Hot water radiant loop under array to prevent ice/snow buildup?

[Mr4btTahoe]

Hello alls

So my wife and I are strongly considering purchasing an outdoor gasification boiler to heat our home, my shop, and our domestic hot water... reducing our electrical usage during the lower power production part of the year.

I was outside yesterday and staring at my array on the roof of my shop which is currently covered in 6" of snow and 1/2" of ice under that. I dread this time of year.. its either climb up on the ladder in the ice and snow to clean the panels off... or live with the lack of production for a week or more at a time.

We have a ~10kw array on the roof of my 24x48 pole barn. Metal roof with IronRidge racking but fairly low pitch (4/12).

Then a thought popped into my head. Many use their outdoor boilers for in floor radiant heat using pex tubing. Could one run a loop of pex (valved for isolation) between the array and the metal roof? Block off the top and sides to hold in heat and only open the valves on the loop when snow or ice is forecast. I think it would provide enough heat to keep the panels above freezing melting any ice or snow that landed on them but not hot enough to cause issues.

Wouldn't take much in materials as there will already be a heat exchanger in the shop. Would take a bit of work fishing the pex under the array without pulling panels but I think it's doable. Obviously the boiler would be burning through a good bit of wood while that loop is active so there is that to consider.

I'm not aware of any regulation or code that would prevent such an installation.

Thoughts? Would it work?

The boiler will likely be filled with a glycol mix so freezing wont be an issue.

[peakbagger]

I have thought the same. My approach would be to only use it to encourage melting when the conditions are right. Years ago our family home had ice damming issues. we installed electric heating cables on the lower edge of the roof, the gutters and the downspout. The standard recommendation at the time was leave them on 24/7, but we found that just turning them on when the sun comes up for a few hours would loosen the snow on the roof and expose a strip of the darker asphalt shingles under the snow which would absorb more sunlght. My pure guess is if you run a loop at the lower edges of the panels that it might expose enough panel to get the melt going. In my experience I can get to the lower 8" of my 2nd floor array with a roof rake and if I can expose just a strip of panel, the sun will start heating up the darker surface and the snow will slowly melt its way up the panel. The problem I run into is I have two rows of portrait panels on top of each other. The gap between the panels acts as thermal break and the melt up stops at the top of the lower panel. Therefore you would need to do an additional strip at each row of panels.

My guess is this may invalidate any panel longevity guarantee although they would need to find out to know it. I would not try to heat an air space, I would rig up something like a length of the tubing in the radiant heat reflectors used under floors. It would probably need to be spring loaded clips on each end to hold it up against the back of the panel.

Its an experiment that many would be interested in.

A unsolicited and completely biased opinion is outdoor wood boilers of any type are miserable devices and banned outright in many states or limited in others. They may come with great emissions claims from the dealers selling them but there is a fundamental problem that is when there is no heating demand, the boiler has to smoulder with its air cut off until there is heat demand. They do work well in very cold weather but they suck in shoulder seasons and by design they tend to become a low level significant source of emissions when they are smouldering. They burn a lot more wood than an indoor boiler design with thermal storage that get fired at full load every few days to heat up the storage tank. The house is then heated off the storage tank. They are a lot more efficient. If you want to put one of these outdoors in a shed you can do that but its heck of lot easier on a nasty night to go down in the basement and feed it a few times. This is link to very good course on high efficiency biomass heating that NY state pays for. Its worth watching https://www.heatspring.com/courses/h...red-by-nyserda

The big tradeoff is indoor wood boilers (or any EPA certified boiler) forces you to use dry properly seasoned wood. Use wet wood and they just will not burn well. OWBs even the fancy new ones are usually easy to rig them to burn damp poorly seasoned wood.Sure they may burn the damp wood but they need a lot more and the pollute the area around them.

[Mr4btTahoe]

As it stands... we already heat with wood in an old non-epa rated stove. We do have a 6 head mini split system that does a decent job but we like heating with wood.

The boiler we are looking at is an EPA 2020 "step 2" certified gasifier. I'm sure it will still put out a bit of smoke when smoldering... but our wood stove does as well so not much trade off there. The ones we are looking at are the Central Boiler Classic Edge 560 Titanium HDX. It's got an EPA rating of over 90% efficiency which I'm sure is a lot better than our stove from the '80s. Even the non-epa rated boilers are legal in my state as far as I know as I can still buy them. They are much cheaper but I don't want the drastic increase in wood use. Based on what I've read and seen, it likely wont use much more wood than my current stove... will eliminate the mess in the house... will heat our water and my shop. There are trade-offs for sure.. but I think it's worth it.

I live on 10 wooded acres and since we heat with wood, we typically keep 2 seasons stacked and ready so well seasoned wood isn't an issue. We also have a bunch of trees that will be coming down in the near future so fueling this thing for the next 5+ years wont be an issue with what we already have ready to go. I also buy wood from a local pallet manufacturer. They build HD pallets and use 4x6 main runners. They pile up their cutoffs (which are kiln dried hardwoods) and sell them as firewood. We buy it by the trailer for $30/load.

I think I'll attempt it unless someone points out a major flaw in my thinking.

The heating loop will likely be on the roof surface not in direct contact with the panels or racking so it shouldn't affect the warranty of either.

It'll certainly be a big science experiment. Wont cost much.. few hundred feet of pex and a couple valves/fittings. It'll take a good bit of effort to get it in place but should be doable.

The water coming out of the boiler will be between 160-180F. I'd say a few runs of pex would keep the roof surface and panels above freezing pretty easily.

If I decide to try it, I'll keep this post updated.

Any other thoughts?

[J.P.M.]

Summed up: A bad idea for more reasons than I care to write about.

A bit like the ideas and schemes folks come up with to heat water by snagging the excess energy PV panels normally reject as thermal energy, only in reverse and probably more trouble prone and impractical if that's possible.

There's a lot you don't know, and what you don't know can hurt you. This is what I call a "You could just..." idea - as in "You could just do this and Voila !... problem solved". Ideas such as this seem good in theory, then reality and the details you didn't know existed happens and things come top a bad end when reality happens, you wind up with only your best intentions in you hand and things come to a bad end when details which you know little about conspire to give you a bad outcome.

If nothing else, the value of the the energy you might gain from less snow on an array will be much less than the cost of what you want to do. Then there's all the maintenance...

Feel free to experiment all you want, but if you knew what I think I might know by virtue of formal education, and more importantly, experience, the idea would not have any appeal to you, much less credence.

[Mr4btTahoe]

Summed up: A bad idea for more reasons than I care to write about.

A bit like the ideas and schemes folks come up with to heat water by snagging the excess energy PV panels normally reject as thermal energy, only in reverse and probably more trouble prone and impractical if that's possible.

There's a lot you don't know, and what you don't know can hurt you. This is what I call a "You could just..." idea - as in "You could just do this and Voila !... problem solved". Ideas such as this seem good in theory, then reality and the details you didn't know existed happens and things come top a bad end when reality happens, you wind up with only your best intentions in you hand and things come to a bad end when details which you know little about conspire to give you a bad outcome.

If nothing else, the value of the the energy you might gain from less snow on an array will be much less than the cost of what you want to do. Then there's all the maintenance...

Feel free to experiment all you want, but if you knew what I think I might know by virtue of formal education, and more importantly, experience, the idea would not have any appeal to you, much less credence.

I'm gonna have to pry at your response a bit... maybe get you to give some reasons?

You tell me not to do it.. and claim that your reasoning is your education and experience.. but wont tell me why it's a bad idea.

You do claim cost as a factor.

Cost of what I want to do: ~$75 in materials. (300' roll of pex tubing, some isolation clamps to support the tubing and 2 ball valves)

Currently.. my system isn't producing any power and hasn't been for over a week. Wont produce any power til mid week next week and we've had quite a bit of sun. Air temps are too low to let the 6" of snow melt.

You also claimed maintenance. What maintenance is there in a 300' piece of plastic tubing and 2 valves filled with glycol/water mix? It's under the array so can't be damaged... its above an insulated metal roof so not going to be putting much heat into the building.. most heat would be reflected or radiated back to the array. The loop would only be active during ice/snow events so not much energy loss from the boiler. Even if it were to spring a leak or fail in some way, everything near the loop is water proof and exposed to rain, ice, and snow already so no real risk of damage to anything.

There will already be a hot water line ran into the shop from the boiler for the heat exchanger in the shop. The lines will already be there as will the pump and such to make it work.

So I guess I'm drawing a blank on what exactly would be the negatives. I know that it would certainly beat me climbing up on the roof every time it snows chancing a fall to clear the snow manually.

So do you care to explain why it's such a bad idea or why it won't work?

I'm not talking about heating the panels electrically. This is a wood fired outdoor boiler. Hot water will already be plumbed to the shop in which the array is on so no added work there. Not using electricity to do the heating and the extra load on the boiler will actually help it burn cleaner.

What am I missing?

[Mike90250]

Why not ?

Melting a chunk might create a ice dam problem lower down the roof, when water running down, hits snow

PEX is normally not UV resistant. even in shade from panels, enough UV can get to it to ruin it. Some PEX has UV rating, but I don't know how good it would be,

I would make several heating sections, to clear just 1 area before the next, instead of trying to clear the whole thing at once.

heating sequence - start at top rows, then down a row, or start at bottom and go up. Which melts better and causes less "damming" ?

[J.P.M.]

What am I missing?

A lot.

I'm not ragging on you, nor am I trying to duck out, but without seeing your plans and a lot of other information, it's not possible for me to give you a detailed explanation as to why what you have in mind is not viable or even feasible. Even if I did, it wouldn't be here as it would take more time and room than this venue will allow. For one thing, if you think $75 and 300 ft. of pex will solve your problem, that tells me you are out of your league. Don't waste your time/money/effort.

Q: Did you consider the necessity of snow removal before you purchased the array ?

Also, do you see any other array(s) either in your neighborhood or anywhere else that have array heating schemes ? I'm pretty sure such a system would be commercially available if it were feasible. I've seen or heard of none.

If you provide a heat source under the array by laying the pex on the roof, you better find a way to tightly seal and insulate the area perimeter, as well as a way to remove and replace the perimeter in the spring and fall if you don't want to do little more than heat the outdoors in the winter and reduce array performance in the summer from excess heat in the array from poor/no ventilation underneath. You also better find a way to close the gaps between panels such as they commonly exist. Otherwise you'll be trying to keep heat in a sieve.

Then, as Mike writes, and if you do manage to melt some snow/ice, there's the problem of ice dams.

Without some calcs and at least dimensional sketches, I couldn't hazard a guess as to the heat loss from such an under the array enclosure as you seem to propose. Have you done such an analysis ? I'd guess not and suggest that getting such a space warm enough to melt snow/ice on an array is going to take a lot more than 300 ft. of pex that has ~ 25 ft.^2 of radiant heat transfer surface to melt snow/ice from what's probably ~ 650-700 ft.^2 of panels with ~ 1" or so gaps between the rows or columns. For one thing, you'll probably wind up supplying more heat to the pole barn roof and the barn itself than the array. Any air under the array that does pick up any heat will quickly leave through the gaps between panels. Most of any heat transfer from the pex to the panels will be via thermal radiation. Convective heat transfer will be minimal between any heated air and the backside of the panels. Conduction heat transfer will be essentially non existent.

That's a very sketchy description of just a few of many things of a long list of things to think about.

Look, I like solar energy and I don't have a bone to pick with you or an agenda. Solar energy was the initial impetus behind why l changed careers and became a mechanical engineer ~ 45 years ago. I want solar projects to be safe and successful and make sense. IMO, what you describe meets none of those criteria, but it ain't my array, money, life, or problem.

If I understand correctly what you have in mind, it will take a lot more time, toil, design, money and maintenance than you have any clue about, and it simply will not work.

But, knock yourself out.

Welcome to the forum of few(er) illusions,

[peakbagger]

Ice damming is not an issue on my roof array in snow zone. I have ice and water shield from the bottom of roof to the top so water inst getting into the roof. I also have full width soffits vents, proper vents, gable end vents in addition to a ridge vent that is incidentally worthless in high snow environment when they get covered with snow. Most importantly I do not have gutters. I do have slotted rain deflectors that can be issue in winter for icicles but not a ice damming issue. The bottom of the array is about a foot up from the lower edge of the roof. My guess is if there was an ice damming issue before it would be no better or worse with limited solar panel heating on a well insulated home. In my experience ice damming is just a sign of a contractor that did not understand the basics. Folks think a warm attic for some reason is good thing but in the case of ice damming its the worst thing. There are multiple videos out there, some by a group called Building Sciences on the web that explain how to build so ice damming is not an issue by proper ventilation. I have helped diagnose and fix more than few ice damming issues over the years and once the fundamentals are understood, its not rocket science although modern architecture with lots of gables definitely add a lot of challenges. Full coverage ice and water shield is pretty well standard on all commercial roofs in my area and it covers lots of sins so most of the issues are with residential homes. The first thing I ask when I am asked to look at a problem is for the owner to put a thermometer up in the attic and tell me how how much warmer it is than the outdoors at different times of the day. If the inside is appreciably warmer during the day then its a candidate for ice damming. The next tip is go up in the attic on a sunny day and see if I can see a clear path down to the soffits, I should be able to see light but the majority of the time I see insulation batts stuffed up against the roof. Pull the batts, slide some proper vents into the spaceup against the roof and the slide the batts back in place and the ice damming rapidly is not an issue.

As mentioned, the other big issue is the popularity of ridge vents integrated into the roofing system. Its may a be great idea in summer but in winter in a moderate to heavy snow zone those vents get sealed over with snow and may not reappear for months. I have dug out ridge vents in the past and what I usually find is a small gap and then a layer of frozen snow. sealing it off, Inevitably the attic will be warm on a sunny winter day. Once I clear the ridge vent off the temps in the attic drop until it gets covered with the next snow storm. Thus the strong suggestion is to go with gable end vents properly sized. I see lots of commentary that mixing gable end vents with ridge vents is self defeating and impacting the "draw" up through the soffit vents but if the soffit vents are correctly sized (frequently they are undersized or blocked) I have not seen it as an issue. One down side to gable end vents is no matter how well they are sealed with louvers and screens, in blizzard type events fine snow seems to fine its way into the vents and into the attic where it lands on top of the insulation and then melts down through the insulation and make a wet spot on the ceiling eventually. Good carpenters build a tray attached to the bottom lip of the went lined with tin (these days poly) inside the attic so if that rare occasion happens it lands in the tray and then sublimates directly or thaws and evaporates. Many homeowners do not understand what they do and I have seem some homes where there were traces of them but the homeowner has taken them out.

So back to heating PV panels. As I stated in my opinion conductive heat transfer directly to the back of the panel using radiant strips at the lower edge of the panels is the way to go. Sure you can try to heat the entire air space under the panels to keep the melted 24/7 but my approach is just to kickstart natural melting.

One definite hassle is to get a water tight roof penetration for the pex lines. Those roof penetrations were a major PITA and source of call backs for solar hot water systems years ago as they are for current solar installers. Many installers just drilled a hole through the roof and gooped them up, My long term approach was a standard roof boot over an oversized PVC sch40 pipe.I then slld rubatex insulation up inside the PVC and then my 3/4" copper line to the panel inside it. Mine are still tight after 25 years but it definitely took some research to figure out how to do them right. My method would be difficult to implement under a typical panel. I could guess on a solution by using a soladeck type solution converted for moving water, with two elbows in the box where the din rail normally is and the tubing running out the lower edge where the conduits normally run.It would be custom for sure. Do it wrong and you will kick yourself when the water leaks starts but I think it may be workable. With respect to UV degradation of PEX, if you put the modified soladeck under the panel its got very good shading. You need to insulate the PEX anyhow so just insulate with flexible closed cell foam and wrap it with an outdoor rated 3M tape product used to wrap electrical cables. It looks like good old super 33 electrical tape but comes in various widths. I have seen 6" wide and it seems to last for years if applied properly wrapping up from a low point to a high point so water flows down over a seam instead of into a seam..I think an important aspect is to keep the loop temps low, the lower the better, Just get the surface up over freezing. If you are using a conduction plate my guess is 100F in ?.

[Mr4btTahoe]

A lot.

I'm not ragging on you, nor am I trying to duck out, but without seeing your plans and a lot of other information, it's not possible for me to give you a detailed explanation as to why what you have in mind is not viable or even feasible. Even if I did, it wouldn't be here as it would take more time and room than this venue will allow. For one thing, if you think $75 and 300 ft. of pex will solve your problem, that tells me you are out of your league. Don't waste your time/money/effort.

Q: Did you consider the necessity of snow removal before you purchased the array ?

Also, do you see any other array(s) either in your neighborhood or anywhere else that have array heating schemes ? I'm pretty sure such a system would be commercially available if it were feasible. I've seen or heard of none.

If you provide a heat source under the array by laying the pex on the roof, you better find a way to tightly seal and insulate the area perimeter, as well as a way to remove and replace the perimeter in the spring and fall if you don't want to do little more than heat the outdoors in the winter and reduce array performance in the summer from excess heat in the array from poor/no ventilation underneath. You also better find a way to close the gaps between panels such as they commonly exist. Otherwise you'll be trying to keep heat in a sieve.

Then, as Mike writes, and if you do manage to melt some snow/ice, there's the problem of ice dams.

Without some calcs and at least dimensional sketches, I couldn't hazard a guess as to the heat loss from such an under the array enclosure as you seem to propose. Have you done such an analysis ? I'd guess not and suggest that getting such a space warm enough to melt snow/ice on an array is going to take a lot more than 300 ft. of pex that has ~ 25 ft.^2 of radiant heat transfer surface to melt snow/ice from what's probably ~ 650-700 ft.^2 of panels with ~ 1" or so gaps between the rows or columns. For one thing, you'll probably wind up supplying more heat to the pole barn roof and the barn itself than the array. Any air under the array that does pick up any heat will quickly leave through the gaps between panels. Most of any heat transfer from the pex to the panels will be via thermal radiation. Convective heat transfer will be minimal between any heated air and the backside of the panels. Conduction heat transfer will be essentially non existent.

That's a very sketchy description of just a few of many things of a long list of things to think about.

Look, I like solar energy and I don't have a bone to pick with you or an agenda. Solar energy was the initial impetus behind why l changed careers and became a mechanical engineer ~ 45 years ago. I want solar projects to be safe and successful and make sense. IMO, what you describe meets none of those criteria, but it ain't my array, money, life, or problem.

If I understand correctly what you have in mind, it will take a lot more time, toil, design, money and maintenance than you have any clue about, and it simply will not work.

But, knock yourself out.

Welcome to the forum of few(er) illusions,

Yes I considered snow removal and cleaning.

As for other solar arrays in my area... not many and none of them have outdoor boilers.

You keep saying melt snow and such. I don't want to melt snow that is already on the array. I want to open the loop when snow is forecast meaning the panels would potentially be above freezing before the snow or ice falls preventing the sticking of ice/snow. Same principal of using a 75w light bulb in a well house to prevent the pump from freezing. It doesn't take much heat to PREVENT freezing. Melting off 8" of snow after the fact wouldn't be possible more than likely.

The array is 525 sq ft. with ~4" between the roof surface and the bottom of the panels. Blocking off the underside of the array wont be overly hard using 1.5" rigid foam that could be placed near the end of fall and removed early spring. Using the IronRidge racking, it maintains a 1/4" gap between panels. Heat loss between those gaps would warm the panel edges. The metal roof of the shop is insulated so any heat transferred to the metal roofing would then just transfer to the air above it.

Ice dams aren't an issue. The array literally covers the southern face of the roof. The panels are even with the roof edge and drops into the gutter. Any melt drips into the gutters.

A 300' tube filled with 180F water trapped in a 4" space... you're saying that wont increase the air temperature of that space 20F? We're talking ~15 cu. ft. of air space under the array. Could even add some transfer plates to the pex like what is used to increase heat transfer when used between floor joists.

I'm not an engineer... but I've personally seen a light bulb keep a larger space from dropping below freezing with gaps between planks and the door larger than what is between the panels. Can you explain why it wouldn't work the same way?

Your argument that "you don't see that anywhere". Right. In order for most to do what I'm wanting to do, would require them to use a water heater which the energy spent heating the water would be a wash. It would cost more to heat the water than the array would produce over the time period the array is cleared vs leaving the snow on the array. Solar energy isn't main stream by any means. Outdoor wood boilers are even less prevalent... so no.. haven't seen anyone do it. Have heard of people talking about it.

Melting ice and snow is vastly different from preventing ice and snow from sticking as it falls which is what I'd prefer to do. I don't think it's feasible to melt off a large snow fall or ice once already formed.

I will say that heated driveways are common in my area. They use radiant hot water in tubing to melt off ice and snow.

[J.P.M.]

Yes I considered snow removal and cleaning.

As for other solar arrays in my area... not many and none of them have outdoor boilers.

You keep saying melt snow and such. I don't want to melt snow that is already on the array. I want to open the loop when snow is forecast meaning the panels would potentially be above freezing before the snow or ice falls preventing the sticking of ice/snow. Same principal of using a 75w light bulb in a well house to prevent the pump from freezing. It doesn't take much heat to PREVENT freezing. Melting off 8" of snow after the fact wouldn't be possible more than likely.

The array is 525 sq ft. with ~4" between the roof surface and the bottom of the panels. Blocking off the underside of the array wont be overly hard using 1.5" rigid foam that could be placed near the end of fall and removed early spring. Using the IronRidge racking, it maintains a 1/4" gap between panels. Heat loss between those gaps would warm the panel edges. The metal roof of the shop is insulated so any heat transferred to the metal roofing would then just transfer to the air above it.

Ice dams aren't an issue. The array literally covers the southern face of the roof. The panels are even with the roof edge and drops into the gutter. Any melt drips into the gutters.

A 300' tube filled with 180F water trapped in a 4" space... you're saying that wont increase the air temperature of that space 20F? We're talking ~15 cu. ft. of air space under the array. Could even add some transfer plates to the pex like what is used to increase heat transfer when used between floor joists.

I'm not an engineer... but I've personally seen a light bulb keep a larger space from dropping below freezing with gaps between planks and the door larger than what is between the panels. Can you explain why it wouldn't work the same way?

Your argument that "you don't see that anywhere". Right. In order for most to do what I'm wanting to do, would require them to use a water heater which the energy spent heating the water would be a wash. It would cost more to heat the water than the array would produce over the time period the array is cleared vs leaving the snow on the array. Solar energy isn't main stream by any means. Outdoor wood boilers are even less prevalent... so no.. haven't seen anyone do it. Have heard of people talking about it.

Melting ice and snow is vastly different from preventing ice and snow from sticking as it falls which is what I'd prefer to do. I don't think it's feasible to melt off a large snow fall or ice once already formed.

I will say that heated driveways are common in my area. They use radiant hot water in tubing to melt off ice and snow.

Rooftop PV arrays weren't and are not currently designed with consideration for active, or any for that matter any snow removal by heating other than that provided by solar energy and as your situation and a lot of others show, that doesn't work. There might be a pretty good size niche market ripe for development.

While I encourage your enthusiasm, my opinion as a retired P.E. is that without a lot of consideration for things you are ignorant about, what you want to do won't work as effectively as you seem to want to talk yourself into - if at all. You speak anecdotally about situations that you think parallel or are close to what you want to do. That doesn't seem a good knowledge base to start from. If you knew some of what I think I might know after an engineering career involved mostly with getting thermal energy from point A to point B safely, efficiently and in cost effective and workable ways (or slowing down that rate of transfer) you might not be so convinced of the workability of your idea. Were you are now doesn't seem like a good knowledge base to start from.

I don't have a hardon for you or your idea. I just don't like to see folks waste time, toil or treasure on stuff I'm pretty sure will come to a bad end. But NOMB.

I'd be interested in hearing how it works out for you. I'd also suggest a look at a website called "builditsolar.com". Sort of a mixed bag of DIY stuff. I don't know if there's anything on that site with respect to melting ice/snow off an array, but here's a lot there with some of the content pretty specialized. Some of its content is near genius. Some of it is harebrained and dangerous - either long term or short term. But it's a decent source for ideas as long as you keep safety in the forefront of your mind.

Good luck.

[Mr4btTahoe]

Rooftop PV arrays weren't and are not currently designed with consideration for active, or any for that matter any snow removal by heating other than that provided by solar energy and as your situation and a lot of others show, that doesn't work. There might be a pretty good size niche market ripe for development.

While I encourage your enthusiasm, my opinion as a retired P.E. is that without a lot of consideration for things you are ignorant about, what you want to do won't work as effectively as you seem to want to talk yourself into - if at all. You speak anecdotally about situations that you think parallel or are close to what you want to do. That doesn't seem a good knowledge base to start from. If you knew some of what I think I might know after an engineering career involved mostly with getting thermal energy from point A to point B safely, efficiently and in cost effective and workable ways (or slowing down that rate of transfer) you might not be so convinced of the workability of your idea. Were you are now doesn't seem like a good knowledge base to start from.

I don't have a hardon for you or your idea. I just don't like to see folks waste time, toil or treasure on stuff I'm pretty sure will come to a bad end. But NOMB.

I'd be interested in hearing how it works out for you. I'd also suggest a look at a website called "builditsolar.com". Sort of a mixed bag of DIY stuff. I don't know if there's anything on that site with respect to melting ice/snow off an array, but here's a lot there with some of the content pretty specialized. Some of its content is near genius. Some of it is harebrained and dangerous - either long term or short term. But it's a decent source for ideas as long as you keep safety in the forefront of your mind.

Good luck.

How about a different approach.

I'm seeing many suggestions for snow removal saying to hose them off with water once the temperature is above freezing.

What about using warmed water? Again... water would be heated with the outdoor boiler so no real waste of energy. Installation could be as simple as a single run of cpvc across the top of the array that is insulated and perforated. Spray the panels off in the early morning with ~100F water or so and then shut it off and drain the line to prevent freezing.

Basically.. I'm just tossing ideas around as I'll have an abundance of heat energy at my disposal. If I can utilize it to solve a problem I have.. then I would love to do so.

I also don't mind experimenting with things.

The likelihood of the water freezing before running off the panels is low.

I'm open to other off the wall ideas but would like to try the ones that are most likely to be effective. I don't mind the effort.

[Mr4btTahoe]

Or maybe I should just setup scaffolding by the shop every fall so I can clean them off manually without being on a ladder. My goal is to maximize production and don't mind tinkering.

[Mike90250]

I'd only wash snow off with water no warmer than 40F, or risk thermal cracking the panels from shock.

[peakbagger]

I just wait a couple of days, set up my extension ladder and rake them off with a snow rake. I have 3 different brands of panels and none of them seem to exhibit any surface deterioration using a plastic snow rake.

[bcroe]

The heat required to get snow off panels would be considerable. In an
earlier thread I set up a panel at a steep angle, party covered with snow,
typical IL winter weather. Electric power was applied to the panel for
many minutes, gradually increased to 3 times the panel rated max output.
For all this, the snow was unaffected. Of course, the heat was being
dissipated over both sides of the surface, not accumulated. My conclusion,
electric defrost was not going to work.

OK, running a hot tube across the panel might affect the nearest area. The
panel is not going to efficiently conduct that heat over its full surface. A
complete seal and heating of the underside might work better, is that even
doable?

Here the approach has been to arrange panels to minimize snow accumulation,
and so that they can easily be cleared. First step is get them near vertical for
the snow season. Ground mount only 2 high in landscape, so the top can be
easily reached. Leave an 8 inch gap between upper and lower panels so snow
does not need to be moved very far, and so the pile in front of the panels does
not get so big. Mount panels high enough to stay clear of ground snow
accumulation. This actually works, snow clearing efforts range minimal to zero,
depending on the storm. See the sticky Snow Tolerant PV Mounting
Started by bcroe, 04-17-2018

Here is a picture from this week, note snow on 2 different array setups. Bruce Roe

Feb21ice.JPG