Does anyone wash their PV solar panels?

[Deleted User]

Hi, just moved to a house with solar panels and having fun playing with energy monitors. Quick questions - does anyone wash their panels? How, DIY, window cleaner or professional service? Is it worthwhile?

gefnew

Hi mmmmikey
Yes every year in march with rain water.
If you use tap water the chemicals will leave stains and marks on the panels. also be careful that you use something that is not abrasive.
most of the time the rain will keep them clean.
But if you have trees or a lot of bird poo it is worth taking a look now and again to see if you have a problem.
regards
gefnew

Cardew

There have been several threads on this over the years, with mixed opinions.

As I understand the Rent a Roof firms don't routinely wash panels, it is probably not required for the majority of cases.

reeac

It will depend on the pitch of the roof. Ours are at 45 degrees which is fine but I have read somewhere that below maybe 30 or 35 degrees rain alone won't keep them clean.

Martyn1981

reeac wrote: »

It will depend on the pitch of the roof. Ours are at 45 degrees which is fine but I have read somewhere that below maybe 30 or 35 degrees rain alone won't keep them clean.

Mine are at 20d and 30d pitches, I give them a quick clean with an extendy pole thingy every 2 or 3 years, but it doesn't seem to make much difference.

The advice from the Energy Saving Trust is:

Solar PV needs little maintenance – you'll just need to keep the panels relatively clean and make sure trees don't begin to overshadow them. In the UK panels that are tilted at 15° or more have the benefit of being cleaned by rainfall to ensure optimal performance. Debris is more likely to accumulate if you have ground mounted panels.

EricMears

At 17.5 deg slope, our panels are probably shallower than most but still seem to stay reasonably free of dust etc.

I have occasionally hosed them off (I can get to the roof fairly easily and because it's so shallow can stand on it OK) but have never noticed a huge increase after doing so.

coffeehound

Do panels have a non-stick coating?

Dave_Fowler

coffeehound wrote: »

Do panels have a non-stick coating?

The panels used on my house roof (Schuco) had a notice with them telling the installers not to touch the surface. These panels have remained exceptionally shiny and clean during the 7 years they have been on the roof. Those fitted to my garage roof (Suntellite) did not have the warning message. Over the past 5 years they have slowly got a film of algae, particularly along the lower 3rd of each panel, When I had an optimiser fail earlier this year I cleaned two of the panels so that I could compare the outputs between these two and the remaining 10. (It's a SolarEdge system with individual panel monitoring). Surprisingly there is no measurable difference between the cleaned and the dirty panels - less than the manufacturing variations between panels.

Dave F

Martyn1981

Dave_Fowler wrote: »

When I had an optimiser fail earlier this year I cleaned two of the panels so that I could compare the outputs between these two and the remaining 10. (It's a SolarEdge system with individual panel monitoring). Surprisingly there is no measurable difference between the cleaned and the dirty panels - less than the manufacturing variations between panels.

Dave F

Cheers, that's good to know as I'd have wrongly thought small difference but noticeable (just). Guess I'll stick with a quick 3 yearly wash ..... if I can be bothered.

[Deleted User]

Thanks all, a useful cross section of replies - I expect this has been covered before but my forum searching skills weren't up to finding this info

HolmesM

That's a good question

Generally, they clean themselves with the rain ...