Dont forget to clean your panels!

I finally decided to get up on my roof and hose off my panels again. I live near an orchard, and they shake trees occasionally, which throws dust over everything! I typically try to hose down the panels every couple months, but I have been lacking and its been more like 6 months. They were filthy!

I will add, I think paying some guys to come out and "power clean" panels with the scrub brushes and pressure washers are a waste of money. I just saw 3 of my neighbors had a guy come out and do that to all of them. I spent 20 minutes on my roof with a hose and they look the same.

Results! Can you tell a difference? 6/14 yielded 60.9 kWh, and yesterday yielded 73.7 kWh. Thats a jump!!!



Here is PV 3 specifically, these are the 6x 390w panels that are flat mounted on my enclosed trailer (link in my sig). They were the worst because there was nowhere for the dirt to go since they are flat. It was just caked on, and very thick. Unfortunately after about 2pm, the house shades it, so production drops significantly.

Another reason to Ground mount, lots of starlings nesting nearby and when they are nest building they rest on the top ridge of the panel and poop. In april/may I clean then every 10 days, could not do that if they were on a roof.

You should mark the point on your chart when you hosed them down.
The act of hosing them would also cool them and could be partially responsible for the increase in yield.
Also a graph of the solar intensity throughout your experiment would be helpful.

I did an experiment by letting cool (53 F) water trickle over the panels, cooling them and got similar results.

Do you use a squeegee etc also?

McKravitts said:

You should mark the point on your chart when you hosed them down.
The act of hosing them would also cool them and could be partially responsible for the increase in yield.
Also a graph of the solar intensity throughout your experiment would be helpful.

I did an experiment by letting cool (53 F) water trickle over the panels, cooling them and got similar results.

Click to expand...

I hosed them down at 7am, still 65*F outside, and pretty much before all production. So it is a pretty good comparison.

RyGuy said:

Do you use a squeegee etc also?

Click to expand...

Nope, just the hose with a little pressure nozzle to get some distance. All I was doing is getting debris off. I didnt have much, if any bird poop.

McKravitts said:

You should mark the point on your chart when you hosed them down.
The act of hosing them would also cool them and could be partially responsible for the increase in yield.
Also a graph of the solar intensity throughout your experiment would be helpful.

I did an experiment by letting cool (53 F) water trickle over the panels, cooling them and got similar results.

Click to expand...

A chart of ambient air temperature over the time frame would also be helpful.
I have no doubt that cleaning can make a significant improvement in solar production and that is not well publicized.

Well, I may have to brush off snow during winter,
but at least I don't need to worry about cleaning them during summer - it rains every 3-4 days and does the cleaning for me!

Lt.Dan said:

I hosed them down at 7am, still 65*F outside, and pretty much before all production. So it is a pretty good comparison.

Nope, just the hose with a little pressure nozzle to get some distance. All I was doing is getting debris off. I didnt have much, if any bird poop.

Click to expand...

That's what I do as well. Easy to do as mine are on ground mounts. Seems to perform better soon after.

For a week, then like your car ... OK, OK, I did douse the ones in the back a day or so ago. I used a camper brush to get the bird sh*t off.

ksmithaz1 said:

For a week, then like your car ... OK, OK, I did douse the ones in the back a day or so ago. I used a camper brush to get the bird sh*t off.

Click to expand...

Back here in the woods I have that also, usually don't bother with a brush unless its real bad.

Water around me
And the solar panel are about my middel Hight from my body.
Easy to clean .
Just a bucket of water over it and done.
The boat cleaning is more work.