What cleaning tools do you use?

[Tyler]

Here in AZ we go with out rain for quiet some time and half the time it sprinkles for two minutes, just to insure everything that had dust is completely dirty now. I have read the forums that show improvement after the panels have been cleaned.

- Is cleaning panels something most of you do?
- What tools do you use, techniques, just a water hose...?

I don't mind doing it myself, but want to make sure the effort is worth the reward and I am not just drinking the kool-aid!

If there is another thread that this has been discussed in please let me know. I know several threads that show the results and I can tell some are doing it, just not sure if some is 2% or most on here do it.

Thanks.

[Enver Solar]

I have read the forums that show improvement after the panels have been cleaned.

Hosing them down once or twice a year should be all that is required. Just keep an eye on your monitoring system to know when it needs cleaning. ~Megan

[Mike90250]

I clean mine with a hose & nozzle, early in the AM, while they are still damp from the night dew. Everything (bird poop & dirt) rinses off pretty well.

if you have hard water, you don't want to leave white spots (mineral deposits) and may need a Deionized Water rinse. The "Mr Clean car wash" kit has a DI cartridge in it that is great for panels.

[ILFE]

I've been trying to find a squeegee here, but have yet been unable to. I was going to use it after hosing my panels off.

Considering my north latitude location, currently, my panels have to be almost flat.

[MGE]

For me I clean them about once a month in the am before it gets hot and I can see an improved output after I'm done. I use a 5 ft scrubber/squeegie and run a hose onto the roof, spray them down, squeegee them dry. Thirty four panels and it takes me about 45 minutes to an hour. Clean the bird droppings off and such.

[Volusiano]

If you live in Gilbert, AZ, you probably have very hard water, because I live in Chandler, AZ and my water hardness is around 800 ppm TDS (Total Dissolved Solids), which is extremely hard. So if you have very hard water, you can't just hose off the panels and let the hard water dry off by itself, You'll have mineral stains on them and they'll be very hard to take off after a few buildups, and then you'll need to get close enough to scrub them off with lots of elbow grease. So you must make sure you squeegee it dry or mop/towel it dry somehow. The only way to let water dry off by itself without any stain is if you have a water purifier/filter system to generate pure water for use in cleaning or at least final rinsing.

The Mr Clean car wash kit's DI cartridge is not available for sale anymore from what I can tell. Even if it is, it'd be a very expensive option. If you have an RO filter system in your home, you can probably get the filter water from there and buy a pump and pump it through a DI cartridge to get pure water and store in container(s). Then pump it out for final rinsing.

There's also the issue of how easy or difficult it is to access your panels. If your panels are lined up in just 2 long rows, it's not too bad to get close to them. If your panels are connected in a big slab (like mine which is 4 rows of 11 panels in the portrait mode layout altogether) it's going to be hard to get to the 3 rows further away from you without a pole.

Then there's also the question of whether hosing them down is good enough, or do you need to scrub them to get them clean? It depends on whether you live near a main road with lots of traffic that spew oil/gas into the air and make the dirt grimy or sticky or not. If hosing off is not good enough, for sure you don't want to pressure wash because you don't want to ruin the seals around the panels. That leaves you with the brush on a pole option. If your panels are hard to get at, you'll need an extendable pole with a brush. In this case, a pure water fed pole may be required. In some cases, soap may be also needed. Even the choice of soap needs to be considered because you don't want any kind that can damage the panels' seals.

And if you have tile roof, do you want to walk on the tiles and risk breaking them or not? Then there's also the safety issue of walking on the roof. You'll have to consider if you need a safety harness tethered to an anchor point while you're out and about on the roof or not. Or can you butt up an extension ladder again the bottom of the roof and clean from there?

So as you can see, your approach to effective cleaning depends on lots of variables. The approach someone else uses to clean their panels may not the an effective approach for you, depending on how similar or different their setup is compared to yours.

As for the ROI on cleaning, I've heard anywhere between a few % to 10% improvement, with 4 to 5% being the average. It really depends on how dirty your panels are.

A good rain may be good enough to clean your panels. Rain mixed in a dust storm may make your panels dirtier than before.

There are professional solar panel cleaning companies in AZ you can hire. Most of them will probably use the purified water fed pole with a brush approach. They'll probably charge you $5 per panel in addition to a trip charge. The question is whether there's enough ROI on hiring professional cleaners or not against the $ saving based on the performance improvement after cleaning. I would surmise to say the ROI usually is not enough unless you do it yourself.

Most places in the country can let rain take care of the cleaning. However, the AZ desert environment is a different animal altogether, so you should have your own cleaning strategy and not rely on mother nature to take care of it for you.

[Tyler]

If you live in Gilbert, AZ, you probably have very hard water, because I live in Chandler, AZ and my water hardness is around 800 ppm TDS (Total Dissolved Solids), which is extremely hard. So if you have very hard water, you can't just hose off the panels and let the hard water dry off by itself, You'll have mineral stains on them and they'll be very hard to take off after a few buildups, and then you'll need to get close enough to scrub them off with lots of elbow grease. So you must make sure you squeegee it dry or mop/towel it dry somehow. The only way to let water dry off by itself without any stain is if you have a water purifier/filter system to generate pure water for use in cleaning or at least final rinsing.

The Mr Clean car wash kit's DI cartridge is not available for sale anymore from what I can tell. Even if it is, it'd be a very expensive option. If you have an RO filter system in your home, you can probably get the filter water from there and buy a pump and pump it through a DI cartridge to get pure water and store in container(s). Then pump it out for final rinsing.

There's also the issue of how easy or difficult it is to access your panels. If your panels are lined up in just 2 long rows, it's not too bad to get close to them. If your panels are connected in a big slab (like mine which is 4 rows of 11 panels in the portrait mode layout altogether) it's going to be hard to get to the 3 rows further away from you without a pole.

Then there's also the question of whether hosing them down is good enough, or do you need to scrub them to get them clean? It depends on whether you live near a main road with lots of traffic that spew oil/gas into the air and make the dirt grimy or sticky or not. If hosing off is not good enough, for sure you don't want to pressure wash because you don't want to ruin the seals around the panels. That leaves you with the brush on a pole option. If your panels are hard to get at, you'll need an extendable pole with a brush. In this case, a pure water fed pole may be required. In some cases, soap may be also needed. Even the choice of soap needs to be considered because you don't want any kind that can damage the panels' seals.

And if you have tile roof, do you want to walk on the tiles and risk breaking them or not? Then there's also the safety issue of walking on the roof. You'll have to consider if you need a safety harness tethered to an anchor point while you're out and about on the roof or not. Or can you butt up an extension ladder again the bottom of the roof and clean from there?

So as you can see, your approach to effective cleaning depends on lots of variables. The approach someone else uses to clean their panels may not the an effective approach for you, depending on how similar or different their setup is compared to yours.

As for the ROI on cleaning, I've heard anywhere between a few % to 10% improvement, with 4 to 5% being the average. It really depends on how dirty your panels are.

A good rain may be good enough to clean your panels. Rain mixed in a dust storm may make your panels dirtier than before.

There are professional solar panel cleaning companies in AZ you can hire. Most of them will probably use the purified water fed pole with a brush approach. They'll probably charge you $5 per panel in addition to a trip charge. The question is whether there's enough ROI on hiring professional cleaners or not against the $ saving based on the performance improvement after cleaning. I would surmise to say the ROI usually is not enough unless you do it yourself.

Most places in the country can let rain take care of the cleaning. However, the AZ desert environment is a different animal altogether, so you should have your own cleaning strategy and not rely on mother nature to take care of it for you.

My situation is very similar to yours where I have them stacked 4 high. Thanks for the insight into to different options. Curious as to how you clean your panels and what your process it?

[Volusiano]

My situation is very similar to yours where I have them stacked 4 high. Thanks for the insight into to different options. Curious as to how you clean your panels and what your process it?

Since I live in a 1 story home (with vaulted ceiling), I tried both cleaning from top of the roof ridge downward, and cleaning from a ladder from bottom up (standing at the bottom edge of the roof. I like the bottom up approach better because I don't have to walk on the roof, and also my roof is fairly steep for my liking, although a professional roofer can walk that angle with ease, but not me.

Because I stack them 4 high in portrait mode and the bottom panel is about 7-8 feet away from the bottom of my roof, I have an almost 30 ft reach. I bought a fiberglass 30 foot extension pole for about $175 that came with a brush with a water fed line to the brush. I clean my panels with regular hard water first, then do a final rinse with pure water. I have an RO system at home under my kitchen sink so I get that water and run it through a DI cartridge to get the water down to 0 ppm TDS reading, store it in a couple of 6 gallon water containers I bought from Walmart. I bought a pump for about $90 from Amazon to pump this pure water out of the container up to the brush for the final rinsing.