Heat tape on the back of the panel to melt snow?

[bcroe]

But... But what if it were heat tape and right on the frame - on the surface? It seems to me that it’s the lip of the frame, on the edge of the face lowest down, that’s preventing the snow from just sliding off. Why not just run heat tape right there? Or. Ha. Ha ha. Why not just make panels and housings that are flat on top? What the heck is up with the frames that catch things, anyway?

Let us know what you achieve. Bruce Roe

[TooMuchSnow]

Well, I do have to work with what I have... Fixed slope, all due South, all portrait (in this section).

Bummer about non conduction in the pole. Makes sense but sigh. Gotta get a new broom anyway - this one’s not long enough.

2B8EF9C0-D65B-4416-8A0A-4CDF386576EF.jpeg After clearing what I could up top.
7704ECC6-B7BE-41CA-8C84-2F4F72E95416.jpeg Before (after clearing the bottom yesterday).

Before anything on the main sections and after (hopefully attached and couldn’t clear anything on the right set).



I guess... Looking through the historical data this winter we’ve made more electricity than in past years. But it would be nice to have some way that I could actually clear the panels so we could make more.

interesting that heating didn’t do anything... But... But what if it were heat tape and right on the frame - on the surface? It seems to me that it’s the lip of the frame, on the edge of the face lowest down, that’s preventing the snow from just sliding off. Why not just run heat tape right there? Or. Ha. Ha ha. Why not just make panels and housings that are flat on top? What the heck is up with the frames that catch things, anyway?

[bcroe]

I already have a sticky on building arrays to minimize snow. Goes something like this.

Mount the panels landscape so the snow does not need to fall/be pushed very far to clear.
There should be at least an 8 inch gap at the bottom edge of every panel so the snow can
easily drop down. Panel ground clearance needs to be enough that panels are not obscured
by cleared snow accumulation. That is 40 inches here at 42 deg L.

Mount panels for easy tilt change, for the snow and non snow seasons. Set tilt for best
energy tilt in summer, vertical for snow rejection. The vertical tilt may benefit from sun
reflected from ground snow.

Use a non conducting snow pusher pole to avoid fatal shock.

Clear panels enough that the sun will penetrate to the dark color, then wait for strong
sun to finish the job. With a vertical tilt, often minimal or no cleaning effort is needed.
All the above imply a ground mount.

Keep in mind that a big piece of the melting problem, is the heat loss of the exposed back
side. Heating tape might melt snow just over the tape, if you can find enough power. I
have already demonstrated applying power directly to the cell elements. With power at
3 times the panel output rating, the snow did NOT melt or slide off. Bruce Roe

[TooMuchSnow]

It was suggested, at work, that I just energize the frames with some DC current for a bit. Like everyone says, the snow will just slide off.

We only really have one accessible section of panels in terms of getting the snow off with a roof rake. And if we don’t take it off it mostly just stays. After the big snowstorm in December we were weeks without generating any electricity. Ouch!

So, actually, I would like suggestions for getting the snow down. The 24’ snow rake clears 18 panels. If I buy another section of pole I can get 9 more cleared. Great. And the other 49 panels (55?)? You know that the physics of having a 40+’ long snow rake aren’t all that good, right? Things are bad enough at 24’ out...

So, work with me! Crazy idea time! How about a rope across each section of panels with pulley systems on the sides so that I can pull and have the rope slide up under the snow? Kind of like the guy throwing his hammer with the rope but mounted and permanent. Might need a huge continuous rope loop and at least 3 pulleys a side of each section of panels but so?

Or there’s gutter heat tape (as opposed to applying DC directly to the frames). The Depot has 200’ for $134. Let’s see... I could do horizontals at the bottoms of panels... That should pay for itself in under a year.

Or, hey, I’m open to other thoughts!

(It was sunny today and I cleared the 18 panels so at least I made 17kwh today. But I could/should have made 4 times that easily. With cleared panels.)

[Mike90250]

......

BTW, looks like you have some terrible shading there - you should add an extra 10' on your poles to get them above the bushes.

I know, dang bushes grow faster than the sun rises ! This was still early AM

[foo1bar]

But you don't have to melt all the snow, just a thin layer and let it all slide off - whoosh

That's true. But not what was being claimed.

And if one of their claims just doesn't hold up to objective computations I get real cynical about the rest of what they say.

BTW, looks like you have some terrible shading there - you should add an extra 10' on your poles to get them above the bushes.

[J.P.M.]

But you don't have to melt all the snow, just a thin layer and let it all slide off - whoosh

My panels cleared after about an hour of sun, only about 2.5 inches of snow
20190205_081100.png

And tomorrow, conditions may well be different. After living in cold/snow for close to a half a century, and observing, I'd say sometimes it does and sometimes it don't, but when it does it, while not unexpected, it often comes abruptly. Other times, it melts some, hits colder surfaces and refreezes. That's how the almighty makes things like ice dams, and another reason why heat tape etc. may not do as well as one might think. Situations are rarely the same twice.

[Mike90250]

So melting 5 pounds takes about 210Wh. (42Wh/pound or 143BTU/pound is the heat of fusion for water).......

But you don't have to melt all the snow, just a thin layer and let it all slide off - whoosh

My panels cleared after about an hour of sun, only about 2.5 inches of snow
20190205_081100.png

[J.P.M.]

So melting 5 pounds takes about 210Wh. (42Wh/pound or 143BTU/pound is the heat of fusion for water).

If it takes about 3 hours, that means 70W per square foot.

A typical residential module is just over 16 square feet - so that means this system would be doing about 1kw per module of heat.

So, yep - looks like a scam to me.

Add to that whatever heat the melt water may transfer to the ambient air over the 3 hours as sensible heat if the ambient air is < 0 C.

The load is also dependent on the dew point of that ambient air for any latent heat for the melt, plus (while not trying to be too p(r)icky), any sublimation directly to vapor by the ice during the period which also adds some latent heat of vaporization to the heating requirements.

It's a B.S. scam by amateurs who may think they are technically proficient but are clueless of what's going on and ignorant of what's required to accomplish a task in a safe and fit for purpose way.

It's asshole antics like this that pushed me back and into a university BSME over 40 years ago to get my own answers. Some things never change.

Caveat Emptor.

[foo1bar]

One more thing that panel warming system has melted 5 lb per square foot of ice on solar panels that are fixed or flexible thin film. It melts in about 3 hours at minus 3 degrees Fahrenheit.

So melting 5 pounds takes about 210Wh. (42Wh/pound or 143BTU/pound is the heat of fusion for water).

If it takes about 3 hours, that means 70W per square foot.

A typical residential module is just over 16 square feet - so that means this system would be doing about 1kw per module of heat.

So, yep - looks like a scam to me.

[J.P.M.]

How do i re-attach my backsheet ?

Best way seems to me to be by not messing with it in the first place by putting stuff over it.

Most of my thinking revolved around how to even get at most of the backside of an array and then how to keep from damaging an array by application and subsequent removal of stuff being stuck to it. Then, there's the performance penalty from increased cell temps. when ice removal is not required with all that's associated with that set of added potential problem scenarios.

I can get under my roof mounted array, but that's with an ~~ 10"-12" or so clearance by design where most are arrays have <=6" clearance or so. Even at 12", I'd have a devil of a time attaching/removing such stuff from my array. Ground mounts might be easier, but the hassle is still probably a PITA, even at 2X/yr. min. on/off and the damage potential and other risks of voided warranties still exist.

Overall, IMO, it's a non solution or worse to the snow/ice removal situation, but simplistic solutions are always tempting and remain fertile ground for con artists and scammers.

This is a B.S. scam.

[bcroe]

I do not see any details on the device, where is it? I ask, why bother to add elements to a panel,
when the energy can be fed into the existing terminals and wiring? My first guess is it would take
6 KW (by his estimate) to clear a string, which I would need to switch from one string after another.
Can not supply enough to do the array in one shot. I used more power than that and failed. Bruce Roe

[Mike90250]

.......... How does one manage to attach and remove such a system from most any array ?
- I'd assume the double faced tape they're referring to (like the double faced carpet tape I've seen and used) has a less than benign effects on surfaces. If so, it'll be the devil to remove, leave a hard to clean up mess and may well void any warranty. All done at least 1X/yr., and with the idea of either working under an array or at least partial array removal to get at what's commonly the inaccessible backside of an array.

This whole thing is a scam.

How do i re-attach my backsheet ?

[J.P.M.]

I have no need for snow removal so I'm not digging deeper into the claims but this poster promoting panel warming is using his real name here and you can easily find him and his company if you Google it. I'm not going to post the company name or link. He of course is out to sell something so abundant caution is advised.

Found it, and it looks more like a scam than ever. Looks to me like some resistance heating elements with what looks like some type of foil wrap covering for the backside of the panel(s) all somehow affixed with what they call double faced tape.
-The device looks like it effectively adds an insulating layer to the backside of any panel.
- So, during times of no icing, the device will cause panels to operate at higher temps. SWAG it would add ~ 5-10 C to temp. difference between ambient air and cell and so raise the cell temp. by the same amount.
- I'd therefore conclude the device is not desirable to have attached to a panel when the panel is not ice/snow covered, and so, to avoid the penalty from unwanted cell temp. elevation, at least biannual attachment/removal will be done, the question becomes: How does one manage to attach and remove such a system from most any array ?
- I'd assume the double faced tape they're referring to (like the double faced carpet tape I've seen and used) has a less than benign effects on surfaces. If so, it'll be the devil to remove, leave a hard to clean up mess and may well void any warranty. All done at least 1X/yr., and with the idea of either working under an array or at least partial array removal to get at what's commonly the inaccessible backside of an array.

This whole thing is a scam.

[azdave]

Well, one more thing on your free advertising /scam odyssey: I suppose you can supply some independent testing to substantiate that ? Until then, and without a lot more info about how this stuff doesn't/won't/can't void claims,it's still a B.S. scam.

I have no need for snow removal so I'm not digging deeper into the claims but this poster promoting panel warming is using his real name here and you can easily find him and his company if you Google it. I'm not going to post the company name or link. He of course is out to sell something so abundant caution is advised.