I have an unusual application that I wanting some advice on to see if a drone may be feasible. We have a remote business here that relies on internet through an antenna powered by two small 60W solar panels. It works well, but we are having issues with snow accumulating on the tops of the panels and sitting for days during the winter which is draining the batteries excessively to the point where the link fails. The batteries can survive a day or two without sun, but this snow can sit for well over a week before being melted which is too much for the batteries to handle. 

The antenna is about 1/2 mile away up on a ridge about 300-400 feet higher than the buildings here. There is no vehicle access up there and its difficult if not dangerous to head up there with any chance of ice since there are precarious ledges and sheer drop offs in a number of spots. I am wondering if using a drone with a small camping type infrared propane heater would be feasible to clear the snow off the panels.

I know IR heaters are often used to melt snow, but I am not so sure how easy this would be for a drone. It would have to hold position well within a 2 cubic foot box. Its all line of sight from our property and every property I have to cross is leased or owned by me.  

I have some past experience with gas RC helicopters in college and could fly them well, but that was a long time ago. Otherwise, I have little experience with drones, though I find them fascinating. 

I guess the 2 questions are first if you all think this is feasible and / or recommended. Secondly if feasible, we would have a budget of about $1200 or so. Is this remotely possible for that kind of money? I might be able to justify more just for the fact that this sounds like a cool way to clear off solar panels, but when it comes down to it, anything much more expensive and we could probably upgrade the batteries for a couple thousand and fix this problem another way. 

A picture of the antenna is attached. 

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...but a lot less fun

Truly thanks all for your suggestions on panels. However, many of these options you are suggesting, just are too complicated to install on this ridge. I am sorry if I just can't give you a clear mental picture of this ridge we are talking about. I know these are great ideas for a house or readily acccessible area, but its just not doable in a remote location.

I wish I could take you all up on this ridge to see it, but obviously just isn't possible. Maybe I can go take a video in a day or two. Let me try to explain a bit more... Wind loading on this ridge is up to 140 mph during bad weather. Being up there is being on top of a mountain. Its a totally different world. Everything under you is solid rock. There is no dirt to mount anything. You have to climb on all fours at certain points to get up there. No ATV or 4 wheel drive vehicle can get close to the top of this ridge because it just loose very large boulders the size of dump trucks. (Imagine God dumped a bucket of boulders the size of dump trucks on a hill).

You can't bring any sort of generator up there other than what you can fit in a back pack so operating any AC tool over 500W is out. There is no power at all. To mount the steel base took several hours of hammer drilling with battery operated tools and that was just three 1/2" threaded steel anchors (this stuff doesn't drill easy like concrete, I thought a typical 18V Milwaukee/Dewalt hammer drill and carbide hammer drill bits would plow through it, but it didn't....). Also, the rocks are obviously not level at all. We put the antenna on about the only 10 square feet of space we could find.  

The engineering on this antenna was also not easy. Every piece had to fit in a backpack yet withstand wind loads of 500 lbs laterally just from the small 60W panels we put up there and the antennas themselves. It took many dozens of trips up there just to install the very small amount of hardware present. 

Keep in mind like I said at the beginnings of the thread, I can fix this problem just by installing extra banks of batteries which is a far easier solution than any wiper, flipping method, motorized shutters, etc. A battery bank is just a small 12 x 12" steel enclosure that weighs about 60 lbs that I can pole mount anywhere and carry up in pieces. Its still going to require a completely separate custom enclosure that is bolted to a boulder somewhere, but at least its still a straightforward solution that I know will work for about ~$1000-2000.

The problem is not the panels. Its how long the batteries can last with ice or snow on the panels and the batteries not getting recharged. 

At best, I get 2 days right now. If I can last over a week just by putting in 2 more battery banks, my odds are extremely good of snow melting off by then. Its rare to have snow sitting much over a week with zero sun. 

Just a few other notes, the panels are already at 40 degree angle which is quite sloped. I can't slope any more than this because wind load. (imagine pushing on a 6 foot high pole with 500 lbs of force). We are already using the largest guy wires I can given the anchor size. The mount was custom made on a CNC plasma cutter to bolt to a rock face at odd angles. This isn't like a house roof or a flat piece of ground where you just buy a mounting kit and go for it. 

A few other things about the IR heater on the drone. IR heaters work like the sun. They don't heat up surfaces like a blow torch. It won't break glass. You know those long tube heaters they use in warehouses? Those are the exact same thing. I got the idea from our own infrared tube heaters in the warehouses. Our reach forklifts can be absolutely covered in snow, but as soon as you drive them under those heaters, the snow just melts off within minutes. The surface of the forklift heats up to 90 degrees or so, but nothing hot. 

Again, thanks again for your suggestions and sorry I can't explain quite what we are looking at clearly. If there are any solutions with a clear plan on carrying items less than 50 lbs on a backpack that is guaranteed to work, I would consider it, but I guess in my mind, it seems like the drone idea is still a good one. 

Noah... have you not heard the phrase "better living through chemistry?"

You can set up an Iris or 3DR X8 to carry a small amount of chemical deicer (MgCl for example)

And trigger the drop as long as you have set up a servo command to your de-icer product hopper. Heck, this can be a programmed mission if you rig up a functioning hopper w/ release.

Iris can carry about 500 grams, or so, max...X8 a lot more. A little goes a long ways... all you need is to get a small amount of sun to the dark panel surface, and physics will do the rest. So... drop all the deicer in a small area, and melt a hole in the snow... and off you go.

That is friggin' good idea David!!!! I hadn't thought of that. You are correct. It would be world's easier than an IR heater and the drone just drops it off and comes back. I like it! A 3DR X8 looks pretty fancy. How much is such an animal?

Use alcohol (Cheap Vodka) and not a chemical deicer which leaves behind a residue, which reduces efficiency. The alcohol also will help clean the glass.

aw shucks.  So, an X8+ is $1350...https://store.3drobotics.com/products/x8-plus?taxon_id=32

I'd just make multiple trips with an Iris+ (they are going for $550 now)  I have been able to do multiple iterations of a programmed mission wit my Iris, and have had pictures taken and landings made within mere inches of the previous flights, so the system is uncannily capable and accurate.

The Iris has three mounting screw locations on its underbody....I'd think plywood and balsa would be easily kitted together to make a de-icer hopper.  Test at (Colorado) altitude tho to see what your max payload can be....

$1350 isn't out of the question if it works well. I would only fly the thing in low wind and stable, albeit very cold conditions so I wouldn't expect any huge problems. If I wreck a drone after a year due to some equipment failure (or my failure), but have a ton of fun in the process and still keep the link active, I consider that a success over all. 

I haven't ever used alcohol to melt snow, but I certainly certainly try that as well. Cleaning off the glass is good as well. The birds do crap on the panels quite a lot up there. Usually its pretty insignificant as far as losses from that, but if it helps remove some of that all the better.

Now, if a drone does crash and you can find and retrieve it, is it usually a few hundred in parts or completely totaled? I guess from my RC helicopter days, a decent crash would mean a couple hundred dollars in parts on a $1500 bird, but usually the electronics were salvageable since they were protected. Is is about the same?  

UV tolerance?

Or try this super hydrophobic coating, water drops literally roll right off.


It may lightly fog the glass front though possibly reducing the solar collector efficiency.  


Just a thought, it might be worth waterproofing the parts as best as possible on whatever drone you get

A crash in on that ridge in icy conditions means the drone is probably staying out all night/week

Might also be worth looking into if the battery pack needs some insulation it sounds like it will be flying in uncommonly low temps. 

On the non-fun side of things a bottle of your chosen anti-freeze mix, a small pump (car windscreen pumps take a few amps but would only be used very briefly) and a drip feed from the top of the panels would be cheaper and easier, either have it triggered wireless or set something up to compare the ambient light to the panel output and have it triggered automatically. It'd surely work out cheaper.

How about a salt bomb? 

If you need dispersal, perhaps pump some salt water in a spray pattern. 

Solar panels are used in the marine (salty) environment all the time so, the panels should not be negatively affected. 

Think about corrosion...you want to not use salt that will cause problems with this equipment.
Secondly, some of you guys are forgetting that using a quadcopter to de ice the solor panel has an element of fun.
The non drone solutions maybe cheap, but not fun to use.

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