Cleaning solar panels

Was just up on the roof because the installers left a Makita battery up ther mine now :laughing: while up there I was shocked to see how dirty the panels were, being such a nice day 26 degrees not a cloud in the sky I had to do something about it, not wanting to use a hose or drag anything heavy up there I found this and worked nicely job done in 10min.

Ps used a little dishwasher soap in the spray bottle attached to cleaner.
If anyone else has any cleaning advice and what cleaning products to use i would love to hear it.

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Anyone know where to buy theres brooms

On 2nd thoughts im sure i can make my own with any plastic broom and gardening watering/hydroponics products.

Is it worth cleaning the panel’s?

My panels have to be cleaned avery three to six months. If we get a good downpour of rain I will skip one cleaning. I have tried to assess the results of cleaning and can see from 5 to 7% improvement is capture. It would all depend on how much grime collects on your panels…dust and bird droppings seem to be the worst offending contaminants.
I initially looked it up on the internet and the responses were all over the map from “must do” it to “it doesn’t matter.”

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Totally worth it for me. I live in San DIego by the airport and 5 freeway and get a lot of grime. I try and clean them 2X per year and simply use one of those cotton window cleaning wands with NO water. The dust just wipes off and using any solution simply makes a mess. Roof is flat and too high to get a hose up to. I’d probably do it more often if it wasn’t so dangerous getting on the roof. It’s worth an instant 12-15% in generation the following day!


I hadn’t cleaned my panels for almost 5 years when I finally gave it a go. Almost 30% improvement in daily energy generation.


I haven’t measured scientifically, but I have three aspects on my suburban house in London, UK. I sent a light, small friend up a ladder and she managed to clean most of two aspects (safely) but the third proved harder given “normal” ladders. I noticed an improvement but am going to wait until next spring before trying again with better, safer gear and then measure for similar days and weather.

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Here’s a comparison that shows the difference either side of when the panels were cleaned. I think I cleaned them on Sept 30 but had to wait a few days for a cloudless day. This shows 14% improvement and is about as close to scientific as I can get.

This shows how close the runway and freeway are:


Nice pic UkiwiS & thx the the replys guys.
Love that roof i dont know if i could put panels up there tho looks like a nice spot for a bbq & roof garden.

Anyone know what the Professionals charge to clean per panel. I’m an ex rock climber have no problems with heights thinking about going into business, cleaning residential panels.

Found these guys should have my free quote soon
If it’s any more than $2 a panel they can go screw themselves lol

I have very similar results here but I clean mine twice a year.

In the UK I would expect a residential clean to be north of £100 for two average aspects - which I am not willing to pay. On the other hand, doing it properly with non-abrasive tools, deionised water (as the panel makers recommend) and liability insurance makes it understandable.

Take a look at Karcher and other’s “professional” tools for cleaning this stuff and get scared.

Thats crazy 100 pounds is insane no way it’s worth it when a heavy downpour will do it for free.
And I was thinking along the lines of $50 minimum
You could also included a tile repair service/ roof inspection charging people for braking any tiles while up there lol

Most likely half the service price will cover their insurance

Solar panel Coatings has anyone got any experience with them are they worth it do they work?

Found this is a little old tho

I’m wondering if just a silicone spray would help, don’t know if it will block/reduce visible light though
WD40 PTFE spray looks interesting ptfe ( Polytetrafluoroethylene) or Teflon going by Wikipedia meant to have low reflective properties.

Going to have to do a test on some small panels i gess.

theres a guy around here that charges $10 per panel

Got up on the roof again this moring with the hose and the same floor/tile cleaner and are now pulling more power then never b4

18x300watt ETs 5.4kw

Sorry no b4 pictures

I have a 32 panel ground mount array and nine more up on the garage roof. I can clean the ground mount array with this O’Cedar Dual-Action Flip mop head on a window washer extensible 12 foot pole.

I clean them about every two weeks for most of the year because of the alley that cars drive down and kick up lots of dust. The pecan tree dusts them pretty good in green pollen every spring too. I use a plastic container long enough to put the mob head in to wet and clean the dirt off after washing two panels each time. Use the scrub side to clean off the grime and the micro-fiber side to dry. I don’t use a hose to keep the amount of water dripping off the panels to a minimum to not feed the weeds. Takes about an hour to clean both arrays. I have a permanent ladder to get up on the garage roof.

Ha ha LOL. I need to get into that business. Let’s see I would charge $4100 for my job.

i gave mine a clean there was a fair few spots on it and a shitload of dust.
they have been up for 6 months

i cleaned them the day after and halfway into the day for my comparison days to see the difference immediately and also the next day would be the best comparison
temps were very similar and no clouds either day except for a tiny bit towards the end.

dark green is day 1 light green is day 2
the first arrow is when i started cleaning them, i shadowed them while cleaning so that’s the quite sharp drop off.
my only assumption is they increased slightly due to being a cooler temp with the water for cleaning once they warmed back up it didn’t show any difference

i just used rain water and a windows squeegee thing
i cant see any justification to pay someone to clean the panels where the cleaning will pay for the clean before needing to be redone