Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Do you wash your panels? If so, how?

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Moderator
Nov 28, 2018
15,090
19,495
Riverside Co. CA
I have hired a local company (that also does my windows once a year) that washes solar panels. My home is two stories, and has a cement tile roof, so I am not walking on it. The local company I use has been cleaning solar panels (and windows) for like 12-15 years.


I see a little better production when I have them cleaned, however to be clear, the extra production is not enough to pay for the cost of getting the cleaning itself. I just do have them do it while they are doing my windows, and to also support a local business owner who does great work.

TL ; DR, I have a company do it, I see some extra production but not enough to pay what it costs me for the company to do it, if you can do it yourself safely and live somewhere where it doesnt rain a lot (like we both do) it might be worth it.
 
I can tell you that I do notice about a 5% difference in production when the panels get dirty on their bottom edge. I clean them myself once a year with an extension pole from the roof (after pollen season on an overcast day). Once a year is enough for me. It takes me about an hour for 40 panels.
 

holeydonut

Active Member
Supporting Member
Jun 27, 2020
3,365
2,760
East Bay NorCal
Yeah I can't imagine the dirty panels actually freeing up much more energy... I guess the good thing about all the panel-specific reporting is that there's enough data points to inform if a specific panel is showing lower production over time (for changes unrelated to the position of the sun).

We can't wash solar panels, cars, patio furniture, or even spray out garbage bins right now anyway due to the drought. Sucks.
 
Yeah I can't imagine the dirty panels actually freeing up much more energy... I guess the good thing about all the panel-specific reporting is that there's enough data points to inform if a specific panel is showing lower production over time (for changes unrelated to the position of the sun).

We can't wash solar panels, cars, patio furniture, or even spray out garbage bins right now anyway due to the drought. Sucks.
Wash your patio furniture on your lawn or a portion of your yard that needs to be watered anyway in place of actual watering. This will be the most efficient use of water, double purpose.
 
  • Like
Reactions: pdx_m3s
I am able to get on my 2nd story roof to was panels. I just use a window washing mop maybe some soapy water, or not, and wash when pollen presents itself.
I tried to see if that improved production after washing but hard to tell, especially when someone compares a day apart. Temperature is a killer, so is any slight weather change that may not be visible to the eye. For accurate measurement you would really need some serious measuring instruments, one for the actual sun power and angle to the panels at time of measurements. .
But, sure makes one happy to subjectively see an increase.
So, just was and be happy. ;) :)
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Moderator
Nov 28, 2018
15,090
19,495
Riverside Co. CA
I am able to get on my 2nd story roof to was panels. I just use a window washing mop maybe some soapy water, or not, and wash when pollen presents itself.
I tried to see if that improved production after washing but hard to tell, especially when someone compares a day apart. Temperature is a killer, so is any slight weather change that may not be visible to the eye. For accurate measurement you would really need some serious measuring instruments, one for the actual sun power and angle to the panels at time of measurements. .
But, sure makes one happy to subjectively see an increase.
So, just was and be happy. ;) :)

@sorka did some testing on dust and production, and posted it:

 

sorka

Well-Known Member
Feb 28, 2015
9,592
7,891
Merced, CA
...maxes out at about 5% after about 2 weeks. Multiple panels unwashed daily optimizer output vs panels that are kept clean. If you're doing the same thing, then either swap panels and repeat or control against a months worth of production for each panel.

My washing steps:
  1. Wait for the sun to go down but not too late as you want some light.
  2. Rinse once with firehose nozzle Amazon.com: Gilmour 855032-1001 High-Pressure PRO Fireman's Spray Nozzle with Large, Red/Black: Garden & Outdoor
  3. Foamer gun using the mild car detergent. Amazon.com: Fasmov Car Wash Pressure Washer Jet Wash 1/4" Quick Release Adjustable Snow Foam Lance Foam Cannon Foam Blaster: Automotive
  4. 22" microfiber window brush on 30' pole Amazon.com: DocaPole 7-30 Foot Extension Pole - Multi-Purpose Telescopic Pole // Light Bulb Changer // Paint Roller // Duster Pole // Telescoping Pole for Window Cleaning, Gutter Cleaning, and Hanging Lights: Health & Personal Care
  5. Rinse again with firehose
  6. Final rinse with deionized water. Make sure it's a filter that you can see the usage status. Amazon.com: AQUATICLIFE Deionized Spot-Free Car Rinse Unit - Premium Water Deionizer for Car Washing - Spotless Car, RV, and Motorcycle Wash System: Automotive
The deionized water is only needed to rinse off the tap/well water. If you use the deionizer for all steps that require water, you'll just waste the filters because its the very end that counts.

I do it every two weeks. Takes about 20 minutes. I can do it all from the ground.
 
...maxes out at about 5% after about 2 weeks. Multiple panels unwashed daily optimizer output vs panels that are kept clean. If you're doing the same thing, then either swap panels and repeat or control against a months worth of production for each panel.

My washing steps:
  1. Wait for the sun to go down but not too late as you want some light.
  2. Rinse once with firehose nozzle Amazon.com: Gilmour 855032-1001 High-Pressure PRO Fireman's Spray Nozzle with Large, Red/Black: Garden & Outdoor
  3. Foamer gun using the mild car detergent. Amazon.com: Fasmov Car Wash Pressure Washer Jet Wash 1/4" Quick Release Adjustable Snow Foam Lance Foam Cannon Foam Blaster: Automotive
  4. 22" microfiber window brush on 30' pole Amazon.com: DocaPole 7-30 Foot Extension Pole - Multi-Purpose Telescopic Pole // Light Bulb Changer // Paint Roller // Duster Pole // Telescoping Pole for Window Cleaning, Gutter Cleaning, and Hanging Lights: Health & Personal Care
  5. Rinse again with firehose
  6. Final rinse with deionized water. Make sure it's a filter that you can see the usage status. Amazon.com: AQUATICLIFE Deionized Spot-Free Car Rinse Unit - Premium Water Deionizer for Car Washing - Spotless Car, RV, and Motorcycle Wash System: Automotive
The deionized water is only needed to rinse off the tap/well water. If you use the deionizer for all steps that require water, you'll just waste the filters because its the very end that counts.

I do it every two weeks. Takes about 20 minutes. I can do it all from the ground.
Wow, every 2 weeks?
I was wondering how long can you not clean it to get close to the unwashed panels production as that is how often one would need to was to get that increased production all year.
 

sorka

Well-Known Member
Feb 28, 2015
9,592
7,891
Merced, CA
Wow, every 2 weeks?
I was wondering how long can you not clean it to get close to the unwashed panels production as that is how often one would need to was to get that increased production all year.

Yes, although the dust does build up more after two weeks it seems to slow considerably. i.e. dust prevents dust.

That said, my neighbor got a huge ground array installed 6 months ago and the panels have never been cleaned. They are literally white with thick dust. I have to imagine it's more than 5% loss of production.

For me to test that, I'd basically need to leave an entire array unwashed for that long to compare with the other array which I'd keep washing. I don't think I'm willing to sacrifice that production.
 

sorka

Well-Known Member
Feb 28, 2015
9,592
7,891
Merced, CA
Hmm. Since his array is on the ground, maybe he'd let me clean a few panels. The problem is he's never gotten is SE access and I don't think he cares about monitoring the output so no way to monitor panel level output without getting into the account. He's the type that wouldn't know until is massive true-up came after a year.
 

Products we're discussing on TMC...

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top