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Tips for cleaning/maintaining your panels

svetz

Works in theory! Practice? That's something else
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How do you clean your panels? Got a tip for cleaning or maintaining panels? How do you deal with tree sap, gunk or other corrosion that happens?
Post it here!

In general panels at greater than 10° tilt are self-cleaning [ref], but even then they might need the occasional cleaning. So...

How to clean your solar panels

Ammonia Alert
Before cleaning your panels with an ammonia based product (e.g., Windex, Sprayway) check the datasheet.

Not sure how serious it is, but I know panels have certifications for ammonia ratings (typically most important for farms where fertilizers are used).
Reference: www.powerfromsunlight.com/the-most-important-ammonia-corrosion-resistance-standards-for-pv-solar-panels/; so that makes me think ammonia would be bad for some panels.

Thermal Shock
I've seen numerous warnings that cleaning by hosing them down should only be done while the panels are cool to avoid thermal shock.

Coatings
You might also be interested in: https://diysolarforum.com/threads/water-repellent-coating-for-solar-panels.131
 
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Most panels just get dusty and a few shots of bird crap. A hose and a foam brush / squeege combination thing and your done. I don't see the need for any cleaning chemicals in most situations.

A chainsaw will take care of sap problems.
 
I keep a dead t-shirt near mine.
(Single panel 100w)
Wipe if off when needed.

Mostly dust, leaves, And cat footprints...

When I eventually get my real system put up I will keep a long mop or car Window cleaning thing near it.

I haven't considered cleaners! I figured rain and wind and angles would keep it clean. But that's a good consideration!

I would probably just use hose water. But there are minerals in it, so maybe just using rain water is better.
 
I know I need to scrub the bird poop off and obvious things like that. What I wonder is if there is any reason I shouldn't put Rain-X on my panel so the bird poop doesn't need scrubbing. Does something clear like Rain-X have any properties that will affect the rays of the sun? I use it all over my car. Windows, headlights, taillights.... like to watch the water bead up and blow off.
 
This is copied from my installation manual​
LG Electronics.
• Water, ethanol or a conventional glass cleanser
with a micro-fiber cloth can be used for regular
washing or rinsing of the front glass to remove
dust, dirt or other deposits.
• Aggressive and abrasive cleansers or chemicals
such as alkali chemicals including ammonia based
solution should not be used on cleaning the module.
• Always wear rubber gloves for electrical insulation
while maintaining, washing or cleaning panels.
• Deposits of foreign material on the frame surface
can be cleaned by using a wet sponge or cloth and
dried in air or by using a clean chamois.
PLEASE KEEP IN MIND ALL PANELS ARE DIFFERENT (in some way) > REFERRER TO MANUFACTURER MANUALS​
Unless it's DIY panel.
eddie1261
Do you have a bottle of this Rain X?
What is the active ingredient, the CHEMICALS in the mix (HASCHEM)? Very important that you don't compromise the glass lamination if any or the backsheet of the panel!
Note* the safety comes after the what to clean with...
Too late I'm suffering electrocution and the Ethanol has reached it's flash point. For those who only read part their of.
 
The do make spendy cleaning product especially for solar panels that might help with the spotting. If I had nothing else, I would use a tiny bit of biodegradable dish soap. It doesn't rot my hands like Dawn, it gentle to the environment, and probably more gentle on the panels. I wonder if an anti-spotting agent like what they use on glasses in the dishwasher would help or if it is too chem. I have heard of using distilled or de-ionized water to prevent spotting, but whose got that?. Drying or squeegeeing, but your panels better be really clean if you squeegee or you will scratch glass. Water softened with salt is worse than regular water. I guess you could just scrub when it rains, but then you might get electrocuted by lightning or fall off the slippery wet roof. I like power brushes as you don't have to try so hard to scrub, its quicker and reduces your chances of falling off the roof. The Worx Hydroshot carwashing brush is kinda cool, but too short. The German's have power brushes. Search YouTube with "solarreinigung". There is also some German Clean-tec dude in California with German brush system cleaning solar panels and drinking beer in a hailstorm in Pescadero, CA. Anyway, no one around my home here in the suburbs seems to be washing their panels. Solar panel cleaning technology is way behind solar technology. We've had fires and I look out of my kitchen window on three nearby houses of dirty panels. My screens and windows need scrubbing too. It is sketchy to stand on a roof with a brush even though I was once a gymnast and still have pretty good balance. I also fell 30 ft off a rope swing once and I am not an idiot. I think I want to put my panels along the back fence where the sun is nice and I can wash them.
 
Also put me in jail for criminal damaging as the offending tree is in my neighbor's yard.....
It is legal to cut branches that hang over the property line and are therefore effectively on your property. It won't help if it is just a shade only issue, but it might help with sap/shade. Oak sticky is nasty stuff.
 
I know I need to scrub the bird poop off and obvious things like that. What I wonder is if there is any reason I shouldn't put Rain-X on my panel so the bird poop doesn't need scrubbing. Does something clear like Rain-X have any properties that will affect the rays of the sun? I use it all over my car. Windows, headlights, taillights.... like to watch the water bead up and blow off.
Actually, if you were dealing with Oak sap which is so gnarly it would be worth the risk to use something like RainX
 
It is legal to cut branches that hang over the property line and are therefore effectively on your property. It won't help if it is just a shade only issue, but it might help with sap/shade. Oak sticky is nasty stuff.
This is a bit off topic, but a neighbor of mine has a nice crepe myrtle tree with some branches hanging over my side of the fence. I recently learned about the technique of "air rooting" or "air layering" and I think I'm going to try that on one of the branches over my yard, then cut the branch down and plant it in my yard so I'll have a nice crepe myrtle tree, too. Neighbor is a friend of mine, and he has taken sprigs of one of my plants, so I don't think he'll object.
 
Really, a crepe myrtle. Those have such obscene colored blooms in the late-mid summer. Not a fan myself. I like trees that look like trees. You can have them as a bush, though
 
California study saying no to panel cleaning unless you've dirty birds (they didn't consider ash though).

Google study says wash 'em if they're flat mounted, still no ash references....

Canvased google:

Wood Ash
Rinse with a hose seems to be the generic advice. Smoke typically has oils as well as particulates so might need some sort of soap. Wood ash is somewhat abrasive, but some people claim you can use it to polish glass.​
Volcanic Ash
Sounds like covering them up early is best. Possibly a coating applied before hand (see Unelko)?​
Volcanic" ash seems to be a bit sticky and what can't be rinsed off might need to be scrubbed with brush (but volcanic ash is abrasive, so work gently or leave it if not impacting performance). This article recommends an N95 mask and goggles when working around volcanic ash. Once "wet", it's hard to see any remaining bits. If you do have a section of glass dulled by scratches you might try the toothpaste trick or something like rain-X.​

 
Really, a crepe myrtle. Those have such obscene colored blooms in the late-mid summer. Not a fan myself. I like trees that look like trees. You can have them as a bush, though
When people cut them way back in the winter so that they grow up like a blooming lollipop, then I somewhat agree with you, but if you allow them to grow like trees, the wood and bark are beautiful as well.
 
I just aimed a garden hose at a panel this week, and the ash rinsed right off.

(most) PV panels are tempered glass, which helps with the thermal shock issue.
The other month, as I watered front yard in the evening I often aimed at our windshields to clean them.
Then one day I was there earlier. Remembering what I read on this forum shortly before, I said to myself, "Nah, not a big deal. Windshields get sun and rain all the time." I sprayed the hose across the windshield of our Sable and heard, "crack". Couldn't see anything then, but two days later there was a big crack. Original, 20 year old windshield had been fine until Hedges thought he knew better. Cost me $200.
 
You might have observed the overall efficiency of your system getting reduced after a month or so.

I hope you found it helpful!
Oh yeah those solar panel cleaning robots are a must have for diy solar users.
Nice job of spamming your link with a so so post. :)
 
 
Oh yeah those solar panel cleaning robots are a must have for diy solar users.
Nice job of spamming your link with a so so post. :)
The post seemed extremely commercial, I must acknowledge that, but the video of solar panel cleaning robots that will “blow your mind” contains some pretty worthwhile designs.

The post contains an honest reckoning with the reality that water is not always readily available, which is true.

Makes me wonder if just plain pressurized air would provide any cleaning action. Maybe reduce frequency of need for water based cleaning methods.

My personal favorite trick is to use solar power to condense moisture from the air into a liquid phase and then use that to clean the panels. Of course there are challenges to this approach eg growth medium. Filters mitigate that, but increase power usage. It’s possible to generate your own water to clean panels, with the electricity from the panels.
 
I used to apply RainX to everything. E v e r y t h i n g. Now I apply ceramic coating to everything. Being super hydrophobic it doesn't prevent things from sticking 100% but it makes rinsing off much much easier and bird poop etc doesn't stick.

Adams claims to prevent water spots and it does, but it isn't as thick or long lasting imho as other ceramic coatings I've used. The entire front end of my rig is ceramic coated and all of the rubber, plastic and metal wiper arms are coated with CeraKote. Fanastic product! I discovered it on the Project Farm youtube channel.
 
Solar panels have an AR (anti-reflective) coating on the glass, partly to lessen loss due to reflection, and partly to prevent glare.

That's why there are warnings against using abrasive cleaners or scrapers. However, removal of the top AR coating would only result in about a 3% power loss.

Adding a shiny (or any) coating on top also defeats the AR purpose. Power loss in this case would be specific to the added reflectivity.

P.S. Under the glass, the solar cells themselves also have an AR coating, one that is very important, as silicon normally reflects 30% (!!) of the light.
 
I live in So Cal 30 miles north of Hollywood, so, basically on the edge of a desert. Between the dust and ash from wild fires, my solar panels get a nasty layer of brown powder on them. I have now rinsed them off for the 5th time in 2 years. I typically see about a 6% improvement the next day. I think it will be more like 10% this time, they were bad. I have a very soft brush with a nine foot rod. I use it on my lower set of panels to whisk away most of the dust. Then I just lightly rinse off the remains. The only time I put any scrubbing force on the panel is if there is a stubborn bird poop. I can't really (safely) get to my second set of panels, so I just rinse them. That upper roof is a bit higher up, so it seems to get less dust and more wind, so they never seem as dirty, and it shows in the production, they make about 3% more than the lower roof in the same conditions.

I will only hose them when the weather is cooler, and I also use a very light mist at first to cool the solar panel slower. Don't want to shock them with a rapid douse of cold water.

I may have to try that ceramic coat stuff. Has anyone checked it if reduces the energy production?

Edit, it has been a bit over an hour since I rinsed the panels today. See if you can see where I cleaned them.
Solar panel cleaning.PNG
There is a nice little bump up in production around 3PM. I think they needed it.
 
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