Greetings! Semi Flexible Fix/Replace??

[Wanderman]

Greetings all!

I wish I had found this forum 2 years ago when I started my research for panels and a charging system for my rather odd little RV.
Ah, well...hind sight is always 20-20!

Here's the current issue:

I have a full solar charging system installed that was working great until now. The panels were manufactured for me, to size.by a company in China. (ppgardon@gmail.com)

They are the custom semi flexible panels I ordered from china a while back.

http://www.thewanderman.com/2011/11/better-solar-charging-mouse-trap-part-1.html

for info and pictures.

I looked VERY closely at the panels themselves and can see no breaks in any leads or modules.

They have a junction box affixed to the upper side of each panel with a blocking diode on the positive terminal . Each one has it's own independent neg/pos pair going down to it's own fuse (positive side) and neg stud. From there it goes to the morningstar.

This was working YESTERDAY. And the past 60 days of log from the controller shows normal volts and amps. I am at a loss. I have no idea what to try at this point and removing these panels will be VERY difficult to do.

We did have some strong rain yesterday, but all the junction boxes are dry inside. It's frustrating to see the controller show NIGHT in the middle of the day.

I was just testing. I removed the positive lead from the junction box terminal and tested volts at the panel's pos/neg leads. Nothing at all. On all three panels. What are the odds? I tested before and after the diode AND for amp both with a direct connect and a clamp on. Nada.

Seems to me it's a wiring disconnect, likely the same place or similar on all three, but where?

Sent an email to the manufacturer....maybe they will reply.

*sigh*

Since the measurements are so odd, most standard panels wouldn't fit. Hence the custom build.

roofmapDone.jpg

The existing panels worked great when installed. They may have failed one at a time over the last few months, bu the last one failed without any RV movement at all.

Aero_Roof1.jpg

I am at a loss. These will be VERY difficult to remove. Ideally a fix would be best, but barring that I'd like to replace them with something more reliable. Preferably semi-flexible or thin so I don't have 30-40lbs per panel on the roof. Unisolar type panels are too few watts per square meter so they are out. I have 450 watts now so that or greater would be the best.

HELP!

Rich "The Wanderman"

[inetdog]

I was just testing. I removed the positive lead from the junction box terminal and tested volts at the panel's pos/neg leads. Nothing at all. On all three panels. What are the odds? I tested before and after the diode AND for amp both with a direct connect and a clamp on. Nada.

Seems to me it's a wiring disconnect, likely the same place or similar on all three, but where?
The existing panels worked great when installed. They may have failed one at a time over the last few months, bu the last one failed without any RV movement at all.

You have done all the right testing. If a detailed (magnifying glass even) inspection of the panels does not show any cracks in the cell material or the bus wire, then you are pretty much out of luck.

If you can see the cell-to-cell tab wiring and can try using a needle-tipped probe to connect to it with your meter (with the plan of sealing the holes in the top coating later) then you may be able to track down the break and somehow patch around it. You might end up with the output voltage of the panel down by a volt or so if there are bad cells.

I agree with the suspicion that the panels have been failing one at a time without you noticing. The other possibility would be something like a lightning strike (!) or other external event that took them all out at one time.

You said that they are semi-flexible. Possibly thermal expansion and contraction with the backing glued down has stressed the inside of the panels. That would be consistent with it failing overnight.

[SunEagle]

While the thin film flexible type panels have a shorter life span then the metal frame type these should have lasted much longer then you have had them.

They may have failed one by one due to heat stress and then water entering a weak point in the panel. Since the last one failed after a rain storm there might be some type of tracking between the pos and neg terminals causing a short.

The entry point may be on the back side which would make it much harder to find. Are these panels totally sealed to keep water out from behind it?

[Wanderman]

Yes, they are completely sealed from the factory. Even then I added additional sealant around the edges, still intact. I can see no water ingress, nor delamination. The back substrate is anodized aluminium that is sealed against the roof fiberglass with a 3M paralastic adhesive that allows for expansion. The only weak point I can see is the junction boxes.

Rich

[inetdog]

Yes, they are completely sealed from the factory. Even then I added additional sealant around the edges, still intact. I can see no water ingress, nor delamination. The back substrate is anodized aluminium that is sealed against the roof fiberglass with a 3M paralastic adhesive that allows for expansion. The only weak point I can see is the junction boxes.

Rich

What is the material on the front side of the panels, over the cells?

[Wanderman]

Here are the specs for one of the panels.

Statement of Raw Material for the Module
No. Item Specification Quantity Unit Material Remark
1 Silicon Solar Cell 156×103 72 sheet Mono-crystalline
2 EVA 1956×660 2 sheet
3 Back Film 1956×660 1 sheet Aluminium
4 Cable 4mm2Double layer isolated cable 1 piece Anti-UV “Positive” 0.9M (Black) “Negative”0.9M (Black)
5 Plug 40A 1 pair Anti-UV
6 Junction 1 set PPO Hermetically sealed
7 By-pass Diode 10A10 3 piece


Ethylene-vinyl acetate I believe.

RIch

[inetdog]

Ethylene-vinyl acetate I believe.

RIch

That means that in a pinch (which you may be in!) you can try carefully removing or penetrating the EVA film for testing and possible kludge repair.
Zero volts, zero amps really does come down to an open connection for whatever reason.
If there is visible corrosion at the base of the + and - bus leads, testing just inside the panel from there would be a good start. Especially if you can see undamaged bus wire further back from the penetration.

[pjefferies]

Did you fix the panels?

Here are the specs for one of the panels.

Statement of Raw Material for the Module
No. Item Specification Quantity Unit Material Remark
1 Silicon Solar Cell 156×103 72 sheet Mono-crystalline
2 EVA 1956×660 2 sheet
3 Back Film 1956×660 1 sheet Aluminium
4 Cable 4mm2Double layer isolated cable 1 piece Anti-UV “Positive” 0.9M (Black) “Negative”0.9M (Black)
5 Plug 40A 1 pair Anti-UV
6 Junction 1 set PPO Hermetically sealed
7 By-pass Diode 10A10 3 piece


Ethylene-vinyl acetate I believe.

RIch

I have the same style semi-flexible panels (two x 100 watt) also from China and mine also failed due to vibration/heat after 15 months. Have removed mine (which was a pain as were glued on) and am replacing with rigid panels mounted with brackets so 2cm air gap underneath as this approach seems more reliable for campervan use. Can't get supplier to replace semi-flexible panels so curious to know whether you managed to repair yours? There not the cheapest of things so worth repairing them for my shed if I can!

Thanks.

[Wanderman]

I know this is an old thread, but here's additional information.

It seems that the anodizing on the aluminum substrate was done poorly. Th e aluminum began to arc-contact the bottom of the modules and the whole shebang is kaput.

I've spent MANY months putting together a U.S. sourced replacement. After much testing and tweaking...here is the story of the odyssey:

http://www.thewanderman.com/2013/10/new-solar-better-than-old-solar-part-1.html

Hope this helps everyone out.

Rich "The Wanderman"

Back off the Grid!

I have the same style semi-flexible panels (two x 100 watt) also from China and mine also failed due to vibration/heat after 15 months. Have removed mine (which was a pain as were glued on) and am replacing with rigid panels mounted with brackets so 2cm air gap underneath as this approach seems more reliable for campervan use. Can't get supplier to replace semi-flexible panels so curious to know whether you managed to repair yours? There not the cheapest of things so worth repairing them for my shed if I can!

Thanks.