solar panel started to melt, my fault or faulty solar panel

fodbrothers

So I was just doing a day test before installing my panels correctly and I has 
2 groups of 2 (2S2P) I have more but I was just doing a simple test at the moment 

4 x 100 watt panels https://www.amazon.co.uk/gp/product/B07YKQZ2N3/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I have a 40A controller https://www.amazon.co.uk/gp/product/B07FRM17DM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
12v battery Trojan 1275

I had it going through most of the day without a problem then suddly a spot on the brand new solar panel (just one of them) started to melt
I was within the limitations but 1 solar panel set did start to get some shading which about 1.5 hours in I noticed it.
any ideas if this was a fault of mine or just a bad solar panel 

fodbrothers

MichaelK

That's bizarre!  I'm guessing that there must be a defect in the silver conductor, and it started acting like a fuse, getting hot enough to melt.  I would say it's a flaw in the panel.

fodbrothers

thank you for your reply MichaelK I will carry out the same test again tomorrow and hope it is just the one panel. (obviously not using that one) I will update on here my results. just in case someone else has the same issue as I did. 
I will check here again before doing the test just in case someone thinks of anything. 
thanks again for your reply

mcgivor

Are you able to return them? Flexible panels are reputedly inferior to ridgid glass ones, if they could be returned that would provide an opportunity to make the switch, unless it's impossible to use ridged of course.

littleharbor2

Very likely the flaw won't affect the output in the event you have a big issue in the returns process.

fodbrothers

I have been extreamly lucky and getting replacement and a refund woop woop. 
Mcgivor. Thamks for your input as these are on a greenhouse the weight is a bit of an issue especially when I have built a wooden tilting frame. 
Littleharbor. Question for you, if I hadn't returned the panel if it was reconnected wouldnt the imperfection carry on arcing and burn an even bigger hole. 

BB.

You are correct... When you see signs of overheating, arcing, melting, hole in rear/front let moisture in--With more problems, etc... There are major problems and eventually the panel will fail and possibly start a fire (worst case).

-Bill

fodbrothers

Thanks BB for replying. I would be with you on that one. 
With regards further testing with a new panel in place of the broken one. I have not occurred any problems as of yet. 
I am doing another test today to see if any problems happen but I'm feeling confident it was a panel issue.
Thanks again for all the replies, you guys are amazing. I'm so happy to have found this forum and the amazing support.

littleharbor2

fodbrothers said:

I have been extreamly lucky and getting replacement and a refund woop woop. 
Mcgivor. Thamks for your input as these are on a greenhouse the weight is a bit of an issue especially when I have built a wooden tilting frame. 
Littleharbor. Question for you, if I hadn't returned the panel if it was reconnected wouldnt the imperfection carry on arcing and burn an even bigger hole. 

 Good question. It may have grown a bit more. Was there any evidence of burning on the backsheet? I agree with BB as to the backsheet becoming damaged and allowing moisture to enter. Seems odd that this happened right away. Was this panel possibly over flexed in the area of the damage? Never been a fan of flexible panels. Did you, by chance, test the output of this panel compared to another panel? 

 I have handled  thousands of used panels over the years and have seen, possibly hundreds of these type of flaws in panels. While they may look bad the area shouldn't continue to grow and will likely have minimal effect on output provided the flaw remains localized and the tabbing remains intact. Each individual cell has many dozens of traces for the current to flow through and the arcing, if that's what this is, from what I've seen wouldn't have spread across the cell. Then again, just my opinion and observation.

It's great that you were able to get a full replacement and obviously the best way to go. Your small system size is the only reason I would even give the reply I have.  My only other suggestion for the future would be to find a way to support conventional, glass and framed panels they should give you reliable service up to and beyond the life of their warranty.
 

fodbrothers

Hi littleharbor2 
Thank you very much for the reply
The panels are awful I have now had 3 panels burn in places and 1 misshapen 
Very crazy. 
I will be going to glass ones 
Do you recommend any. I will be buying from amazon UK 
I am also a little confused with max system fused. 
I always thought this was a limitation of the panel and some just say it's not but you need to put a fuse in.
A bit of clarity on this would be great. 
I don't want to make any mistakes 


Thanks again for all your guys help 

fodbrothers

mike95490

have you tried to roll or curl those panels.  they still have silicon wafers that don't flex

fodbrothers

no Mike, I have tried to keep them strait as possible. 

Photowhit

I was surprised to learn thin silicon wafers do flex, I don't understand it myself as I would think a crystalline based material would easily fracture.

https://www.electrochem.org/dl/ma/203/pdfs/1014.pdf

BB.

One of the issues with silicon cells (as little as I understand/recall), there can be defects in the cell where (I guess) the breakdown voltage is lower in spots, vs the rest of the cells. If you put the panel under sun (and do not draw current for charging?), those defects can overheat and cause damage to cell and surroundings.

Of course, other connection problems (solder failures, delaminiation, water corrosion, cracks in silicon, etc.) can also cause hot spots.

-Bill

littleharbor2

fodbrothers said:

Hi littleharbor2 
Thank you very much for the reply
The panels are awful I have now had 3 panels burn in places and 1 misshapen 
Very crazy. 
I will be going to glass ones 
Do you recommend any. I will be buying from amazon UK 
I am also a little confused with max system fused. 
I always thought this was a limitation of the panel and some just say it's not but you need to put a fuse in.
A bit of clarity on this would be great. 
I don't want to make any mistakes 

Thanks again for all your guys help 

fodbrothers said:

Hi littleharbor2 
Thank you very much for the reply
The panels are awful I have now had 3 panels burn in places and 1 misshapen 
Very crazy. 
I will be going to glass ones 
Do you recommend any. I will be buying from amazon UK 
I am also a little confused with max system fused. 
I always thought this was a limitation of the panel and some just say it's not but you need to put a fuse in.
A bit of clarity on this would be great. 
I don't want to make any mistakes 


Thanks again for all your guys help 

 Most rigid panels these days are pretty much the same, quality wise. Look at the brand names in the forum hosts store. They don't sell junk. There are some poor quality ones in the small output range. Look for a 20+ year warranty and stay away from Harbor Freight panels. (probably not available in the UK). Personally, If I had to pick a favorite brand I would chose Kyocera. I have had many interactions with them over the years and they are very upstanding when it comes to their warranties.

 The max fuse rating is for each panel, or string of panels. You only need over current protection in systems with 3 or more strings. While not required, it's still a good idea to have a fuse , or better yet a DC rated circuit breaker on each string. This gives you the ability to shut down any one or all strings for system maintenance/shut down. etc.

fodbrothers

so would 2 of these be ok https://www.itstechnologies.shop/collections/solar-panels-buy-online/products/320w-ja-solar-mono-percium-lw-black-frame-solar-panel
im a little confused with regards to controller limits
https://www.amazon.co.uk/gp/product/B07FRM17DM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
as the max charge power and the max pv array. 
obviously I dont want to make a mistake. 
cheers in advance again

littleharbor2

The nice thing about MPPT controllers is that you can over panel them and they will merely limit output to their rated output current. I would run these in parallel if you are charging a 12 volt battery, series, if a 24 volt battery.

Here's something you might like from the mfg. of that controller.

fodbrothers

Ok great 
Thanks for the info. 
I'll get them panels I just wanted to know what the difference was. 
Will it limit the charge then ? 
I wouldnt get near them limit (Watts ) in reality anyway 
I just wondered what was the difference 
And of the panels are good 
Yes its a 12v battery 

littleharbor2

fodbrothers said:

Ok great 
Thanks for the info. 
I'll get them panels I just wanted to know what the difference was. 
Will it limit the charge then ? 
I wouldnt get near them limit (Watts ) in reality anyway 
I just wondered what was the difference 
And of the panels are good 
Yes its a 12v battery 

A40 amp controller will not charge over 40 amps. Solar panels rarely put out their rated power. I doubt you will ever see 40 amps anyway from two of those panels.

naimisha123

Return them and buy a new solar product. I bought from qwik batteries 3yrs back. Still its on condition. You can go for solar panels from them and also they even supply solar batteries.