Flexible Panels hit Prime Time?

[Xerxes]

Maybe Renogy plans to go public....

.........so when the cash payout for those warranties start it will come out of someone else's pocket.

Meanwhile they drive up market share and industry interest in their product so the share prices are sky high when the owners sell out to the public-financial investment group/bankers, or larger solar company.

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I wonder how Renogy simulated 25 yeas of wear?????

So they crank up the UV lights to X3000 to simulate 8 years of UV every day of test use.

The bend and twist it 300 times a minute to simulate 8 years of flexing every day of test use.

They rounded up 5 schools full of small children to walk and jump up and down on the panels to simulate the full 25 years of use in one test day....

But seriously I wonder what the test method was for proof of concept and proof of manufacture technique.

The UV thing is interesting as damage is slow/long term and just cranking up the power X100 does not necessarily mean damaging it 100 times faster. It takes time to break and create new molecular bonds......(turn yellow, curl up-warp, become embrittled and crack).

 

[MrNatural22]

They can send me one and I’ll give it the ole merciless Arizona sun for a couple of seasons. Bwahahaha ? ?
Even UV proof stuff dries, fades and crackles after a couple years.
In 10-20 years it would become “dust in the wind” ? ? ? ? ?

 

[DerekH]

I was seduced by the warranty. Bought 12 for installation on a lake-faring vessel in the heat intense US Southwest. Will report back after a couple of years of use... ?

... if they make it that long ?

 

[tim0shel]

I actually ordered some flex panels not Renogy's but some others that arrives this Thurs. But I'm using them for camping and easy of transport and setup. Like to have some material sewn up around some coroplast where I can fold the panels up and also have them something to hold them flat.

 

[svetz]

Dang good questions... let's see what Mr. Google has to say about some of these things....

...I wonder how Renogy simulated 25 yeas of wear????? ETFE has been around for over 40 years [ref] and it's properties are well known. Architects use it to replace glass and it's in a lot of famous places like the roof at Manchester Piccadilly station or the National Space Centre.

...I was seduced by the warranty. Looking forward to the report!!

...Even UV proof stuff dries, fades and crackles after a couple years.... It's not so much UV Proof as UV transparent, it's lighter and more transparent than glass. ETFE resins are resistant to ultraviolet light. An accelerated weathering test (comparable to 30 years’ exposure) produced almost no signs of film deterioration.[4]

If ETFE is so great, why do they have a bad reputation?
From ref1, ref2:

• Not resistant to punctures, hail was the last straw for one 23 year old roof
• Birds pecking at it are a known cause of failure (Seagulls use the ETFE Roof membranes as an ideal platform to stop and peck at shellfish)
• It's impermeable to water, any water that gets underneath stays there.
• The mechanical properties depend strongly of the material thickness (sounds like heavy lasts longer)

So, in the end all of I've learned is that in theory ETFE should be the best thing that's ever happened to solar panels, and yet practice says it ain't so. Ain't hard to google and find:

• Showing cracks (which sounds like a UV stabilization or over-bend issue)
• Delaminate
• Cheap Grade B or C sunpower solar cells. [ref]
• Overflexing breaking traces
• jbox delamination

It may well be that ETFE is a wonder material going through some growing pains. If you look at the cost of a rigid glass panel vs the cost of the cells its easy to see a lot of that cost is just in the making of the panels. So possibly at some point ETFE may entirely replace glass for panels once all the kinks are worked out.

 

[svetz]

Since Renogy replied quickly that the warranty information was indeed accurate and needed no special mounting, figured I'd push my luck and ask why the new EFTE was better than the old... here's the response:

The new models are just made more rigid, which in my experience has had less failures, and have proven more durable and have just given overall more longevity in life span.

 

[svetz]

(Click image for audio)​

 

[nosys70]

i worked for dupont lab in switzerland where they opened a unit for solar panels. They spent a lot of money to get all the equipement to build/tests panels, but they closed soon after. I think they were not able to provide a plastic that was as great as glass or the market was too small for panels using expensive plastics.
for sure they are situations (aerospace, military, adventure) where such product are interesting, because the requirements are high and lifespan or price is not an issue.
the rickshaw project could be part of it, but when i see the size of a single 100W panel, it is hard to imagine sticking five of them on the roof of a rickshaw. but it can already reduce the battery requirement a lot so it could be useful to test, even with a cheap one.

 

[svetz]

nosys70 got me wondering...hadn't thought about ETFE for space flight, it is lighter and cheaper... NASA tested two different types of ETFE as a wire spec.... I wonder if cross-linked is the secret sauce?

ETFE(Dupont TM Tefzel)	Withstands physical abuse during and after installation Good high and low temperature properties High flex life Good outgassing characteristics Fair cold flow properties	Some ETFE insulations fail flammability in a 30% oxygen environment Insulation tends to soften at high temperature Degraded by gamma radiation above 106 RADS
Crosslinked ETFE(Dupont TM Tefzel)	Higher strength than normal ETFE Resistant to cold flow and abrasion More resistant to radiation effects (to 5 x 107 RADS) Higher maximum temperature than normal ETFE Tin Coating = 150°C Max. Silver Coating = 200°C Max. Good outgassing characteristics	Some ETFE insulations fail flammability in a 30% oxygen environment Less flexible than extruded ETFE More difficult to work with than PTFE Teflon

 

[nosys70]

yes, but probably the main concern was " More difficult to work with than PTFE Teflon "
When you know how tricky it is to work with PTFE.
I have seen sample panels at the lab and discussed with the engineer, and the main goal was to provide textured surface panels, so you can walk on it.
I think the main target was boat.
To be frank, when i saw the samples, the first thought was the plastic looked really dull and milky, so i think the yield was probably greatly diminished.
a good candidate for covering silicium would be BPA (Bisphénol A ) a precursor of polycarbonate ,
it is widely used and cheap..

Industrial Polycarbonate Plastic & Epoxy Resin Uses | Facts About BPA

Learn about industrial uses for polycarbonate plastic and epoxy resins. From efficient lightbulbs, paints and coatings, to aircraft, BPA has many uses.

www.factsaboutbpa.org

I am not sure it can stand UV for long, but it could be applied in very thin layer.
PMMA is also very interesting

 

[svetz]

Don't have a recumbent sBike, but perhaps it's time to change that? Especially if the same "solar" bimini can be pulled off the kayak to run the bike. Obviously with a bimini, even with the carbon fiber rods, tops speed shouldn't be too much to avoid wind resistance. Probably dreaming, but lets call that 10 mph. Mr. Google says 20 watt hours per mile is reasonable at a 20 mph cruising speed. If it is 10 wh/mile @ 10 mph, that's 100 watts. (Some pedaling probably required ;-)

 

[gnubie]

If you've ever been on one of those things on a road you'll know just how scary it is. You can't see a thing, apart from the doors and wheels of cars / trucks / what ever next to you. Give me the height of a normal bike any day.

 

[DASH]

I think something was missed when looking at the warranty:

"The warranty does not cover failures result from incorrect handling, product modifications, installation, conversion or additions, supplements, operation, natural elements (weather), excessive or deficient energy supply, chemicals, the effect of solid bodies or deliberate damage."

Warranty does not cover natural elements (weather). So if the panels fail because of the sun/heat (which apparently does happen in hotter climates) does the warranty apply? I think not.

 

[svetz]

......The warranty does not cover ... natural elements (weather)..."

I don't have a reference, but I'm pretty sure the last time I got roof tiles it said something similar. Suspect that it means hail, lightening, wood-peckers, tornadoes, etc as opposed to normal weather.

 

[svetz]

...If you've ever been on one of those things on a road you'll know just how scary it is. You can't see a thing, apart from the doors and wheels of cars / trucks / what ever next to you....

Good to know... although a two wheeler is probably beyond my skillset now. Guess I need a middle ground or wait until after the zombie apocalypse when there are fewer cars/trucks on the road.

 

[HRTKD]

svetz, maybe something like this is more your style?

 

[svetz]

...svetz, maybe something like this is more your style?

I think that would meet Gnubie's elevation requirement. But for me at least... it would need to come with training wheels or other balance system; preferably something high tech like this gyroscope motorcycle.

 

[HRTKD]

And a helmet. Solar powered helmet with PCM cooling system?

 

[svetz]

So are these the only two dream projects for lightweight flexible solar panels? What about a fiber carbon vacuum blimp? If you had infinite time and money, what would you build with them?

 

[Supervstech]

Infinite money...

Full size this...