Fexible panel burnt under the sun

[ramstein]

Hi,
I guess my panels won't survive for a very long time if they already have this kind of burn after a few days under the sun. Around 30°C in France, but on the roof I think temperature goes way higher. I didn't glue them, just used screws to fix them, there is a bit of air under them but not much. For the moment they are working well though.
Anyway, chinese qualitat...

 

[sunshine_eggo]

While this might be a sign of shoddy workmanship, flexible panels do not have anything near the durability of solid frames.

In free air with ample backside clearance and a breeze, the panel is likely to hit 40-50°C in 25°C ambient. Reduced clearance or higher ambient means they can go way higher. This decreases performance and light.

The only thing I would consider flexible panels are for a "deployable" array in PVC frames like this:

Cheap Dual Flex Panel Mobile/Tilting Stand

Here’s a super lightweight and cheap adjustable stand design that I use for 100w flex panel pairs. Each unit costs

diysolarforum.com

 

[SparkyJJO]

That looks like bird poop.

 

[sunshine_eggo]

That looks like bird poop.

Definitely worth a clean to confirm!!!!!

 

[ramstein]

While this might be a sign of shoddy workmanship, flexible panels do not have anything near the durability of solid frames.

In free air with ample backside clearance and a breeze, the panel is likely to hit 40-50°C in 25°C ambient. Reduced clearance or higher ambient means they can go way higher. This decreases performance and light.

The only thing I would consider flexible panels are for a "deployable" array in PVC frames like this:

Cheap Dual Flex Panel Mobile/Tilting Stand

Here’s a super lightweight and cheap adjustable stand design that I use for 100w flex panel pairs. Each unit costs

diysolarforum.com

Yes.. But I wanted to go stealth. In France it's not easy to have visible panels on the roof, you can't stay in your van so better be stealth.

That looks like bird poop.

I thought too at the begining but I touched it and it doesnt feel like bird poop, more something like cracks. I'll check again to be sure lol

 

[sunshine_eggo]

I thought too at the begining but I touched it and it doesnt feel like bird poop, more something like cracks. I'll check again to be sure lol

EW! YOU TOUCHED IT!!!!????

 

[ramstein]

EW! YOU TOUCHED IT!!!!????

haha I'm a courageous man Well the panel is warped in this area so I guess it's really the sun that burnt it. But I'll check again you made me doubt

 

[sunshine_eggo]

haha I'm a courageous man Well the panel is warped in this area so I guess it's really the sun that burnt it. But I'll check again you made me doubt

Wasn't me! Was this guy:

That looks like bird poop.

I saw nothing but some kind of defect... until bird poop was mentioned...

 

[Solar Guppy]

If you look at the image, you will see the cell has fractured likely causing a short circuit. There is no such thing as flexible silicon wafers and bending them will eventually always result in damaged cells
.

 

[ramstein]

If you look at the image, you will see the cell has fractured likely causing a short circuit. There is no such thing as flexible silicon wafers and bending them will eventually always result in damaged cells
.View attachment 163889

wow I didn't even see this. that's strange because I didn't bend the panels they are put flat on my roof. I have to investigate... The sun warped this area so it probably caused the damages you showed. I'm going to test the panel to see if it still delivers

 

[SparkyJJO]

If you look at the image, you will see the cell has fractured likely causing a short circuit. There is no such thing as flexible silicon wafers and bending them will eventually always result in damaged cells
.View attachment 163889

But they said flexible! C'mon man!

 

[Aussieguy]

new style of panel
you can bury it to release the attached fertilizer

 

[Solar Guppy]

To my eyes, the clouding is the result of shorting the broken cell is causing, if this was in series or parallel with other solar panels, it would likely cause a fire instead of the smoke under the laminate.

 

[sunshine_eggo]

To my eyes, the clouding is the result of shorting the broken cell is causing, if this was in series or parallel with other solar panels, it would likely cause a fire instead of the smoke under the laminate.

If it's not poo, this makes the most sense. If it's poo, then those misalignments look really scary anyway.

 

[chrisski]

In 105 degree sunny weather I’ve measured my flexible panels at 155 f (68 C).

I keep them covered when not in use.

 

[ramstein]

To my eyes, the clouding is the result of shorting the broken cell is causing, if this was in series or parallel with other solar panels, it would likely cause a fire instead of the smoke under the laminate.

this panel is in serie with 2 others, they are fine hopefully. But I'm concerned about safety yes.

 

[0truck0]

Yep.
I give the same advice over and over...
You need airflow under the panel to help cool them. I had a fiberglass camper that I used the flex panels on as the glass ones would have taken away from the sleek aero shape. I still needed airflow however under panels.

I cut corrugated plastic sheets (like a yard sign) to the same size as said cheapo garbage flex panel and put that under the panel. It only added a little height (worked for me) but let air freely flow under the panel, though a bit restricted. I did not block any of the flutes, so each channel was open to the air. I used VHB tape to hold it all down, only putting the tape to cover one end of the flutes, and left most flutes open on both sides.
I ended up selling camper before I could give it a long-term review, but feel confident this reduced temps under the panel.

Flex panels are flexible, but think of them as something you flex only ONCE, and never again. Repeated flexing can break things.

 

[Tomthumb62]

Not all flexible panels are equal. Ours are mounted on a wood roof that’s sealed with painted canvas, so even in 40C temps, it stays cooler than a metal roof. Our most recent flexible panels are the 100W Sunpower ones (by Maxeon) and they’re clearly better designed. I expect them to last a good long while. Our original ones are cheap ones from WindyNation that are surprisingly still working 4 years later, but our wood roof and covered storage for 6 months of the year probably help a lot.