--- Begin Message ---
Howie, We have never tried active ice melting systems, but did have a client (
USCG) try various methods and ultimately gave up for a variety of reasons.
Based on that hearsay evidence I would advise against attempting any sort of
active Ice melting system. For what it is worth wind farm operators used to use
Mop and Glo on turbine rotors to help shed Ice, dirt, and insect contamination
and it resulted in noticeable improvement. I have not heard of anybody trying
that on Solar, but it would be an easy cheap experiment to treat one or two
panels in an array to get a comparison.
Pieter Huebner
Project Manager
Off Grid Enterprises
From: RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> On Behalf Of
Howie Michaelson via RE-wrenches
Sent: Friday, December 6, 2024 1:30 PM
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Cc: Howie Michaelson <howie.michael...@gmail.com>
Subject: Re: [RE-wrenches] Panel installation in snow country 0.02
I always love how what I imagine to be a simple question often sparks a much
wider, interesting conversation on this list.
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.
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.
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.
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.
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.
Thanks as always,
Howie
Sun Catcher
On Fri, Dec 6, 2024, 1:52 PM Dana Orzel via RE-wrenches
<re-wrenches@lists.re-wrenches.org<mailto:re-wrenches@lists.re-wrenches.org>>
wrote:
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:
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.
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.
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.
I know this sounds obvious - Is there a snow fence or obstruction (door shed
roof) below the array?
I now install esp. on lower angle roofs a mid-third rail & use 50% more contact
to the roof points (cheap array life insurance).
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.
Happy Hollar Daze all!
_________________________________________________________
Dana Orzel GREAT SOLAR WORKS!
C – 208.721.7003 E – d...@solarwork.com<mailto:d...@solarwork.com>
W - www. greatsolarworks.com<http://greatsolarworks.com>
www.solarwork.com<http://www.solarwork.com/>
“Responsible Technologies for Responsible People since 1988!”
---------- Forwarded message ----------
From: jay pozner via RE-wrenches
<re-wrenches@lists.re-wrenches.org<mailto:re-wrenches@lists.re-wrenches.org>>
To: RE-wrenches
<re-wrenches@lists.re-wrenches.org<mailto:re-wrenches@lists.re-wrenches.org>>
Cc: jay pozner <j...@outpostreconcepts.com<mailto:j...@outpostreconcepts.com>>
Bcc:
Date: Fri, 6 Dec 2024 17:39:42 +0000
Subject: Re: [RE-wrenches] De-icing panels off grid
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.
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...
[https://lh7-us.googleusercontent.com/H6JwbP-UbgUSyuzQV2aWZugNpii3FYf1ETs8YhCQcRHADLAIEmxif4uaIlW9R2auYnIA6Pl8ZMem69UdeUAiEhaTQYP_F0FHFzvYSl17OdVO2a2Wc5XNXfYgFhFBfKZtToiBeqeArsP2T50bTkbdk_M]
Jay Pozner
(970) 209-0024
On Fri, Dec 6, 2024 at 9:27 AM Todd Cory via RE-wrenches
<re-wrenches@lists.re-wrenches.org<mailto:re-wrenches@lists.re-wrenches.org>>
wrote:
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.
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.
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.
Todd
On Thursday, December 5, 2024 5:49pm, "Howie Michaelson via RE-wrenches"
<re-wrenches@lists.re-wrenches.org<mailto:re-wrenches@lists.re-wrenches.org>>
said:
Todd,
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.
Howie
On Thu, Dec 5, 2024, 5:15 PM Todd Cory via RE-wrenches
<re-wrenches@lists.re-wrenches.org<mailto:re-wrenches@lists.re-wrenches.org>>
wrote:
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.
Todd
On Thursday, December 5, 2024 1:01pm, "Kirk Herander via RE-wrenches"
<re-wrenches@lists.re-wrenches.org<mailto:re-wrenches@lists.re-wrenches.org>>
said:
https://glasscareexperts.com/solar-glass-protection/
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.
By the way, Rainx is not approved for such an application.
Kirk Herander / kirkh@vermont.solar<mailto:kirkh@vermont.solar>
Owner|Principal, VT Solar, LLC
Celebrating our 33st Anniversary 1991-2024!!
dba Vermont Solar Engineering
802.559.1225
On Thu, Dec 5, 2024 at 2:19 PM Howie Michaelson via RE-wrenches
<re-wrenches@lists.re-wrenches.org<mailto:re-wrenches@lists.re-wrenches.org>>
wrote:
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.
Thanks,
Howie Michaelson
Sun Catcher
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