<div dir="ltr">Another thing that makes a big difference here in Colorado is to use dark colored frames and cells as opposed to silver frames and lighter colored cells.  We get a lot of cold but clear days and dark color makes a huge difference in how quickly shedding will occur.  This same phenomenon will work against you in the summer but for off-grid our design day is mid-winter typically.<div><br></div><div>We prefer pole mounts where snow can be broomed off and tilts optimized throughout the winter.</div><div><br></div><div>Cheers</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Mar 27, 2015 at 10:15 AM, Dave <span dir="ltr"><<a href="mailto:dave@independentpowerllc.com" target="_blank">dave@independentpowerllc.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="#000000" vlink="#000000"><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I will back up your opinion that open back has not a lot to do with it. I have several arrays that I care for here in my off grid neighborhood and some are tilted 20 degrees off of roofs to 45 degree array angle and one is a TPM that is set at 60 degrees for winter and all of these experience severe snow cover problems unless it warms up for a significant amount of time, or the roof rake is used.<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">As you know, building the rack far off of the roof AND minimize costs do not go together. Extra material and extra strength for wind loads.<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Dave<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></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""> RE-wrenches [mailto:<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank">re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b><a href="mailto:dan@foxfire-energy.com" target="_blank">dan@foxfire-energy.com</a><br><b>Sent:</b> Friday, March 27, 2015 12:00 PM<br><b>To:</b> RE-wrenches</span></p><div><div class="h5"><br><b>Subject:</b> Re: [RE-wrenches] Tilt Racking vs Roof Mount for Shedding snow<u></u><u></u></div></div><p></p></div></div><div><div class="h5"><p class="MsoNormal"><u></u> <u></u></p><div><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black">My customers neighbor has 1.1k of 110W panels on a tilt up rack set at about 45° (Some 20° from the roof). Her array pretty much stayed clear all winter with minimal futzing. My customer has a 7.2k array (Four rows of six) in portrait, mounted on unirack solar mount on an asphalt tile roof at around 45° (Off Grid), on an unheated garage. My customers panels got a thin coat of ice on the array early on that held some 12'' of snow all winter. We did set it up so the bottom two rows were on their own CC and could be cleared from the ground, but they never did totally clear. The neighbor now wants to expand her system, is willing to build a shed for the array, but wants me to elevate the array as far off the roof as possible (and minimize costs). I'm working on my diplomacey here. I suggested it might be a combination of factors that contributed to my customers array not sheding, but the neighbor insists it has something to do with the array being open backed. I offered to put it out to the group for opinions. Thanks db<br> <u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black"><u></u> <u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black"><br>Dan Brown<br>Foxfire Energy Corp.<br>Renewable Energy Systems<br><a href="tel:%28802%29-483-2564" value="+18024832564" target="_blank">(802)-483-2564</a><br><a href="http://www.Foxfire-Energy.com" target="_blank"><span style="color:windowtext">www.Foxfire-Energy.com</span></a><br>NABCEP #092907-44<u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black"><img border="0" width="224" height="107" src="cid:image001.png@01D06886.B7CF8000"><u></u><u></u></span></p></div><div><p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black"><u></u> <u></u></span></p></div><blockquote style="border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 6.0pt;margin-left:6.0pt;margin-top:5.0pt;margin-bottom:5.0pt"><div><p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black">-------- Original Message --------<br>Subject: Re: [RE-wrenches] Tilt Racking vs Roof Mount for Shedding snow<br>From: "Dave" <<a href="mailto:dave@independentpowerllc.com" target="_blank"><span style="color:windowtext">dave@independentpowerllc.com</span></a>><br>Date: Fri, March 27, 2015 10:32 am<br>To: "'RE-wrenches'" <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank"><span style="color:windowtext">re-wrenches@lists.re-wrenches.org</span></a>><u></u><u></u></span></p><div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Dan,</span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">What do you mean by "tilt up racking". Would an example be a rack that adds 15 degrees to a 5/12 roof? Good idea (as long as wind load is taken care of) for cold snow country (certainly for off grid) to get the tilt angle higher which helps with snow shedding. BUT if it's super cold like this winter here in northern New England nothing helps as much as a snow rake. </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">On a side note. I had a couple of monitored grid tied systems with second story roof top arrays that produced very little power from January through second week of March. 80% less kWh than similar first story roof top arrays where the homeowner raked off snow. It was so cold that in one period this winter that it did not get over 30 degrees F for 48 consecutive days here, with many nights at 15 to 30 below zero. February was the coldest on record (since 1886) with temps that were 15 degrees below average for the month. No snow shedding going on at all. </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">On another type of array. My adjustable ground mount here set at 90 degrees had a great winter as I regularly saw 1,750 to 1,950W out of my Apollo CC from a 1,440W array on sunny days because of MPPT and the reflective bounce of sunlight off the snow in front of the array. I never have to touch those modules from mid November, when I tilt them to 90 degrees, until after it stops snowing significantly (mid April usually).</span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Best,</span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Dave</span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">David Palumbo </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Independent Power LLC</span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">462 Solar Way Drive</span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Hyde Park, VT 05655</span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><a href="tel:802-888-7194" value="+18028887194" target="_blank">802-888-7194</a></span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div><div><div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0in 0in 0in"><div><p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:black">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:black"> RE-wrenches [<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank"><u><span style="color:blue">mailto:re-wrenches-bounces@lists.re-wrenches.org</span></u></a>] <b>On Behalf Of </b><a href="mailto:dan@foxfire-energy.com" target="_blank"><u><span style="color:blue">dan@foxfire-energy.com</span></u></a><br><b>Sent:</b> Friday, March 27, 2015 8:19 AM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> [RE-wrenches] Tilt Racking vs Roof Mount for Shedding snow</span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div></div></div><div><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:black"> <u></u><u></u></span></p></div><div><div><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black"> </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div></div><div><div><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black"> </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div></div><div><div><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black">Hi Guys, I have a customer who seems convinced that tilt up racking sheds snow better than conventional roof mounted arrays (irregardless of angle or panel manufacturer). Anyone else find this is true? Thanks db</span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div></div><div><div><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black"> </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div></div><div><div><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black"> </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div></div><div><div><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black"> </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div></div><div><div><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black">Dan Brown<br>Foxfire Energy Corp.<br>Renewable Energy Systems<br><a href="tel:%28802%29-483-2564" value="+18024832564" target="_blank">(802)-483-2564</a><br><a href="http://www.Foxfire-Energy.com" target="_blank"><u><span style="color:blue">www.Foxfire-Energy.com</span></u></a><br>NABCEP #092907-44</span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div></div><div><div><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black"><img border="0" width="224" height="107" src="cid:image001.png@01D06886.B7CF8000"></span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div></div><div><div><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black"> </span><span style="font-family:"Verdana","sans-serif";color:black"><u></u><u></u></span></p></div></div></div><div class="MsoNormal" align="center" style="text-align:center"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif";color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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div><br></div><div><font color="#305A78" face="'times new roman', serif"><br></font></div><div><br></div>Mac Lewis<br><br><span style="font-family:'Times New Roman';font-size:medium;color:rgb(255,153,0)"><b><font face="Arial, Helvetica, sans-serif" size="3"><p align="left"><font color="#000000" face="Verdana, Arial, Helvetica, sans-serif"><span style="font-size:small"><span style="font-family:arial;font-weight:normal;color:rgb(48,90,120)"><font face="'times new roman', serif">"Yo solo sé que no sé nada." </font><span style="font-weight:700;color:rgb(104,104,104)"><font face="'times new roman', serif">-Sócrates</font></span></span></span></font></p></font></b></span></div>
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