Clearing snow from roof mount panels when standing on the ground

[WillEert]

I am never afraid to learn - although the process can be painful. Last year we put in two mini-split heat pumps - mostly to get cooling. They are powered up by two matching 6 panel arrays which I put on our buildings using a roof mount. I thought they would self clear as I was used to my other arrays that are at about 65 degree tilt angle however these roofs are 4:12 and 6:12, much less of a tilt. The heat pumps made useful heat and I got more interested in keeping them going during the winter.  I don't like to admit it but I have been climbing up and sweeping them off periodically this winter. I know that I do not need to fall off the roof even once to know it is a bad thing to do. So - I need to find a way to keep these arrays cleaned of snow without getting on the roof. An automatic system would be ideal. Failing that I will move them to a ground mount this summer. I have pondered a compressed air nozzle system? a moving clear cover of some kind? a rapping system?

Does anyone know something thta works? I am sure lots of people have this kind of problem - even with ground mounts.

Will

[boB]

Hi Will.  We had to get rid of some snow recently as well !

I wish that electric snow melting worked a bit better.  sometimes it can work.  High steep angles help of course.

boB

[ClassicCrazy]

I have an extension handle on a squeegee to reach the high panels of my ground rack but most of them I get with a push broom.
But I wondered if mounting one of those leaf blower fans on the side of the panels - maybe a few of them at different spots , would work to blow the snow off .  Sometimes I just tap on my panels and it all slides off like avalanche. But days like today after freezing rain turned to snow it needed some harder brushing action to get it off.

here are a couple videos of way to not do it the fast way
https://www.wimp.com/how-to-not-clear-snow-off-the-roof/
https://www.wimp.com/quick-snow-clean/

Larry

[ClassicCrazy]

I was playing around with time lapse earlier this winter and made a video of me clearing snow off some of my PV
https://youtu.be/TW0MGBhO01c

Larry

[WillEert]

It is winter here again in Manitoba - which means snow. In the off season (manitoba has 9 months of winter followed by 3 months of bad sledding) I bought a snow removal extension arm and scraper head for it. The head is designed for removing snow fromglass. So far it seems to be working fine. It is not automatic but does keep off my roof. For my shop roof array I can stand on a step ladder and for my house array I work from the ground.

I have learned there is the good design factor for snow removal also. We now have 4 arrays of varying pitch angles and orientations. This what I have learned:

1) The minimum slope for any hope of snow sliding off by itself  is 6:12. Much better is 12:12. My 4:12 array just sits there with the snow on it.
2) The panels shed snow  much better if they are in mounted portrait rather than landscape orientation.
3) Recessed or smooth panel clamps are much better than clamps with the bolt protruding from the clamp. I am mulling over some kind of cover for the gap between the panels with the idea of adding "slipprification" to the installation.

Humor of a kind: We had a particularly heavy wet deep snowfall early on this winter. The panels were covered with about 2 feet of snow that had wind slab in it and was packed quite solid. A real test for this device, I thought. I went up my 8 foot step ladder with the snow pro and started attacking the build up. Very slow going and very good exercise. Actually too good an exercise. After a while I wondered if I could chop off blocks and sent then snow down the roof in chunks rather than beaver away at the heap. The snow pro chopped quite nicely and I cut off a large chunk. I hooked the device to the snow chunk and gave a tug. I succeeded beyond my wildest dreams. Most of the snow on the array broke loose and accelerated down the roof. My error was immediately apparent. Think of the boy on the branch with the saw cutting off the branch he is sitting on. I was trapped up the 8 foot ladder with the snow heading for me. Luckily for me I built the array to code and had left the required clearance between the roof edge and the array. The snow caught on this edge and mostly slowed down. By hanging onto the gutter I avoided being thrown from the ladder. Whew. All's well that ends well!!

Two more pictures in the next posting.

Will

[WillEert]

The "head" gets damaged by the mid clamp bolts.

[ClassicCrazy]

Will  - your story of the snow sliding off with you on ladder reminded me of the two videos I posted in earlier comments .
Glad you didn't get buried .
I just watched a video of a guy using a piece of wire across a roof to cut it all the way across and then it all slid off in one piece.
Wonder if in an environment like you live with so much snow if putting a couple rails at the side of array with wire you could slide down would work for those really big snows.
https://youtu.be/Ugb5fyaVZx0

Larry