Snow removal

[bcroe]

I'll be curious to know if anyone can think of a good deicer for this application. Something which:

• Isn't corrosive
• Doesn't kill the landscaping
• Is OK to let run into ponds, streams, and storm sewers
• Doesn't degrade roofing material or sealants
• Is an effective deicer

The best candidates I could think of are sugar water (which turns out to be a fairly poor deicer) and ethanol (which I'm afraid might do unhelpful things to asphalt shingles). Many other common deicers are easy to rule out as corrosive (salt) or bad for plants or aquatic animals (glycols).

I wouldn't try anything that isn't a great insulator. That may eliminate most. I spilled a bit of
sugar water (Coke) on an old keyboard, and I finally had to throw it out. Think I'll just be waiting
for a better combination of temp & sun.

I believe your panels are larger than any of mine. Bruce Roe

[SunEagle]

I wouldn't try anything that isn't a great insulator. That may eliminate most. I spilled a bit of
sugar water (Coke) on an old keyboard, and I finally had to throw it out. Think I'll just be waiting
for a better combination of temp & sun.

I believe your panels are larger than any of mine. Bruce Roe

There is a lot more to Coke then just sugar water. I would use a 16 oz bottle to open a plugged sink drain. Cleaned out the food and other junk that stopped it up. Definitely some caustic in that stuff.

I wish there was a simple fluid that would keep the snow from sticking yet not harm the panel surface. Must make it hard to have solar in areas which gets lots of snow.

Hey maybe if the panels could be vibrated to some specific frequency that the snow wouldn't be able to stick. Sorry just thinking out of the box for a moment.

[Mike90250]

pump warm (not hot) water to a manifold tube at the top of the array ?

[bcroe]

pump warm (not hot) water to a manifold tube at the top of the array ?

That's a joke, right? How about this portable plastic green house, just set it over panels
and wait. Lets see, 130' long, 12' high and deep, how to lift it and store it? Bruce

[PVinstall]

pump warm (not hot) water to a manifold tube at the top of the array ?

oops

[peakbagger]

If someone wanted to use fluid, I would suggest commercial deicing fluid used on airplanes. There a lot of similarities with solar panels. I expect if one could apply it at the top of the panels, it might break the bond between the panel and the snow which would accelerate the snow sliding off.

Generally the approach used in northern climates is mount the panels vertical and don't worry about snow. PV watts does take into account increased insolation from snow so the performance hit is not as bad as a vertical panel would model. Of course at 46 degrees latitude, vertical panels would be significantly impacted during the summer.

My wall mount array acts like an awning over an angle bay window. In the winter with a low sun angle the sun is low enough that the panels don't block it from entering the building but in the summer the windows are entirely shaded. It has made a noticeable difference in the temperature in the room with the window in summer to the point where even if the panels are not running I would probably leave them up. My set up was not designed for style, built out of unistrut and was added onto the house after it was built but I expect a similar concept could be cleaned up and integrated into the design of a new structure. I even have envisioned a vertical tracking component but expect the cost would far exceed the increased power gain. Of course this system is 10 years old and I seem to remember paying $6.50 per watts for the panels. Given the low cost for panels these days I expect having a summer roof array and a winter vertical array might start to make sense.

[northerner]

There are three basic approaches to removing snow and ice from Solar Panel: mechanical, chemical, and thermal. It's not necessary to completely clean the solar panels, just get enough snow off so the dark surface can start absorbing light. The heat of the sun will do the rest.

Where I live in northern Alberta, the heat of the sun is often not enough to melt off any residual snow. It is often necessary to clean them off entirely, although if we get a good wind, that may work as well.

I have my panels mounted on a tiltable array on the roof of my home, and in winter I set them to about 15 deg off vertical. Most of the snow here is light powder and thus the majority usually sloughs off. Sometimes the powder snow does stay on, and even if the majority of the snow does slough off, it is common for it to get hung up on the lower frame edge which protrudes (my panels are oriented horizontally length wise).

To clear residual snow, I made up a long (16 plus foot) handle and attached a t shaped brush to the handle. Just takes a few minutes to clear them. We don't get heavy wet snow here very often. Almost always light powder.

[DanS26]

To clear residual snow, I made up a long (16 plus foot) handle and attached a t shaped brush to the handle. Just takes a few minutes to clear them. We don't get heavy wet snow here very often. Almost always light powder.

Something like this...I just bolted three snow brooms together....cuts the time involved in half.

[bcroe]

Something like this..I just bolted three snow brooms together..cuts the time involved in half.

I copied that; does save a lot of time. Still need the smaller one sometimes.

Still haven't gotten a combination of sun & temp that will melt the ice, Tues
looks like it will. Meantime have to settle for 4 or 5 KW. Bruce Roe

[SunEagle]

I copied that; does save a lot of time. Still need the smaller one sometimes. Bruce Roe

Will that broom work if the snow isn't removed immediately and becomes ice?

[DanS26]

Will that broom work if the snow isn't removed immediately and becomes ice?

Will not remove ice, but I have found that if you can remove the top layer of snow and get down to 1" or less of the crusty stuff, a somewhat sunny day will clear the panels.

Like Bruce said its effective up to about 4" of snow....more than that you need to use only one broom.

[bcroe]

Will that broom work if the snow isn't removed immediately and becomes ice?

I don't see any safe way to get the ice off. Its pretty thin, so keeping loose snow off helps
some sun get through. Not enough to melt ice at 5F, but should make at least 25 KWH today.
Not seriously worried; built my reserve in summer, don't have high expectations for Dec/Jan.
Bruce

[SunEagle]

I don't see any safe way to get the ice off. Its pretty thin, so keeping loose snow off helps
some sun get through. Not enough to melt ice at 5F, but should make at least 25 KWH today.
Not seriously worried; built my reserve in summer, don't have high expectations for Dec/Jan.
Bruce

I understand. Hopefully all that frozen stuff doesn't hurt any of your panels.

5F today up there? Now I remember why I moved to sunny Florida. It got to 38F yesterday morning which is a little cool for me but a whole lot better than below 32F.

[bcroe]

I understand. Hopefully all that frozen stuff doesn't hurt any of your panels.

5F today up there? Now I remember why I moved to sunny Florida. It got to 38F yesterday
morning which is a little cool for me but a whole lot better than below 32F.

I never got used to wind chill factors of -30F. But some of us live in the "wild west", and
put up with a couple bad outdoor months each year, because we have a very long list of
reasons not to live most anywhere else.

This is the second winter, haven't lost a panel yet. Its very easy to periodically check on
a ground mount, with good sun & a clamp on DC ammeter. Bruce

[SunEagle]

I never got used to wind chill factors of -30F. But some of us live in the "wild west", and
put up with a couple bad outdoor months each year, because we have a very long list of
reasons not to live most anywhere else.

This is the second winter, haven't lost a panel yet. Its very easy to periodically check on
a ground mount, with good sun & a clamp on DC ammeter. Bruce

All true. I guess if you compare to a couple of real cold months a year as to a couple of Bad Hurricanes every 10 years you could be considered the winner.