PET or ETFE Solar panel

Hi,

Does anyone know how these PET or ETFE solar panels are made? What is their expected life?

Abhishek Rathore said:

Hi,

Does anyone know how these PET or ETFE solar panels are made? What is their expected life?

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So you are talking about semi-flexible solar panels.
From personal experience and lots of forum experience, these don't hold up very well.
They tend to delaminate because of heat buildup. They are also alot less rugged than glass panels with aluminum frame. This means that the cells tend to crack easily.

So in short, you should avoid them if possible. They are a waste of your money (not much cheaper than comparable glass panels, and sometimes even more expensive).
What is your use case? Do you really need flexible panels?

If you must use flexible panels, at least get ones with a good warranty and ETFE layer. PET tends to scratch too easily is considered less durable than ETFE.
They also claim that ETFE is more efficient because usually they have a special texture that in theory captures sun light from more angles.

Those come up slightly used on battery hookup from time to time. Pretty much every one of them has some level of delamination or sun bleaching / fade.

From what I understand, there's issues with heat as well. Regular panels usually have a gap between the panel and the surface it's mounted on, the flexible ones are usually mounted directly to the surface, and they get HOT.

For what they cost, and how long they last, I don't think they're worth it.

meetyg said:

So you are talking about semi-flexible solar panels.
From personal experience and lots of forum experience, these don't hold up very well.
They tend to delaminate because of heat buildup. They are also alot less rugged than glass panels with aluminum frame. This means that the cells tend to crack easily.

So in short, you should avoid them if possible. They are a waste of your money (not much cheaper than comparable glass panels, and sometimes even more expensive).
What is your use case? Do you really need flexible panels?

If you must use flexible panels, at least get ones with a good warranty and ETFE layer. PET tends to scratch too easily is considered less durable than ETFE.
They also claim that ETFE is more efficient because usually they have a special texture that in theory captures sun light from more angles.

Click to expand...

I was trying to make a small lighting solution with light weight to carry in harsh and remote location that do not have any access. So I have to design something that would last atleast 5years and be durable enough to sustain rough handling.

A.Justice said:

Those come up slightly used on battery hookup from time to time. Pretty much every one of them has some level of delamination or sun bleaching / fade.

From what I understand, there's issues with heat as well. Regular panels usually have a gap between the panel and the surface it's mounted on, the flexible ones are usually mounted directly to the surface, and they get HOT.

For what they cost, and how long they last, I don't think they're worth it.

Click to expand...

Have you used any of it? How long did it last?

Assuming you have to backpack these panels to a remote location there is really no option other than flexible.
The usual failure mode is overheating where the panel is mounted on RVs. If the panel can be supported but still allowing air circulation heat will be less of an issue. Other problems due to UV damage to the surface reducing solar yield.
In general the higher the quality ( and thus cost) the longer the service life.
There are sellers claiming high watt outputs from small flexible panels, this is not true. Expect around 150 watts per square meter of panel.
If the use is not continious , storing away from sun exposure would prolong life.
Go for ETFE, better resistance to UV.
Brands recomended,
BOUGE CIGS long profile , due to bypass diodes on each cell good performance with shading.
SOLBIAN
SUNWARE
SUNPOWER.
These may be expensive or unavailable in your location.
RENOGY may be a lowcost alternative.
It's probable the low cost panels will function for a few years, longer if not continually exposed.

Mike

Abhishek Rathore said:

Have you used any of it? How long did it last?

Click to expand...

I haven't personally used any flexible panels, but the ones I've seen that are a few years old definitely don't look nearly as good as rigid ones of the same age.

I know a lot of it has to do with how much the panels are bent and handled as well.

From Renogy:

"....In general, the flexible panels are less durable, but Renogy offers the same 5-year warranty on workmanship & 25 years on power output as their rigid panels...."

"....Heat has been an issue in the past with simply glueing down panels to the roof, because the panels need a small air gap to dissipate any heat passively absorbed by the sun...."
Although, their new generation of panels claims to have addressed this problem.

5-15 years is still a long time. Not every project needs to last for 20+ years. They have a MASSIVE weight savings over rigid panels too. It's all about what you need for your specific application.

Yes, my panels rest on open ended poly-something tubed pane for heat dissapation. What I have read in reviews mostly amazon is people are stating they are getting more than 4 years ( found a post saying 7 years to date). I think it is the brand I used, and will get a 4+ year warranty on the next set of panels I will buy. These panels do not sit in sun 24/7, rarely see the sun - only when i go camping or on the road. The output of the other 2 panels seem fine, but have not tested them in detail. If I go with Renogy, will see how long they last in comparison.

mikefitz said:

BOUGE CIGS long profile , due to bypass diodes on each cell good performance with shading.
SOLBIAN
SUNWARE
SUNPOWER.
These may be expensive or unavailable in your location.
RENOGY may be a lowcost alternative.
It's probable the low cost panels will function for a few years, longer if not continually exposed.

Click to expand...

I looked up the BOUGE, SOLBIAN, SUNWARE and SUNPOWER. All very expensive - like $300-800 for a 100W panel!! EDIT: sunpower is a reasonable $155-179, depending upon vendor.

The Renogy 100W is also ETFE film, at only $135. Will it last as long as an $800 panel? Probably not, but you could replace it about 6 times for the same price.

We currently have some WindyNation flexible 100W panels made with PET. They are now about 3 years old and look nearly new and are producing just as good as when first installed. $125/ea. But the camp trailer is stored under cover for more than half the year, so they don't see much weather or sun on the panels.

$300 To $800??

Here is a 100W Sunpower flexible for $155 https://www.amazon.com/SunPower-Flexible-Monocrystalline-Solar-Panel/dp/B077H45H3F

soylentgreen said:

$300 To $800??

Here is a 100W Sunpower flexible for $155 https://www.amazon.com/SunPower-Flexible-Monocrystalline-Solar-Panel/dp/B077H45H3F

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lol, yes I found those right after posting. But the other brands were crazy expensive.

soylentgreen said:

$300 To $800??

Here is a 100W Sunpower flexible for $155 https://www.amazon.com/SunPower-Flexible-Monocrystalline-Solar-Panel/dp/B077H45H3F

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Here's one for $755 (converted from 704 euros):

Abhishek Rathore said:

Hi,

Does anyone know how these PET or ETFE solar panels are made? What is their expected life?

Click to expand...

They are wonderful for balconies as their weight is much lower and their little flexibility allows them to absorb the wind tensions.
I put 2 in my balcony and survived one of the worst storms in many years here in the Netherlands, Europe.
Probably because they are Aliexpress panels, their yield is 70% of nominal power. Good EFTE panels I expect to yield 100% of nominal.
In the second year, they still output more or less the same power they did the first year but I have observed a few differences in their shape and color. My panels are 2 12V 100W which mostly output 120W in total when exposed to sun; 140W I only got in counted occasions, more than that, never.
I have put them on a wood diy frame with very basic support so the back side is naked, can breathe and cool down. The panel has slightly deformed over time; plastic exposed to heat and gravity can experience plastic deformation. Also the surface starts looking whitish and less transparent. As said, with not much impact to power output for now, but perhaps yes in the coming years. Exposed plastic becomes brittle and the whiteness are microcracks which in low amount just should disperse the light but in big amount perhaps block it.

I found a chinese brand selling 400W flexible panels for 300 euros in Europe, If it was relevant to you. I think it was sunpower.