[PoleKing]

So basically what you guys are saying is... The yank engineers are wrong, solar panels DO need cleaning..... but no one has any data that proves why or how much improvement it makes.

Apart from....... they look nicer    

I have seen some measurable data from my last solar panel clean. I cleaned a third of an array which was split into three sections with the outputs recorded, on-line, in real time. We compared the before and after output figures and the third that I cleaned showed no measurable improvement over the two thirds I didn't clean. An adjoining property had a smaller array fitted at the same time and also not cleaned since construction. Their clean resulted in a measurable improvement of 30% !
The difference was that my section was in a marshy field, away from the road and trees and the other section was in a farmyard, on a barn, with tractors turning underneath, lots of dust and the presence of molasses that left black, sticky streaks all over. The summary is that it seems to be the TYPE of contamination not the amount - Dust on my panels was negligible but the more agricultural waste on the others was not. The average rain frequency for the UK is every other day - California, rather less - So dust in the UK isn't going to be anything like that of CA and by comparison only, the UK could be considered self cleaning under certain conditions.

Nice post.
The 30% though-what did that ammount to in money-pro rata to monthly?
What did you charge-pro rata'd?

[EandM]

So basically what you guys are saying is... The yank engineers are wrong, solar panels DO need cleaning..... but no one has any data that proves why or how much improvement it makes.

Apart from....... they look nicer    

I have seen some measurable data from my last solar panel clean. I cleaned a third of an array which was split into three sections with the outputs recorded, on-line, in real time. We compared the before and after output figures and the third that I cleaned showed no measurable improvement over the two thirds I didn't clean. An adjoining property had a smaller array fitted at the same time and also not cleaned since construction. Their clean resulted in a measurable improvement of 30% !
The difference was that my section was in a marshy field, away from the road and trees and the other section was in a farmyard, on a barn, with tractors turning underneath, lots of dust and the presence of molasses that left black, sticky streaks all over. The summary is that it seems to be the TYPE of contamination not the amount - Dust on my panels was negligible but the more agricultural waste on the others was not. The average rain frequency for the UK is every other day - California, rather less - So dust in the UK isn't going to be anything like that of CA and by comparison only, the UK could be considered self cleaning under certain conditions.

Nice post.
The 30% though-what did that ammount to in money-pro rata to monthly?
What did you charge-pro rata'd?

I didn't really work out a proportional cost, just cleaned around 60 panels and billed hourly which worked out at about £50. They were easy enough to do and it was really my time and a fact finding exercise. The other site was cleaned by the suppliers so probably didn't work out very cost effective for the customer as they seemed to have slapped on a huge annual maintenance charge. A mile from my house we have 3 separate solar farms and a fourth under construction with talk of a fifth. People's houses are one thing but this seems to be getting out of hand !

[Dave Willis]

It's an interesting topic. I cleaned my own with hardly any measurable difference. What interests me also is how long does a clean last before the dust re settles? I would imagine in California probably about a week?

[richard jagger]

The yank engineers are absolutely correct....................In California,........................................ What for it
in our U K market were if dust and dirt were left long enough with our weather conditions would make a perfect
environment for the  growth medium for green and black mildews.
THis buildup would reduce the efficiency by   25/30% .



That sounds so good even I believe it.

On second thoughts
Don`t  feed this no cleaning imfo to your customers.

[dd]

On the Alex Wingrove picture the panels are situated on a roof that is almost flat so will accumulate more dust/dirt which the rain will not wash away. On a roof of say 45 degree pitch the rain would do a much better job of cleaning the panels.

Research I read on google basically said that it was worth cleaning panels on a flat (or nearly flat) roof but not on a roof of reasonable pitch.

[richard jagger]

To be honest if all that was true then we should not clean any conservatories and we all know how dirty they get. true or not?

[Spruce]

The local council have put an array of solar panel on a flatish roof on the school gymnasium. The council told the school that they were responsible for cleaning the panel once a year. They were also told that they had to bear the cost of installing a fall arrest system and getting an annual test certificate before anyone could use it.

Result was that the panels will produce less electricity than the costs of maintaining them.

So the council put the panels up and the school is just not going to fit a fall arrest system or have the panels cleaned. 

[dd]

To be honest if all that was true then we should not clean any conservatories and we all know how dirty they get. true or not?

Conservatory roofs are cleaned for cosmetic reasons. Solar panels can be relatively dirty without production being affected, otherwise the would probably need cleaning on a monthly basis to maintain performance.

I cleaned a single panel on a low roof which was very dusty. Went back in 2 months time to see how it compared and I could tell no difference between the one I cleand and all the others which were dusty.

[Elfyn]

I know that a lot of you are going to have a go at the source of this information, but stand back and take it for what it is - information.

http://www.ionicsolar.com/why_clean.html

[PoleKing]

The ionic post is fair enough.
The OP and that completely contradict each other. Who knows who is right.
But...
Who cares? That array is also in California.

Completely different ball game in the uk

[PAUL ERITH]

solar panel training might be helpful to some on here

 http://www.futureofcleaning.com/solar-panel-cleaning-training-thebasics.html

[elite mike]

i've had solar for around 3 years, clean them every now and again

dont notice any difference in output, perhaps i clean them to often.

[Dave Willis]

http://www.futureofcleaning.com/solar-panel-cleaning-training-thebasics.html


Is that the whole City and Guilds course there?

[Clever Forum Name]

Can't see that it has been mentioned but some contracts with solar panel installs require the panels to be cleaned once every x amount of months/years.

I do alot of solar panel cleaning now and customers have shown me the contract on installation.

Most of my customers are every 6 months.

I do agree with the loss of revenue. If they loose 10%. In one year and its
Cost more to clean them. Then they won't.

I work on my normal rates £30-40 per hour for cleaning Solars.

Assuming they are close enough I can normally do 2 arrays in about an hour = £50 usually.

The only thing I have found is using anything but an extreme pole is hard going
Due to the angle. 47ft extreme is a pleasure to clean with.

[telfordwindowclnr]

Wahey! This is an interesting topic! The article in question is now old news. In fact, a couple of weeks ago an article was published highlighting why the San Diego research is not comparable to the UK.

Google: "San Diego solar research compare UK" and you will find it.

PANIC OVER!!!

[telfordwindowclnr]

So basically what you guys are saying is... The yank engineers are wrong, solar panels DO need cleaning..... but no one has any data that proves why or how much improvement it makes.

Apart from....... they look nicer    

No, I got reams of data that has been verified by O&M departments of large solar companies. We know how much it increase in % and how much that means in the pocket of the client.

[rosskesava]

The authors of that article havn't released a peer reviewed paper of their results so as an actual scientific test or what ever you want to call it, it's worthless and doesn't mean anything much really.

[formb]

Don't clean solar panels or you will be killed.

[telfordwindowclnr]

solar panel training might be helpful to some on here

 http://www.futureofcleaning.com/solar-panel-cleaning-training-thebasics.html

nah mate. You don't need any kind of training for solar panel cleaning. It's exactly the same as windows! 
No way is that a dig Erith. It just makes me smile to see someone else saying training might be helpful. 

[G Griffin]

Cleaning windows is a waste of time, innit?
They only get dirty again.