<div dir="ltr">I found the latest module "rightsizing" paper by Enphase pretty interesting. It does stand to reason that there are a lot of hours in the day where the inverter is producing less than rated power, so increasing the module size makes sense. Obviously there is an optimum point in every system where clipping exceeds gains, but that's virtually impossible to nail down due to so many factors being involved. I think the point would be that PV mods are coming down in price so much that "rightsizing" is basically equivalent to "upsizing," within reason, of course. Spending an extra 25% on PV might increase the installed system cost by 5-10%.<br>
<br><div id="WISESTAMP_SIG_gmail_session"><div style="font-size:13px;font-family:Verdana,Arial,Helvetica,sans-serif"><div style="margin:0 0 8px 0"><p style="margin:0"><span style="color:#808080"><strong>Jason Szumlanski</strong></span></p>
<p style="margin:0"><span style="color:#808080"><em>Fafco Solar<br></em></span><br></p></div></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Sun, Jan 27, 2013 at 6:00 PM, Marco Mangelsdorf <span dir="ltr"><<a href="mailto:marco@pvthawaii.com" target="_blank">marco@pvthawaii.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div lang="EN-US" link="blue" vlink="purple"><div><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.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman","serif""><u></u> <u></u></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.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman","serif""><u></u> <u></u></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?<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman","serif""><u></u> <u></u></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?<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman","serif""><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-family:"Times New Roman","serif"">marco<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman","serif""><u></u> <u></u></span></p><p class="MsoNormal"><span style="color:#1f497d"><u></u> <u></u></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<u></u><u></u></span></p><p class="MsoNormal" style="background:white"><b><span style="font-family:"Times New Roman","serif""><u></u> <u></u></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<u></u><u></u></span></p><p class="MsoNormal" style="background:white;vertical-align:middle">
<span style="font-family:"Times New Roman","serif""><img width="55" height="55" alt="https://easyview.auroravision.net/easyview/images/icons/weather/temp-red.png"><u></u><u></u></span></p><p class="MsoNormal" style="background:white">
<span style="font-family:"Times New Roman","serif""> <u></u><u></u></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<u></u><u></u></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<u></u><u></u></span></p>
<p class="MsoNormal" style="background:white"><span style="font-family:"Times New Roman","serif""> <u></u><u></u></span></p><p class="MsoNormal" style="background:white;vertical-align:middle"><span style="font-family:"Times New Roman","serif""><img width="55" height="55" alt="https://easyview.auroravision.net/easyview/images/icons/weather/sun-yellow.png"><u></u><u></u></span></p>
<p class="MsoNormal" style="background:white"><span style="font-family:"Times New Roman","serif""> <u></u><u></u></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<u></u><u></u></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<u></u><u></u></span></b></p>
<p class="MsoNormal"><u></u> </p></div></div></blockquote></div></div></div>