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

[inetdog]

Quite a few off grid folks in snow country just tilt their panels in the winter to a high enough angle that the snow does not build up and slides off every day.
Others use a snow rake from the ground.
It is interesting to look at the break even point between energy used to heat the panels versus the energy gained by uncovering them if the weather is bad. Certainly seems to need manual control.

[osirisstevens]

Hello to everyone that needs snow melted from their solar panels during the winter months.
There is a company in Colorado that sells kits for snowmelt, [redacted]. They have a patented partner with an electro plastic that uses carbon nanoparticles to heat the solar panels.

It can be installed on any size solar panel and can adhere to a solar panel in 10 seconds. They are not a thin film heat tape/copper wire, heat tape of any kind, gas heated in any way, magnetically heated through four magnets that rub each other to create heat, heated hot water or liquid jell boiled in any way.

Their website is [redacted] and they do much more than just solar panel heating systems. They have micro-inverters that work with reactive power on demand 24 hours a day to give you a stronger power output from your solar array. They have racking systems, solar panels, carports, solar walkways, water creation from humidity, greenhouses, solar panels for greenhouses that grow food 40% faster than a regular greenhouse and use 5-70% less water for that growth, mobile greenhouses, and have three different types of DERM systems.

Mod Note: This is on the border between supplying information and advertising. I have made the URL information unclickable as a first step while we decide whether to allow the post or not.
ModNote2: The poster is a principal of the company involved. That makes it an attempt to get free advertising. Company link removed completely.

[ionized]

I was thinking of a similar Rube Goldberg solution, but with no hot air. Just string up some PVC to some points near the edges of the panels and connect them to a leaf blower. You only have to clear part of a panel to really accelerate the melting.

[Calgirl]

Snowed-in Panel Remedy

How about some foam insulated PVC/ABS with holes to blow hot air. Run PVC down to a convenient access point where you have a blower set up to blow hot air.

Sugar will work, though not as well. You're essentially trying to add a substance to the snow that will dissolve in water, thereby throwing off the balance between freezing and melting. ANYTHING that dissolves in water will help do this; salt works best because it's really cheap.

[heartlander66]

Silicone-Rain-x

Polish when surface temp.= 65*+.

Hi everyone, I hope you guys don't mind me registering to ask some questions...

To give you a little background - I'm off the grid in north-central CO full time. I have a 2800 rated watt PV array running through a trace and a couple of outbacks, charging a 16 battery bank made up of Rolls 530 amp hour lead acid batteries. As you'd probably guess, the system runs great.

Only issue we have is in December when the temp drops to about -20 overnight and hovers around -5 during the day. When it's that cold, even 2" of snow on the solar panels isn't going anywhere, even in bright sunshine at 9600'.

Since I have a bit of a panel access issue, I've been kicking around various ideas about how to deal with the snow besides climbing up and brooming it off. One thing that came to mind was that since the panels are so thin in most places, I might be able to run heat tape along the back of the panels with the idea that I could even run the tape off my generator. I'm concerned that this approach will either generate too much heat and damage the panels, or not enough heat and will have no effect on the snow load.

Anyone here play around with this idea at all?

Thanks guys!

[dave]

I would just buy a roof rake - the shaft on it is 20 feet long and if you need longer then buy two. The plastic scoop on the front will not damage the solar panels and they are easy to push to the top of the array. As stated - once the snow is cleared off a bit of the panel it will evaporate quite quickly = Yes I wish it would just slide off of a 50 plus degree tilt at -20 C. I have thought of a black curtain on the front side to insolate and heat the snow but figure this may be to complicated so will look into this before I reach 85

[SpaceOddacy]

Ah, but you don't need to melt all the snow, just a very thin layer to allow the rest to slide off, like butter off a hot knife

this.

Butter and knives go together like bacon and turkey!
You only need to create a small layer of melted snow to 'lubricate' the rest so the angle and gravity takes care of the rest.

[Mike90250]

For an idea of how much energy is required to melt snow please see the following link - http://withouthotair.blogspot.com/20...alination.html

In short - Quote - The latent heat of melting of ice is 6 kJ/mol, or 333 kJ per kg, a quantity I have never been able to memorise... until now! Using the same trick as above, we can convert this into an equivalent temperature rise, by dividing by the heat capacity. The answer is "the latent heat of melting of ice 'is' 80 degrees C".
I don't think I'll forget that number! It really brings home why mountaineers spend so much time melting snow. The energy to melt the snow is roughly the same as the energy to bring the melted snow up to boiling point!

Ah, but you don't need to melt all the snow, just a very thin layer to allow the rest to slide off, like butter off a hot knife

[SpaceOddacy]

If you're panels are off of the roof a few inches why not block off two of the sides and 'seal' them to the roof temporarily for winter and blow warm\hot air under them this way the panels heat up in a more natural way?

[russ]

For an idea of how much energy is required to melt snow please see the following link - http://withouthotair.blogspot.com/20...alination.html

In short - Quote - The latent heat of melting of ice is 6 kJ/mol, or 333 kJ per kg, a quantity I have never been able to memorise... until now! Using the same trick as above, we can convert this into an equivalent temperature rise, by dividing by the heat capacity. The answer is "the latent heat of melting of ice 'is' 80 degrees C".
I don't think I'll forget that number! It really brings home why mountaineers spend so much time melting snow. The energy to melt the snow is roughly the same as the energy to bring the melted snow up to boiling point!

[Mike90250]

I saw on you tub a guy selling Midnite controllers and he talked about with his controller you could thru the internet tell your panels to melt the snow...

Yep, take out the blocking diode, and at nighttime, your batteries discharge thru the panels, making them warm.

But, not awfully effective, and it drains your batteries.

[russ]

Hi Ernie - No doubt it can be done but just not efficiently.

Russ

[Eherst98]

Melting Snow off solar panels

I saw on you tub a guy selling Midnite controllers and he talked about with his controller you could thru the internet tell your panels to melt the snow...
Just a note .. interesting.. maybe the Midnite people know how too....
Something about working in reverse..?
Ernie

[jmf]

Thanks for the replies!

I haven't looked into an eve or replacing the racks, only because of the difficulty of the project. The panels are on the drop side of a modified a-frame, about 45' off the ground. At some point in the future, I'll need to replace the roof on the house, and I'll be looking at those options at that time. I'm hoping to get them off the roof all together, but we're on a north facing ridge... Being up on the roof gives us excellent sun. Far better actually than most of our neighbors on the south facing slope. Even in december/january, we're making power by 9am and then do so until sun set. But 10' off the ground, the sun coverage is lousy in most places, except for one spot that's about 600' from the house. So, it's a bit of a wash in the end. I haven't gotten the walkway built yet, but we're having a nice indian summer here and it could still happen. This time last year, we had 3' of snow in two days...