the Enphase 190 with modules in the 230+ watt range. Some are even pairing the 190 with the SolarWorld 245. Talk about wasting the customer’s money….</p><p class="MsoNormal"> </p><p class="MsoNormal">This strikes me as a bad design that essentially has the homeowner throwing away some of his/her money on unused PV horsepower. Here in the tropics, where the edge-of-cloud effect can be seen on a regular basis, I see DC nameplate AND higher coming out on the AC side of my systems.</p><p class="MsoNormal"> </p><p class="MsoNormal">I’m wondering where others are on this question of oversizing.</p><p class="MsoNormal"> </p><p class="MsoNormal">Thanks,</p><p class="MsoNormal">marco</p><p class="MsoNormal"> </p></div><meta http-equiv="x-dns-prefetch-control" content="on"></div></div>
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