Do I need my inverter checked and my solar panels cleaned?

[bazza]

Hello,
My solar panels were installed in 2010 and have never been cleaned or serviced.
They are now showing signs of lichen stains according to a cleaning company.
I have 18 panels – Romag PowerGLAZ 220W (3.8Kw) Polycrystalline Silicon Photovoltaic.
The company that I have asked for a cleaning quote has said:

1. I will benefit from better FIT payments and
2. That my type of panels are only as efficient as the ‘dirtiest’ panel.

Does anyone know if either of these statements is true?
Also, do I really need then cleaned?
Many thanks for any comments.

[SunEagle]

Hello bazza and welcome to Solar Panel Talk. Some people here have cleaned their panels in the past. Depending on how high they are mounted will help determine how to clean them.

[bazza]

Many thanks for the reply SunEagle - Some of my panels are quite high and a 'cherry-picker' is needed to get to them - but my main thoughts are: is there a real benefit from cleaning and are the panels easily damaged?

[SunEagle]

Many thanks for the reply SunEagle - Some of my panels are quite high and a 'cherry-picker' is needed to get to them - but my main thoughts are: is there a real benefit from cleaning and are the panels easily damaged?

As I said some people have cleaned their panes and have gotten an increase in output but depending on where they are mounted and how high they are can be expensive and out cost the energy output that the cleaning gets you.

Hopefully others that have gone through what you are now experiencing will comment.

[bazza]

Thanks again for your input SunEagle - and, yes, hopefully there may be other comments.

[DanS26]

Some of my Kyocera panels have been up and producing for 14 years. I have never cleaned them. At some points in the year I find dust build up that will harden into a small line of sludge at the bottom of each panel but when wet weather comes it is washed off. Also I have noticed lichen growth but when the hot dry season arrives it disappears.

I have not seen a falloff of production in 14 years per PVWatts and using 0.71% degradation factor for the poly crystalline panels. I'm located in the Midwest and rainfall can be heavy at times. I think it depends on your geographic location and the tilt of your panels. My main arrays have a 32.5* tilt for my fixed mount and for the latitude here.

[sdold]

Hi Bazza, I work for the State of CA and we have a few mountain-top solar sites. We've never cleaned any of them that I know of, and many of them have been up for well over 20 years. Whatever dust accumulates on them is gone after the first rain. I've never seen lichen on panels though, I didn't know that was a thing until I read this thread.

I had a noticeable coating of brown dust on my home array once, and when I cleaned one panel I immediately saw a 5% improvement in that panel. It didn't seem worth bothering to go on the roof to clean them all, and after the first rain, they were clean again.

We installed the panels in my profile pic in 2003 and they still put out 80-90% of what they did when new, and the dropoff over the years has always remained fairly linear (no steeper drop off in later years) so unless you've seen more than that or there is stuff that isn't gone after a few rains, I probably wouldn't bother cleaning them. I don't know about "servicing", we never do a thing to ours. They suffer through a lot of heat and harsh winters, too.

[bazza]

Many thanks to both DanS26 and sdold for your experiences and advice, it is much appreciated. I now think I have a good idea as to which way to go.

[DanS26]

............... I've never seen lichen on panels though, I didn't know that was a thing until I read this thread.

Here is a pic of lichen growth on an older panel. I think it is growing on the sealant rather than on the aluminum frame or the glass. Has no effect on performance. Very colorful if you zoom in.

IMG_1459(2).jpg