Dust on solar panels

[windy]

 I have been looking into and reading all I can about solar panels, and one thing that isn't talked about is, do the panels have to be washed if dust builds up on them. If it doesn't rain for a month or two and the panels are on a steep roof, that could be a real pain. I'm not sure if dust build up would be a problem, but I would think that it would reduce output. Any comments?

windy

[Errol]

yes you will loose power as the dust increases it works like a light filter

[DanG]

Glass itself maintains very little static charge to attract dust on its own...

[wooferhound]

The Mars Rovers keep accumulating dust on their solar panels. The spacecraft engineers keep saying they have to reduce the rovers workload to compensate for the reduction in power input.

[Capt Slog]

Can't you reach them with a hosepipe or jetwash?

I've spent several holidays in Greece, nearly all the hot water is provided by solar.  On a few occasions I've managed to get onto the roof to look at the panels, and have been amazed at how filthy they let them become.  The owners of the apartments will spend a lot of time washing down patios etc, so water isn't an issue, but they never think to give the panels a quick wipe!

.

[Jeff]

Yeah, you could hose 'em down, but the power requirements to push all that water to Mars cost us taxpayers a bundle!

Really though, I got some stuff from the auto parts store called Rain-X. A lot of people don't like it because you have to keep rubbing with a VERY clean rag until all the streaks are gone. It's like car wax, except made for windows. Once treated, they'll stay that way for a good 6 months, and even a good breeze will blow off most of the dust. If you can reach them with water, they'll rinse off clean as new! In a pinch, a good car wax will work. Any loss from the coating will be made up for by keeping them cleaner from dust, pollen, etc. Again, make sure you apply it properly, and remove with a clean rag. Do a good job, it's worth it!

[Bruce S]

Rural McG;

 You best me to it :-) so I'll 2nd your idea. This IS what I use on mine too. I buy the single enevelops and use when it seems worn out by sunshine, about 3 times last year.

BTW: Works reall good on snow too -)

Cheers

Bruce S

[Jeff]

Down here (on the NC-SC border), the pine pollen gets so bad in the spring it'll reduce output by half in one day! Even treated with Rain-X, I kept a 2 & 1/2 gallon garden sprayer where I could spray the dust off the panels every day about 1-2pm.

[windy]

Thanks for all the replies. I'll try Rain-X and see how that works.

windy

[SteveCH]

When I installed my first rack of panels in 1985, I put them on the roof. Here we get not only pollen [May/June] and dust [always] but also snow in the winter. Don't believe anyone who says "don't worry the snow slides off on its own" as it sometimes does but often does not. I rigged up a pole made of sections of an old tent-like cover my wife had for some crafts fairs, you know, aluminum tubes that slide together so they can be broken down to three feet long or so for transporting. I strung them together to make them VERY long and put a brush on the end. It was unwieldy but worked, if a bit of a hassle. It broke down, of course, to a collection of short pipes.

Then I had to reroof the house, and I pulled the array apart and down to the ground. I decided to increase the array size and to go through the hassle of putting it on the hillside above my house [longer wire runs, increased wire gauge and more weather protection for it, etc., concrete footer to pour and so on].  Major pain, but now I can walk up to the panels and brush them off with a broom [snow] or, few times a year, a soft brush and pail of water to clean off pollen and dust.

I haven't tried the auto stuff, I just bite the bullet and go clean them. Nowadays, from the ground, it is no big deal and takes me five minutes.

But, in answer to the main question, you would be smart to keep them clean. It is also an opportunity to give them a look over. I cleaned an elderly neighbor's for him last year. He is blind and could still tell he wasn't getting the output he expected. During cleaning, I kept an eye out and discovered a place where one panel had a severe burn in the silcon wafer...even a break and cracks in the glass. Couldn't figure out what caused it, but the effected panel was in the middle of the array and was blocking the juice from the panels behind it. I wired around that panel for him and he was back in business til he got it replaced. You could not see the damage from more than a few feet away, and if I hadn't been cleaning them up close and personal I would've missed it.