<div dir="auto">I always love how what I imagine to be a simple question often sparks a much wider, interesting conversation on this list. <div dir="auto">In this instance, I am dealing with an off- grid client in a colder, snowier, cloudier section of Vermont, but not an extreme environment. The panels are mounted on a fixed, 35 degree rack. </div><div dir="auto"><br></div><div dir="auto">The client is asking if putting heat pans behind the panels would be ok and useful for dealing with sticky snow/ice scenarios. Having never looked into the option, assuming it was probably a bad idea, I told him as much. But, of course he found an internet site that advertises such things specifically for solar panels. </div><div dir="auto"><br></div><div dir="auto">I was fairly skeptical, but since I really had never truly vetted the idea, I figured I would asked all you esteemed colleagues if anyone had any direct experience or knowledge of such things. </div><div dir="auto"><br></div><div dir="auto">So that is what I'm wondering about. Has anyone here had any direct, indirect or hearsay knowledge about devices for melting some amount of snow or ice build up off of panels? I'm not thinking this would be the primary method of clearing them, only a way to help get a sticky layer to release. I imagine it would be controlled by a simple on/off switch that the owner deals with as he deemed necessary.</div><div dir="auto"><br></div><div dir="auto">I am happy to hear everyone's stories about design, methodology, or recommendations for dealing with snow, since this is an ongoing concern in this part of the world (and hopefully will continue to be), but at the moment I am most interested to get feedback about methods of melting snow.</div><div dir="auto"><br></div><div dir="auto">Thanks as always, </div><div dir="auto">Howie</div><div dir="auto">Sun Catcher</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Dec 6, 2024, 1:52 PM Dana Orzel via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div lang="EN-US" link="#467886" vlink="#96607D" style="word-wrap:break-word">
<div class="m_-2588291160239563615WordSection1">
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Century Gothic",sans-serif">Having installed at up to 13,200’ elevation (60° rack mount) and in snow country for most of most of 37 years and dealing with installations by others that almost or
completely come off the roof here is my 0.02:<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Century Gothic",sans-serif"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Century Gothic",sans-serif">Low angle roofs less than 35deg seem to take on most of the damage incidents. Avalanches are most prevalent at 32-35+deg. Avys tend not to slide at less than 32 deg.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Century Gothic",sans-serif">Is the lower edge of the array shaded or partial shade on part of the array with the low angle winter sun? This allows for ice up on the bottom edge or on a section
of the array.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Century Gothic",sans-serif">Is there a drop zone for the snow? I use 5’ min below the leading edge for a mountain install I would increase this to higher.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Century Gothic",sans-serif">I know this sounds obvious - Is there a snow fence or obstruction (door shed roof) below the array?<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Century Gothic",sans-serif"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Century Gothic",sans-serif">I now install esp. on lower angle roofs a mid-third rail & use 50% more contact to the roof points (cheap array life insurance).<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Century Gothic",sans-serif">If using a micro inverter or optimizer – attach this to the panel so it flexes with the panel if necessary not the rail mount system. Watch out for bolts that stick
up close to the back sheet.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Century Gothic",sans-serif"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Century Gothic",sans-serif">Happy Hollar Daze all!<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Century Gothic",sans-serif">_________________________________________________________<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Century Gothic",sans-serif;color:#275317">Dana Orzel
</span><span style="font-size:12.0pt;font-family:"Century Gothic",sans-serif;color:#275317">GREAT SOLAR WORKS!
<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Century Gothic",sans-serif;color:#275317">C – 208.721.7003 E –
</span><a href="mailto:dana@solarwork.com" target="_blank" rel="noreferrer"><span style="font-size:12.0pt;font-family:"Century Gothic",sans-serif;color:#275317;text-decoration:none">dana@solarwork.com</span></a><span style="font-size:12.0pt;font-family:"Century Gothic",sans-serif;color:#275317"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Century Gothic",sans-serif;color:#275317">W - www. <a href="http://greatsolarworks.com" target="_blank" rel="noreferrer">greatsolarworks.com</a>
</span><a href="http://www.solarwork.com/" target="_blank" rel="noreferrer"><span style="font-size:12.0pt;font-family:"Century Gothic",sans-serif;color:#275317;text-decoration:none">www.solarwork.com</span></a><span style="font-size:12.0pt;font-family:"Century Gothic",sans-serif;color:#275317"><u></u><u></u></span></p>
<p class="MsoNormal"><i><u><span style="font-size:12.0pt;font-family:"Century Gothic",sans-serif;color:#275317">“Responsible Technologies for Responsible People since 1988!”<u></u><u></u></span></u></i></p>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
</div>
<br><br><br>---------- Forwarded message ----------<br>From: jay pozner via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank" rel="noreferrer">re-wrenches@lists.re-wrenches.org</a>><br>To: RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank" rel="noreferrer">re-wrenches@lists.re-wrenches.org</a>><br>Cc: jay pozner <<a href="mailto:jay@outpostreconcepts.com" target="_blank" rel="noreferrer">jay@outpostreconcepts.com</a>><br>Bcc: <br>Date: Fri, 6 Dec 2024 17:39:42 +0000<br>Subject: Re: [RE-wrenches] De-icing panels off grid<br>
<div>
<div dir="ltr">
<div>I have gone around this many times on this one. It's interesting to hear all the perspectives of peers whom I greatly respect. In revisiting this I think context is really important. There are so many factors that can add up to "tip" the scales to favor
this idea that one professional might or might not consider. I have seen a fair amount of destruction of PV from snow, and of course the disruption in PV performance which could then of course cascade to battery destruction. In trying to avoid the heat idea,
I have made a secondary (small) array mounted vertically on a wall of a cabin to simply maintain a trickle charge of the batteries of the system during winter months when the cabin isn't being used, in efforts to keep the lead acid batteries topped off. Of
course it's not perfect if the snow water content is high, and there is wind, but in an inter-mountain (dry) snowpack it seems to perform well.</div>
<div><br>
</div>
<div>One idea that I am tilting towards more and more in these unique circumstances is to power the heat source (heat tape, etc) with the generator circuit. Of course there needs to be a reasonable sized generator on site, but for most of my stand alone situations
this is more rule than exception. We can get fancy with a timer (to keep track of daylight hours) and a photosensor to automatically determine if the array is substantially covered, but truthfully I bet a simple switch used in these situations actuated by
the system owner might suffice...</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div>
<div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature">
<div dir="ltr"><span>
<div dir="ltr" style="margin-left:0pt" align="left">
<table style="border:none;border-collapse:collapse">
<colgroup><col width="209"><col width="207"><col width="208"></colgroup>
<tbody>
<tr style="height:0pt">
<td style="border-left:solid #ffffff 1pt;border-right:solid #ffffff 1pt;border-bottom:solid #ffffff 1pt;border-top:solid #ffffff 1pt;vertical-align:top;padding:5pt 5pt 5pt 5pt;overflow:hidden">
<p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt"><img src="https://lh7-us.googleusercontent.com/H6JwbP-UbgUSyuzQV2aWZugNpii3FYf1ETs8YhCQcRHADLAIEmxif4uaIlW9R2auYnIA6Pl8ZMem69UdeUAiEhaTQYP_F0FHFzvYSl17OdVO2a2Wc5XNXfYgFhFBfKZtToiBeqeArsP2T50bTkbdk_M" width="194" height="145" style="color:rgb(0,0,0);font-family:Arial,sans-serif;font-size:14.6667px;margin-left:0px;margin-top:0px"></p>
<p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt"><br>
</p>
<p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt">Jay Pozner</p>
<p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt">(970) 209-0024</p>
<p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Nunito,sans-serif;color:rgb(19,79,92);background-color:transparent;vertical-align:baseline"><br>
</span></p>
</td>
</tr>
</tbody>
</table>
<br>
</div>
</span></div>
</div>
</div>
<br>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Fri, Dec 6, 2024 at 9:27 AM Todd Cory via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank" rel="noreferrer">re-wrenches@lists.re-wrenches.org</a>> wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<font face="georgia" size="2">
<p style="margin:0px;padding:0px;font-family:georgia;font-size:10pt">Yes, in deep snow country tall pole mounts can be expensive... especially with enough room below so the sliding snow never meets the bottom edge of the array. My home system has 5 pole mounts
with the bottom edges ~6' above the ground. <br>
<br>
Now that engineering is mandated, this adds more expense to ensure sure the foundation can support the mechanical forces of this configuration. But shallow angle roof mounts risk having the bottom edge of the modules get ripped off (see attached picture) so
here in the Mount Shasta area, this is the only thing that works.<br>
<br>
There was a thread where people were experimenting with reverse biasing modules to cause them to generate heat. I think boB was working on some kind of possibility for a charge controller option to do this, but I am not sure where that went.<br>
<br>
Todd<br>
<br>
<br>
<img alt=""><br>
<br>
<br>
<br>
</p>
<p style="margin:0px;padding:0px;font-family:georgia;font-size:10pt">On Thursday, December 5, 2024 5:49pm, "Howie Michaelson via RE-wrenches" <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank" rel="noreferrer">re-wrenches@lists.re-wrenches.org</a>> said:<br>
<br>
</p>
<div id="m_-2588291160239563615m_-6667546551480092472SafeStyles1733500191">
<div>Todd,
<div>In general that had been my philosophy, but sometimes pole mounts are just logistically to difficult/ expensive - especially large ones. In general, if it is a windy location, the snow doesn't stick around that long. However, even pole mounts at a steep
angle can get encrusted and if it doesn't get warm enough or sunny, that can stick on the panels for a week or more. I've never considered anything like heat panels or tape, but if there is something that works that doesn't harm the panels, then it might
be a decent option in some cases. </div>
<div>Howie</div>
</div>
<br>
<div class="gmail_quote">
<div class="gmail_attr" dir="ltr">On Thu, Dec 5, 2024, 5:15 PM Todd Cory via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank" rel="noreferrer">re-wrenches@lists.re-wrenches.org</a>> wrote:</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<p style="margin:0px;padding:0px;font-family:georgia;font-size:10pt">Passive works best. In big snow country here, I learned the hard way to only do pole mounts... and set the angle steep in the winter. The snow slides off and all is fine.<br>
<br>
Todd<br>
<br>
<br>
<br>
<br>
</p>
<p style="margin:0px;padding:0px;font-family:georgia;font-size:10pt">On Thursday, December 5, 2024 1:01pm, "Kirk Herander via RE-wrenches" <<a rel="noreferrer noreferrer" href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank">re-wrenches@lists.re-wrenches.org</a>>
said:<br>
<br>
</p>
<div id="m_-2588291160239563615m_-6667546551480092472m_2044037087436129766SafeStyles1733436785">
<div>
<div><a rel="noreferrer noreferrer" href="https://glasscareexperts.com/solar-glass-protection/" target="_blank">https://glasscareexperts.com/solar-glass-protection/</a></div>
I’ve never tried it but just heard about these people. From the bio they are the original makers of rain X, but they customized a product, several of them, to clean Pv panels and they also mentioned it can help to shed rain and snow.</div>
<div>By the way, Rainx is not approved for such an application.</div>
<div><br>
<div>
<div class="gmail_signature" dir="ltr">
<div dir="ltr">
<p class="MsoNormal" style="padding:0px;font-family:Arial;font-size:16px;margin:0in 0in 0.0001pt;color:rgb(0,0,0)">
<span style="font-size:10pt;font-family:Arial"><a style="font-family:Arial" rel="noreferrer noreferrer" name="m_-2588291160239563615_m_-6667546551480092472_m_2044037087436129766_SignatureSanitizer__MailAutoSig"></a><strong style="font-family:Arial">Kirk Herander / </strong><strong style="font-family:Arial"><a style="font-family:Arial;color:blue" title="Send an email to kirkh@vermont.solar; Send an email to kirkh@vermont.solar" rel="noreferrer noreferrer" href="mailto:kirkh@vermont.solar" target="_blank">kirkh@vermont.solar</a></strong></span></p>
<p class="MsoNormal" style="padding:0px;font-family:Arial;font-size:16px;margin:0in 0in 0.0001pt;color:rgb(0,0,0)">
<span style="font-size:10pt;font-family:Arial"><strong style="font-family:Arial">Owner|Principal, VT Solar, LLC</strong></span></p>
<p class="MsoNormal" style="padding:0px;font-family:Arial;font-size:16px;margin:0in 0in 0.0001pt;color:rgb(0,0,0)">
<span style="font-size:10pt;font-family:Arial"><strong style="font-family:Arial"><em style="font-family:Arial">Celebrating our 33<sup style="font-family:Arial">st</sup> Anniversary 1991-2024!!</em></strong></span></p>
<p class="MsoNormal" style="padding:0px;font-family:Arial;font-size:16px;margin:0in 0in 0.0001pt;color:rgb(0,0,0)">
<span style="font-size:10pt;font-family:Arial">dba Vermont Solar Engineering</span></p>
<p class="MsoNormal" style="padding:0px;font-family:Arial;font-size:16px;margin:0in 0in 0.0001pt;color:rgb(0,0,0)">
<span style="font-size:10pt;font-family:Arial">802.559.1225</span></p>
</div>
</div>
</div>
</div>
<div><br>
<div class="gmail_quote">
<div class="gmail_attr" dir="ltr">On Thu, Dec 5, 2024 at 2:19 PM Howie Michaelson via RE-wrenches <<a rel="noreferrer noreferrer" href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank">re-wrenches@lists.re-wrenches.org</a>> wrote:</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">
<div>
<div class="gmail_default" style="font-family:verdana,sans-serif">Has anyone successfully used heat panels or cables to melt iced-over panels (ie. without damaging the panels)? In heavy snow country, or over periods of freeze/thaw when pelty slushy snow sticks
and freezes to panels, it would be nice to have a safe method of clearing them, especially off-grid. I remember discussions of the futility of backfeeding panels to heat them up to accomplish the same, but not about heat tape or pans that might be worth trying.</div>
<div class="gmail_default" style="font-family:verdana,sans-serif">Thanks,</div>
Howie Michaelson</div>
<div>
<div class="gmail_default" style="font-family:verdana,sans-serif">Sun Catcher</div>
</div>
</div>
_______________________________________________<br>
List sponsored by Redwood Alliance<br>
<br>
Pay optional member dues here: <a rel="noreferrer noreferrer noreferrer" href="http://re-wrenches.org" target="_blank">
http://re-wrenches.org</a><br>
<br>
List Address: <a rel="noreferrer noreferrer" href="mailto:RE-wrenches@lists.re-wrenches.org" target="_blank">
RE-wrenches@lists.re-wrenches.org</a><br>
<br>
Change listserver email address & settings:<br>
<a rel="noreferrer noreferrer noreferrer" href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br>
<br>
There are two list archives for searching. When one doesn't work, try the other:<br>
<a rel="noreferrer noreferrer noreferrer" href="https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/" target="_blank">https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/</a><br>
<a rel="noreferrer noreferrer noreferrer" href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br>
<br>
List rules & etiquette:<br>
<a rel="noreferrer noreferrer noreferrer" href="http://www.re-wrenches.org/etiquette.htm" target="_blank">http://www.re-wrenches.org/etiquette.htm</a><br>
<br>
Check out or update participant bios:<br>
<a rel="noreferrer noreferrer noreferrer" href="http://www.members.re-wrenches.org" target="_blank">http://www.members.re-wrenches.org</a><br>
<br>
</blockquote>
</div>
</div>
</div>
<br>
<br>
<br>
Sent from Finest Planet WebMail.<br>
_______________________________________________<br>
List sponsored by Redwood Alliance<br>
<br>
Pay optional member dues here: <a rel="noreferrer noreferrer noreferrer" href="http://re-wrenches.org" target="_blank">
http://re-wrenches.org</a><br>
<br>
List Address: <a rel="noreferrer noreferrer" href="mailto:RE-wrenches@lists.re-wrenches.org" target="_blank">
RE-wrenches@lists.re-wrenches.org</a><br>
<br>
Change listserver email address & settings:<br>
<a rel="noreferrer noreferrer noreferrer" href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br>
<br>
There are two list archives for searching. When one doesn't work, try the other:<br>
<a rel="noreferrer noreferrer noreferrer" href="https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/" target="_blank">https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/</a><br>
<a rel="noreferrer noreferrer noreferrer" href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br>
<br>
List rules & etiquette:<br>
<a rel="noreferrer noreferrer noreferrer" href="http://www.re-wrenches.org/etiquette.htm" target="_blank">http://www.re-wrenches.org/etiquette.htm</a><br>
<br>
Check out or update participant bios:<br>
<a rel="noreferrer noreferrer noreferrer" href="http://www.members.re-wrenches.org" target="_blank">http://www.members.re-wrenches.org</a><br>
<br>
</blockquote>
</div>
</div>
</font><br>
<br>
<br>
Sent from Finest Planet WebMail.<br>
_______________________________________________<br>
List sponsored by Redwood Alliance<br>
<br>
Pay optional member dues here: <a href="http://re-wrenches.org" rel="noreferrer noreferrer" target="_blank">
http://re-wrenches.org</a><br>
<br>
List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" target="_blank" rel="noreferrer">
RE-wrenches@lists.re-wrenches.org</a><br>
<br>
Change listserver email address & settings:<br>
<a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" rel="noreferrer noreferrer" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br>
<br>
There are two list archives for searching. When one doesn't work, try the other:<br>
<a href="https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/" rel="noreferrer noreferrer" target="_blank">https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/</a><br>
<a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" rel="noreferrer noreferrer" target="_blank">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br>
<br>
List rules & etiquette:<br>
<a href="http://www.re-wrenches.org/etiquette.htm" rel="noreferrer noreferrer" target="_blank">http://www.re-wrenches.org/etiquette.htm</a><br>
<br>
Check out or update participant bios:<br>
<a href="http://www.members.re-wrenches.org" rel="noreferrer noreferrer" target="_blank">http://www.members.re-wrenches.org</a><br>
<br>
</blockquote>
</div>
</div>
_______________________________________________<br>
List sponsored by Redwood Alliance<br>
<br>
Pay optional member dues here: <a href="http://re-wrenches.org" rel="noreferrer noreferrer" target="_blank">http://re-wrenches.org</a><br>
<br>
List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" target="_blank" rel="noreferrer">RE-wrenches@lists.re-wrenches.org</a><br>
<br>
Change listserver email address & settings:<br>
<a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" rel="noreferrer noreferrer" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br>
<br>
There are two list archives for searching. When one doesn't work, try the other:<br>
<a href="https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/" rel="noreferrer noreferrer" target="_blank">https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/</a><br>
<a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" rel="noreferrer noreferrer" target="_blank">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br>
<br>
List rules & etiquette:<br>
<a href="http://www.re-wrenches.org/etiquette.htm" rel="noreferrer noreferrer" target="_blank">http://www.re-wrenches.org/etiquette.htm</a><br>
<br>
Check out or update participant bios:<br>
<a href="http://www.members.re-wrenches.org" rel="noreferrer noreferrer" target="_blank">http://www.members.re-wrenches.org</a><br>
<br>
</blockquote></div>