Internal Corrosion Solar Panels

[Aussiepete]

Hi members

While cleaning my panels today I noticed areas of apparent corrosion of the wires within the cells. The system is about 2 years old and it is 1 year since I last washed/inspected the panels. Every panel has a few small areas of brown staining, similar to rust, around the wires within the cells.

I tried a search on the web for information but while there is some research being done, some photos showing similar areas of "rust staining", there were no actual articles or reports on corrosion problems within commercially supplied panels. Apparently the internal wires are made of material such s silver and so should not be showing brown rust type staining.

What experience or reports are there of internal corrosion of commercial panels or is the brown staining indicative of some other issue?

Any help or comments appreciated

Aussiepete

[Sunking]

Sounds like moisture is getting in.

[bonaire]

What is the make/model of the panel? Are they top-tier or perhaps lower-cost imports?

[Aussiepete]

What is the make/model of the panel? Are they top-tier or perhaps lower-cost imports?

Hi Bonaire

The panels are Canadian Solar CS6P215E. They are made in China. Their website says that the company was founded in Ontario (see http://www.canadiansolar.com/) and they manufacture their products in compliance with international quality standards. I suspect the CS6P series is a "budget" model but not sure what makes it a budget model.

I have 7 panels. All are showing the same patches of internal staining and apparent rusting of the wires that make up the cells.

There would have been thousands of these panels installed in Australia as they were supplied by one of our major energy companies.

The warranty on the Canadian Solar website makes interesting reading. Basically it is a return to China at your cost and pay the cost of returning the panels back to your home location after they have been repaired/replaced. We have strong consumer legislation in Australia which can't be negated by suppliers/manufactures warranties so my redress if the panels are failing will be with the energy company which supplied and installed the panels. However a key point is the issue of the so called 25 year performance warranty. I don't think these type of long term manufacturers warranties are worth anything - basically they are unenforcable.

I would appreciate some comment on this - why would the wires in the cells appear to be rusting? My understanding is that these wires are meant to be made from non corrodable metals.

I also now see in another forum that the signs of these problems are called "Snail Trails". It is true when you look at the panels that the affected areas do look like a snail has crawled over the internals of the panel.

While I was writing this I searched for "solar panel snail trails" and found this http://www.onlinetes.com/tes0512-sol...ail-trail.aspx

The really interesting point is not only does this explain the issue but the authors of the article work for Canadian Solar. Basically the article says it is a cosmetic problem which does not impact on the performance of the panels. I will have to think about that one? Comments?

[Aussiepete]

As I suspected - read this!

https://www.dorsetenergysolutions.co.uk/MyFiles/Files/snail%20trails.pdf

[Sunking]

If it is Snail Trails, it is or soon will be service affecting. It is a manufacturing defect resulting from poor quality control and not using premium grade materials.

[Mike90250]

warranty honored at Mfgs whim. Lovely!

At least my evergreens don't show on the list.

--

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[PNjunction]

Google "whirlpool snail trail" and you'll see Australian Whirlpool's long forum thread about this subject - scary indeed.

[bonaire]

Definitely lower-tier product there. I always think "China" when I hear "Canadian Solar". I'm not sure if they are Tier-3 or Tier-4. That's why I chose at least a model of panels for my system which has a replacement warranty and handled directly. Mine are SolarWorld (US-made) and seem to have a better service-model for warranty support than these Chinese joints.