Scratches on PV Panels

[moggy1968]

ok, well that sounds reassuring!
still, given the example above I wouldn't want a new car with a scratch on it!

 

[yorkshiremike]

Are they actually scratches? It depends what the anti-reflection coat is (some are quite hard), but glass is a lot harder than aluminium and you can't usually scratch it with aluminium. However, you can 'draw' on glass with aluminium and leave a thin layer of aluminium on the glass. It's a common problem where aluminium pots and pans are used on glass hobs. Usually solution is to leave some dilute bleach on the mark for a hour or so (which corrodes the aluminium) then rub off - not sure I'd do this on a panel though unless knew that the bleach wouldn't attack the AR coat and it would need keeping off the aluminium panel frame.

 

[moggy1968]

it will attack the AR coat. best bet might be spectacle cleaner!!
It is possible to scratch the coating not the glass. the coatings aren't as hard as the glass.

 

[deeyup]

Try methylated spirit

 

[and]

Certainly on my panels the 'scratches' are indeed a thin layer of aluminium.

The installer wanted to clean these off using a stanley blade but I pointed out on a downloaded REC maintenance sheet that such things were on the DO NOT list.

If the scratches are as the Norwegien REC man says, not likely to degrade the integrity of the panel, then perhpas they are best left.

It is indeed like having a scratch on a new car, it shouldn't be there.

 

[moggy1968]

yep, we use meths in the optical industry for cleaning coated lenses so that should be ok, just don't use it on ploycarbonate!!

 

[SolarCity]

If I were you, I'd date and keep a copy of that email they sent. If there ever is an issue, it'll give you some leverage.

 

[Reddy]

Hi All, Just an update. Top marks to the installation company, they have agreed to replace the scratched panels

 

[Worcester]

@moggy, I read your comments and whilst we all now about the efects of shading - do you have some evidence with regards to your claims of long term detriminetal effect - e.g. case studies, published papers etc that I could read?

And yes I've talked to my brother who actively works in the field that you qualified in and abandoned

 

[moggy1968]

The effect I have seen are specifically on optical lenses where you see a pattern of delamination along the dges of a scratch on an AR coat. you don't see it that often because by and large spectacle lenses are replaced every couple of years or so but I have seen it on older lenses and those with inferior coatings from companies that suggest you should have gone to, but I think maybe you shouldn't!
Clearly any marking on an optical surface will affect the transmission of light through that surface, be it dirt, scratches, or shade (although not strictly a marking on the surface.

 

[and]

Reddy - Very good news that you are getting your scratched panels replaced ... I haven't yet heard back from my installer since I emailed him a couple of days ago, but you getting your scratched panels replaced at least sets a precedent.

I think logic dictates that what moggy1968 points out about degredation of AR surfaces is correct, and it concerns me that fifteen years down the line these scratches might indeed have caused degredation.

It is an expensive and long-term investment that ought to be installed scratch free.

 

[Reddy]

Very pleased - the installation company replaced the 3 scratched panels yesterday, no questions asked. They asked me to check the new panels after they had done and they all looked fine.

and - hope you get your panels sorted. The fact my installer replaced my scratched panels without argument suggests that it was the 'right' thing to do and they were aware that scratched panels could suffer problems in the future.

 

[fiardor]

Very pleased - the installation company replaced the 3 scratched panels yesterday, no questions asked. They asked me to check the new panels after they had done and they all looked fine.

and - hope you get your panels sorted. The fact my installer replaced my scratched panels without argument suggests that it was the 'right' thing to do and they were aware that scratched panels could suffer problems in the future.

That company wouldnt be Eco-Fusion by any chance?

 

[Reddy]

Hi fiardor, no the company is not called Eco-Fusion.

 

[and]

Have had the worst one of my nine 'scratched' panels replaced, which I'm happy with.

I'll keep my eye on any degredation around the 'scratches' on the panels to see if it affects the AR coating.

It's difficult to say, but up on the roof it looked like the 'scratches' (caused by aluminium frame of one panel coming into contact witht the glass of another) may be being weathered away.

It was reassuring that REC said such scratches do not affect the 25 year warranty and that they think it unlikely that the AR coating will have been affected.

All in all, I'm just happy to have a nice system on the full FiT rate that I now feel happy about. Am looking forward to sunnier days, though am impressed that it's clocked up nearly 100kW in December!