Scratches on PV Panels

[Reddy]

Hi,

Just had 16 PV panels fitted last week and all seemed to go well, but have just noticed a few of the panels have quite long scratches (see images) on the top of them (scaffolding is still up, so I went up for a look)! I can really only see the bottom row of panels and 3 out of these 8 are scratched. Is this likely to effect the efficiency of the panels and do you think its reasonable to expect the company to replace them?



thanks in advance for any help.

David

 

[whinmoor]

It's not ideal. Imagine if you spent £10k on a new car and it turned up like this. It might drive ok but would you be a happy bunny? I'd be withholding final payment until sorted although with the FiT rush, you may find your hands are tied. Better to act now otherwise the scaffolding will disappear and cost/hassle will increase.

 

[Reddy]

Thanks for replying. Unfortunately, the final payment was made last week after installation so I could get the MCS Cert and get everything sent off for the FIT application. I only went up to have a look today out of curiosity and that's when I noticed the scratches. I will get in touch with the company and see what they have to say.

Does anyone know if this will any effect on power output?

 

[whinmoor]

Power output initially wouldn't be much affected but I expect the scratched panel will degrade quicker and the anti-reflective coating may well be compromised. Are the scratches definitely on the outside of the glass? Can you feel them when you run your fingernail across them?

 

[Reddy]

Hi, the scratches are on the outside of the glass.

 

[and]

I had the same: 10 out of 16 panels scratched on my install 3 Nov.

Installer replaced one panel that had a 'stone chip' in it, wasn't keen to replace any of the scratched panels though.

It's difficult to know what to do ... I got a cheap install (10K) and that was the week all the panic had kicked off - lucky to get an install at all, lucky to get REC 245 panels and Power One 3600 ... I do remain unhappy about the scratches though.

The scratches were (I'm 99.9% sure) caused by installers stacking them flat up on the scaffolding with just one person handling them and effectively dragging the aluminium frame of one panel across the glass of the one below ... I thought at the time it was a crap way to be dealing with the panels.

Now all the panic is over, perhaps I ought to chase up the installer ... I was being perhaps a bit too kind to him, knowing that they were working under a lot of pressure trying to get materials and installs fitted in before the deadline.

I'll pop up on the roof on a dry day and see if the scraches have weathered away at all.

 

[Guest123]

Would you be happy taking delivery of any other item of 'brand new' equipment with dirty great scratches on it......I certainly wouldn't.

 

[moggy1968]

it will compromise the performance of the panels and now the coating has been compromised water and frost will get in, causing it to lift even more. degredation of the panels will be significantly accelerated.
In ten years time the condition and performance of your panels will be significantly less than you would expect (maybe sooner)
it just isn't acceptable.

 

[solarcat]

I really do not agree that the scratches can in any way affect the panel's durability. All MCS accredited panels are encapsulated in very thick glass and a scratch isn't going to make water go anywhere near the PV cells.

What may happen however is that the scratches may cause some very slight shading onto some cells, and even if only a couple of cells experience some shading the output loss may not be insignificant as cells are connected in series and so are the panels..,

I would suggest you ask for a replacement. If the modules were already scratched when the installer received them, the module warranty should cover that.

 

[moggy1968]

does shading afect the performance of a panel, yes, do scratches inpair the performance of a panel, yes, in exactly the same way. It's not to do with the cells, it's to do with the transmittence of light. Solar panels (good ones anyway!)have hydrophobic and antireflection coatings on them to improve the transmittence of light (by about 8%) and the panels ability to self clean. If you damage this coating water can get underneith. this then causes lifting of the rest of the coating, causing a delaminating effect over the surface of the panel. This forms crazing of the coating which will block the light transmittence and will become more and more extensive as more time passes. The effect accelerates with time as the affected surface area gets larger. superficial scratches that don't penetrate the coating you'll get away with, but deeper ones are a problem. by deep bear in mind the coating is nanometers thick (thats 1.0x10 to the power of minus 9)
but then what do I know, I've only got a degree in optics!

 

[moggy1968]

coincidently my mate rang me just after I posted so I asked him. He confirmed the above.
He's a doctor of physics specialising in thin films technology, probably one of the top 3 specialists in his field in the world so I think I'll take notice of what he says!

 

[and]

Thanks moggy1968 for the info concerning scatches. I've just written to my installer now the busy period is over to see what he advises.

Reddy - can you keep posting to let me know how you are getting on with dealing with the scratches on your panels.

I include a photo of one of my nine scratched panels

 

[moggy1968]

eek, thats bad!!

 

[Reddy]

thanks moggy for the information. I have emailed the company today and will keep you informed as to the outcome.

 

[and]

Sent the following email (and photo of a scratched panel) to REC headquarters in Norway yesterday (no UK office):


“Please could you advise me on whether an 'alloy scratch' on my solar panel (caused by the aluminium frame of one panel being slid over the glass of another panel) will have any of the following adverse effects:

- void the 25 year output warranty
- damage the integrity of the anti-reflective coating
- be likely to cause the panel to degrade/lose output quicker than an unscratched panel

Please could you also confirm that indeed the anti-reflective coating is on the exposed side of the glass.”


A reply came back today:


“Dear Sir,

Thanks for contacting us.
No, this small scratch will not affect your product warranty.
Moreover, we find it very unlikely that this scratch will cause the module to degrade over time.
So nothing to worry about.

Regards,
Christian Heinlein”
Christian Heinlein Ph.D. | Senior Product Manager | REC Solar AS
Mobile: +47 928 28 546| Fax: +47 67 57 44 99
www.recgroup.com