Cleaning Solar Panels - Will it make much difference?

[Nifty]

Ok, the results so far:

I cleaned the two modules A1 and A7 at the end of day 7/21. You can see the difference here:

I took the power output from 2 days "before" (7/18 & 19) and compared it to the power output "after" (7/22 & 23).

BEFORE:
A2 was 0.3% higher than A1
A7 was 0.4% higher than A8

After:
A1 was 1.2% higher than A2
A7 was 1.1% higher than A8

So if my data and my math are correct, cleaning has resulted in a 1.5% increase in one panel and .7% increase in another.

 

[SKR8PN]

Can I ask why you compared the outputs of the cleaned panels, to the panels beside them(not cleaned). Why not just compare the "before and after outputs" on ONLY the panels you cleaned?

 

[Nifty]

Too much variability from minute to minute and day to day and no way to attribute any changes in output to cleaning unless there was a side by side comparison.

Example: Let's say that the panels are dirty in June and I clean them in July, but July has less sun hours (or is cloudy or whatever). The results wouldn't be accurate.

Having panels that had similar output over the course of a month, then cleaning just their neighbors, isolated out any other potential changes in output other than clean vs. dirty.

 

[SKR8PN]

I never gave that side of it a thought, but it sure makes sense!

 

[Nifty]

Okay, an update:

I took the output from the 35 days before cleaning and compared it to the 7 days after cleaning and here is what I got:

A1 is 1.76% more efficient since cleaning
A7 is 1.33% more efficient since cleaning

Tonight I also went out at the end of the day and cleaned A1 with a "California car duster " that I attached to a long 6 foot handle / dowel.

 

[big brown horse]

Um Nifty, have you seen our nerd confession thread.


p.s. isn't it nice when the boys play?

 

[Nifty]

I'm a data / analysis junkie!

 

[Nifty]

For my own records: This late morning I used the car duster and cleaned off all the panels except the two that are part of the test.

 

[gallant]

by the way, what is car duster?

I think that's been certain that cleaning panel will lead to more efficient sun catching.

 

[Nifty]

Wow, living on a dirt road with some vacant land near by really makes for a lot of dirty solar panels!

I haven't crunched any more data, but I went ahead and cleaned them all off tonight anyway.

I went to Ace Hardware and got a 11 foot telescoping window washing pole thingy. I sprayed the panels, used the window washer pad thing to scrub them a little, then hosed them off again.

They should be pretty clean now. Well, not as clean as when I used soapy water and a mop, but cleaner than just using a dry car duster.