<html><body bgcolor="#FFFFFF"><div>The snow removal system really interests me. Being in northern Minnesota, we get a lot of it. I have one student that is responsible for snow removal now, but I haven't come up with anything else. I will be watching this thread intently!</div><div><br></div><div>Jesse </div><div><br>Sent from my iPhone</div><div><br>On Jan 3, 2011, at 8:10 AM, "Jason Szumlanski" <<a href="mailto:Jason@fafcosolar.com">Jason@fafcosolar.com</a>> wrote:<br><br></div><div></div><blockquote type="cite"><div><div class="WordSection1"><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">One idea would be to put each microinverter on a separate A/C circuit and measure the current using a device like an eGauge or a revenue grade metering device. That would give you backup/redundancy for the Enphase numbers. With 16 modules/circuits in your system, that\u2019s not too difficult to monitor.<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:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">For the second system, what about putting the system on a tracking rack that tilts to vertical once a day in the morning to dump snow. We don\u2019t deal with much snow down here in Florida, so I\u2019m not sure if that would 100% dump the snow off and how ice accumulation is dealt with\u2026 Born in Winnipeg, but left the snow behind many years ago\u2026<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><p class="MsoNormal"><span style="font-family:"Cambria","serif";color:#1F497D">Jason Szumlanski<o:p></o:p></span></p><p class="MsoNormal"><span style="font-family:"Cambria","serif";color:#1F497D">Fafco Solar<o:p></o:p></span></p></div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><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"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a> [mailto:re-wrenches-bounces@lists.re-wrenches.org] <b>On Behalf Of </b>Rob Harlan<br><b>Sent:</b> Monday, January 03, 2011 1:25 AM<br><b>To:</b> <a href="mailto:re-wrenches@lists.re-wrenches.org"><a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a></a><br><b>Subject:</b> [RE-wrenches] Reference PV System<o:p></o:p></span></p></div></div><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><br>I am working with the City of Edmonton, Alberta to develop a reference system. The intent is to provide accurate data for owners of systems within the city limits to use to verify their system performance. It is seen as a great way to insure quality installations under their municipal grant program, as well as a way to provide some real life performance data for system sizing and installation recommendations. The City is considering tying the dispersal of system grants to verified performance. (We are hoping to eventually have a municipal performanced-based FIT, but until then...) <br><br>At this point the plan is to permanently install modules at eight different orientations to imitate common installations:</span><o:p></o:p></p><p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">True South 18.4 degrees ( Equivalent to a 4 in 12 pitch roof)<br>True South 26.6 degrees (Equivalent to a 6 in 12 pitch roof)<br>True South 45.0 degrees (Equivalent to a 12 in 12 pitch roof)<br>True South 53.0 degrees (Latitude)<br>True South 70.0 degree pitch (the estimated best angle for year round performance in Edmonton when snow is not removed)<br>True south 90 degree pitch (Equivalent to a vertical wall installation)<br>SE 18.4 degrees ( Equivalent to a 4 in 12 pitch roof)<br>SW 18.4 degrees ( Equivalent to a 4 in 12 pitch roof)</span><o:p></o:p></p><p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">We will probably install two modules at each orientation to provide redundancy to back up possible equipment malfunction. Each module will have its own micro-inverter uploading data to a website. The system will be installed on a municipal building, probably a firehouse.<br><br>We are also considering installing a second, identical system which would have snow removed once a day (at daybreak). This would provide owners considering snow removal with comparative data. The challenge here is how to consistently remove accumulated snow. We probably will not be able to get municipal staff to carry this out so we are looking into automated systems.<br><br>So gentlemen I would love to get your thoughts:<br><br><b>Anybody familiar with PV reference systems developed by other municipalities? Have they been successful?<br>Have you found the Enphase Envoy to be consistently accurate?<br><br>Does anyone have a reliable automatic snow removal scheme with a track record?</b> We are putting it out to the University of Alberta mechanical engineering department to see what they come up with but I know this has been grappled with many times before.<br><br>Thanks <u>much</u> in advance for your input.<br>Rob<br>Rob Harlan<br>Executive Director<br>Solar Energy Society of Alberta<br><a href="http://www.solaralberta.ca">www.solaralberta.ca</a><br><a href="office@solaralberta.ca">office@solaralberta.ca</a><br>(780) 439-5608<br><br><br><br><br></span><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"><a href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a></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"><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></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>