Author Topic: got free solar panels with broken glass...  (Read 10458 times)

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birdhouse

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got free solar panels with broken glass...
« on: May 25, 2011, 05:24:17 PM »
hey-
i was given two evergreen 195w panels with broken glass for free today.  these are for 12v nom. and are the older ones before they moved the production to china. 

the tempered glass is broken into a zillion pieces, but still very well attached to the eva/cells.  they also have a quite significant bulge outward.  not sure why this happened. 

it was totally overcast today, but i put a meter on each one and got 21ish Voc and 3amps shorted on each panel.  so they definitely work to a degree. 

i want to try to "repair" these so they will have a long life at my off grid cabin.  i'm not worried about a slight or even moderate decrease in output. 

what do you folks think is the best way to fix/beef up/solidify/weatherproof/make best???  i'm open for any suggestions! 

thanks
adam

richhagen

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Re: got free solar panels with broken glass...
« Reply #1 on: May 25, 2011, 06:33:09 PM »
I have about four panels in similar condition.  My plans are to put a layer of fiberglass cloth and some resin in the back of the panel, possibly with a board or two as well to give it a more rigid support to prevent the cells from cracking more than may already be the case from flexing of the laminates.   After that is done i would then put a coat of clear uv resistant epoxy resin on the front.  I don't think it is practical to try and pick out all the small glass pieces which are bonded to the eva beneath them, so encapsulation is the next best choice.  Unfortunately I have not done this yet to report to you the results.  As of now they are sitting in the basement of a building I own waiting patiently for me to get around to it.  I seem to have too many such projects in that status lately.  Rich
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birdhouse

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Re: got free solar panels with broken glass...
« Reply #2 on: May 25, 2011, 07:28:04 PM »
rich-
thanks for the info.  i fully agree that trying to remove the broken glass would be a lost cause.  my panels don't appear to have any broken cells, but not sure yet.  i'm wondering if water intrusion is even an issue, as i'm guessing the EVA is still in good shape.  this makes me wonder if putting a sheet of acrylic or polycarbonate, without even trying to water proof the added plastic on top may be a good thing.  impregnating the broken glass with a UV resistant epoxy may be worth while.  i'm guessing it may make them last ten years???  maybe a quality regular epoxy like west systems, then a uv resist top coating of some sort which could be re-applied as needed.   

i want to use these, and understand they won't produce, or last as long as "perfect" panels, but i'm totally willing to try, and see how they do.  they were FREE afterall... 

adam

SteveCH

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Re: got free solar panels with broken glass...
« Reply #3 on: May 26, 2011, 09:00:28 AM »
I bought some panels a month or so ago, and one of them arrived as you describe, bulged outward and shattered glass. I believe it is due to weight put onto the box during shipping.

dave ames

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Re: got free solar panels with broken glass...
« Reply #4 on: May 26, 2011, 09:59:56 AM »

hey adam,

could maybe try and vacuum laminate another full sheet of glass and EVA right over the top of the module(s)?

a large cardboard box, an electric space heater, a HVAC pump and a contractors garbage bag...

our forum member oztules did a great series on home brew solar panels that may be of interest.
http://fieldlines.com/board/index.php/topic,145005.0.html


cheers, dave

coldspot

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Re: got free solar panels with broken glass...
« Reply #5 on: May 26, 2011, 10:12:28 AM »
I have a friend that paints cars and has a panel like this,
I've been telling him to vacuum and or blow with air all the
loose glass off and spray the clean panel with "clear coat"
to seal it.
 He hasn't done anything yet but
My
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bamfords54

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Re: got free solar panels with broken glass...
« Reply #6 on: May 26, 2011, 02:08:41 PM »
I currently have 4 sunpower 230 panels in the same condition on my roof.
I didn't seal them at all,just mounted them as is.So far they have not
degraded noticably and they were out all winter in ice and snow.My feeling
is the cells are still sealed with the adhesive used to glue the glass on in the first place.
Only time will tell but in the meantime i'm getting quite a lot of power from the
two hundred dollars I have in them .By the way,they are all putting out
at least 170 watts each

birdhouse

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Re: got free solar panels with broken glass...
« Reply #7 on: May 26, 2011, 06:25:13 PM »
dave-
although i think the laminating with eva and tempered glass would be a stellar way to fix these panels up, i don't own a vac pump, and am trying to keep this on the cheap.  i think by the time i paid for temp glass, bought a pump and eva, i'd be getting close to buying new panels.  wish i had some of this just laying around, but don't. 

bam-  it's reassuring that with doing nothing your panels are performing fairly well!  how long have your broken panels been up?   

at this point, i'm thinking a heavy coat of west systems epoxy, or multiple coats seeing as i've got a half gallon or so sitting around.  then put a few coats of clear coat or varnish over that.  i thought about a layer of fiberglass, but i think that will just get too involved.  i wanna get this done cheap, and quick, and get these babies producing some juice!

adam

bamfords54

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Re: got free solar panels with broken glass...
« Reply #8 on: May 26, 2011, 07:30:42 PM »
I installed the panels in october of last year.The sunpower panels are in parallel with 4 sharp 175 panels
and are outproducing them.Like I said,only time will tell.

TrackerJack

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Re: got free solar panels with broken glass...
« Reply #9 on: May 26, 2011, 10:12:57 PM »
 Just clean glass as best you can. Make some type of form around panel and pour.

http://www.shopmaninc.com/kk121.html
« Last Edit: May 26, 2011, 10:17:22 PM by TrackerJack »

Rover

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Re: got free solar panels with broken glass...
« Reply #10 on: May 27, 2011, 04:36:27 AM »
hi birdhouse,

in regards to

"at this point, i'm thinking a heavy coat of west systems epoxy, or "

I'd forego the West, it does not cure clear and you will have an opaque layer. You would also need to roughen the surface to get a decent mechanical bond as West does not have great adhesive properties without additives such as colloidal silica, which make it even more opaque.

You can get clear casting resin, polyester, available at craft stores but I have no idea what that would do  to the EVA.

Rover
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Bruce S

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Re: got free solar panels with broken glass...
« Reply #11 on: May 27, 2011, 08:34:43 AM »
birdhouse;
 Another route would be to get some of the Conformal coating Rich Hagen used in the past for his 3watt LED 12Vdc lights, that stuff cures clear in spray on and looks to be clear when dry, and sticky has all get out til dry.
I have some of the 3M stuff and while its a bit on the $ side; it would lock any tiny bits not yet falling off to the panels.
I'll look up the 3M spray on stuff and let you know if you'd like.
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birdhouse

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Re: got free solar panels with broken glass...
« Reply #12 on: May 27, 2011, 06:00:15 PM »
bruce-
i'm not familiar with the stuff rich used.  sounds interesting.  i'm trying to keep this as cheap as possible, so i can buy a few more "new" panels soon, or was it more batteries i was saving for...  can't seem to remember.   ???

i still think i'm gonna go with the west systems, because it is paid for, and it's a very quality product.  i think with all the sharp edges of the glass bits, the epoxy would grab extremely well.  been thinking about putting the panels on some sort of a vibrating table to force the air out and let the epoxy seep into all the cracks.  i know west isn't clear, but at a total thickness of way less than 1/16" it's pretty darn clear.  obviously, i'd top coat it with something UV resistant for the final coats. 

my largest worry is water getting between the cracked glass, then freezing.  it'd probably be fine with nothing for a few cycles, but i'm shooting for 7-10 years out of these panels.  i'm guessing i'll be lucky if i get that!

adam

Rover

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Re: got free solar panels with broken glass...
« Reply #13 on: May 27, 2011, 07:52:41 PM »
birdhouse,

You may have an abundance of West , as I do (or other resins) ... since I use it all the time in boat repair work , fiberglass parts etc. Having an abundance of somthing does not make it the best tool for the job. Epoxy resin has a moderate to low UV resistance without additives (I have no data on use over soalr panels). IMHO,  It shouldn't be used  as a clear coat in its native form.  One of the reasons gel coats are used to to cover expoxy glass lay ups (amongst others).

It's great stuff, It just wasn't meant for this. West  (or any other epoxy resin) isn't cheap , save it , use it on something that matches it, glass layups, vaccumm bagging,  filletting etc.

Not trying to burst your bubble on the idea,  just seek a different material. I don't have a suggestiion on another one, I just know that epoxy resin .. isn't the one for a long term solution in this case.

Rover
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TrackerJack

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Re: got free solar panels with broken glass...
« Reply #14 on: May 27, 2011, 10:30:00 PM »
Bird, Using vibration to get the bubbles out of what ever finish you go with was my worry when pouring a stator. What I would do is to buy a cheap electric sander and screw it down to the sheet of plywood that I would use to pour on. Vibrator wouldn't last long but it did the job intended.
Since my first suggestion did not impress and after thinking what I would do, you should use a good high build catalyzed automotive ureathane and brush it on vigorously to get well into cracks.
Add just enough to where it flows out. Good UV, super clear, and the finish can be repaired with a little 1200 sandpaper and rubbing compond.
I myself would take a fine nap roller and stipple the finish to defuse the light. Kind of like Sharp dose with their panels... Keep the change.

birdhouse

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Re: got free solar panels with broken glass...
« Reply #15 on: May 28, 2011, 11:35:38 AM »
rover-
i'm surprised you are so against using west.  i used to work in a boatyard where we used the daylights out of that stuff.  with proper top coats of a UV type finish, i would think it would do beautifully! 

i'm gonna drop into the nearby auto shop, and see how much their clear coat is.  i would think 3-4 coats of that would do pretty well.  it last for a min. of ten years on a vehicle.  multiple thin coats applied before the previous coat fully hardens would seem to make a pretty solid build-up of finish. 

another idea i had was to get sheets of plexi that are 6-8" larger than the panels.  heat up a line 2-3" from the top of the sheet, and bend it over.  place these above the panels, with the bend wrapping the top corner of the panels, but none of it touching the panels.  leave maybe a 1" air gap.  this would seem to keep the panels dry, and protect them while leaving the panels untouched.  problem is, i don't think plexi sheets that large are very cost efective...  and they might droop if only supported on the edges. 

tracker-
"keep the change"
i didn't mean to offend you by not replying to your previous post.  the bar top resin didn't seem like the best stuff, as it is primarily used on indoor surfaces.  i like the bolting down of the cheap sander idea.  i'll bet that would get any coating deep down into the cracks. 

i once used a junker lawnmower with a purposefully very off balanced blade to vibrate concrete down a site built chute with a minimal slope to get the mud to a hard to reach pour. 

adam

 

dave ames

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Re: got free solar panels with broken glass...
« Reply #16 on: May 28, 2011, 12:15:06 PM »

 "a junker lawnmower with a purposefully very off balanced blade to vibrate concrete down a site built chute"

If there is ever a need to mass produce those off balance lawnmower vibrators my lady friends backyard is the perfect factory.  :'( LOL

dave

birdhouse

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Re: got free solar panels with broken glass...
« Reply #17 on: May 28, 2011, 12:57:36 PM »
well, the dude at NAPA hooked it up!!!!  got a gallon of clear coat, the medium hardener, mixing tubs, and the cleaner for $75.00 out the door.  the tag on the gallon of clear coat alone was 76.49...

well, time to strap on the respirator, and give this a whirl...  hoping i can bang out 3-4 coats this afternoon!

adam

birdhouse

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Re: got free solar panels with broken glass...
« Reply #18 on: May 28, 2011, 03:43:05 PM »
i've gotten two coats on.  using a roller, for consistent coverage, then back-brushing to get rid of the bubbles.  i have one of those fein (brand) oscillating cutters.  it's pretty much like a cast saw like they use in hospitals.  i jarred a burnt out cutting blade into the aluminum frame in a few spots.  the very high frequency of the saw made the clear coat soak in even better.  ten minutes after the first coat went on, and after the fein cutter action, a bunch of new bubbles came out.  i took this as a good sign, meaning the auto clear coat was seeping in between the glass particles.  so, i back brushed again to "pop" the bubbles. 

then the second coat did almost the same thing.  though i didn't use the saw on this coat.  it seems the clear coat is making its way all the way down to the EVA.  though the EVA doesn't seem disrupted by the clear coat. 

from even 6 foot away, the glass doesn't appear to be cracked anymore.  the white color of the dry cracked glass is now impregnated with the clear coat. 

all this bubble action, and irregularity of the finish makes me think i should lightly sand before i put on the third coat.  so i'm waiting for it to harden a little more before i sand, and coat again.  at this point, some of the nastier cracks are still visible in the finish, but the more uniform, and standard cracks are fully glazed over by the finish at this point. 

i've got a whole gallon of this stuff, so i think i'n just going to run it dry.  i've got five hours until i need to meet some friends out, so here goes something   :o

adam

Simen

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Re: got free solar panels with broken glass...
« Reply #19 on: May 28, 2011, 03:46:45 PM »
I have 2 panels with near 'pulverized' glass, and they have been outside in all kinds of weather for over 4 years; from 30C+ summer, to -15C winter and snow, and everything between. None of the cells have any sign of deterioration at all, and they give the same amp now as for 4 years ago, which are 25%-50% of stated power, due to the fractioned glass... I guess the silicone or whatever are protecting the cells. :)

But what would be interesting, would be a way to 'unfracture' the glass, so that the sunrays wouldn't get dispersed so much before they reach the cells.
I've seen some commercials for windscreen repairs where they fix rock cracks with a kind of a suction/pressure thingy placed over the crack, and some goo are injected, magically removing the crack... Anyone know what that is?!

Adam:
Interesting results! :)
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ghurd

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Re: got free solar panels with broken glass...
« Reply #20 on: May 29, 2011, 01:09:49 AM »
Anyone know what that is?!

I do not know what it is, but I know a little bit about it.  Just used it last week ("Fix-A-Windshield").

Maybe one of the chemists can narrow it down:
It is just a tiny bit thicker than water.
The instructions call it 'resin'.
UV activated.
Contains methacrylates.

I did not have a lot of faith in the kit.  The bullseye in my windshield was nearly 1.5" diameter.  Not a regular bullseye, this almost looked like someone taped a white paper disk to windshield.  Naturally, straight in from of my eyes.

The apparatus (about 3/8" dia) would not cover the whole bullseye, though the stuff worked its way to the edges (after repeating step 4-6, like the instructions said to do if the cracks did not fill).
Looked very very good!  So I filled another much smaller smaller bullseye too (did not work very well because it must have dirt in it after ~10 years).
Moved it into direct sunlight for >90 minutes (instructions say fully cured in 5-10 minutes).
Amazing.  Could hardly tell where the bullseye was.  Except for a very slight distortion, and my fingerprint (my curiousity ruins many projects).
Down the road maybe 1/4 mile, and the center of the bullseye starts to grow back.  (damn)  After 2 miles on semi-bad road, it gets bigger.  It is still exponentially better than it was.
I think a second application will fix most of the regrown area, except it has to be done when the crack is DRY and it will not stop raining.  Could be my bullseye still had moisture in it.

Also seeps into cracks semi-reasonably well.  Again, the crack in my windshield is ~10 years old and certainly dirty, but it did help.

I think it would work pretty well for a solar panel.  Except I paid $11 for the kit, which contained only 0.035oz/1g of resin.
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birdhouse

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Re: got free solar panels with broken glass...
« Reply #21 on: May 29, 2011, 10:33:24 AM »
here's what the panels looked like before i'd done anything to them, other than a thorough vac job. 



after two coats, i was able to run the palm sander on them without hitting any glass.  this was needed to get rid of some of the marks from where the air bubbles were coming out.  i was pouring the coats on right out of the bucket, then rolling it in, then brushing. 
here's a pic right after sanding-



here's a pic after the third and final coat.  i think they look better, and hopefully now have a second skin to help protect them. 



it's supposed to be sunny this afternoon, so i'm gonna try and see what they can do!

they are 195w evergreens with a Vmp of 18ish, and their final home will be with a 24v nom. bank.  so i'll have a Vmp of 36ish.  this extra voltage may help them with their imperfectness. 

adam

Harold in CR

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Re: got free solar panels with broken glass...
« Reply #22 on: May 29, 2011, 03:16:45 PM »

 That looks pretty good to me. How sturdy is the panel, now ?? Did you or are you planning to beef up from the back side ??

birdhouse

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Re: got free solar panels with broken glass...
« Reply #23 on: May 29, 2011, 03:32:28 PM »
harold-
i think i'm gonna use them as is.  it'd be better to beef up the back.  if anything, while i'm mounting them, i may run a 2x4 or two down the backsides.  thinking i'll make the mount tilt-able, to keep them near vertical during the winter months to keep the snow build-up to a minimum.  i'm not real keen on additional solid backing due to the potential for making it difficult for heat to escape from the back of the panels.

i've got one of 'em out in the yard right now with batteries, ammeter, and volt meter hooked up.  weatherman said the sun would come out an hour and a half ago, but still socked in with overcast.   :-\ 

hopefully, i'll get some decent results if the freaking sun will ever burn this crap off!

adam

birdhouse

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Re: got free solar panels with broken glass...
« Reply #24 on: August 17, 2011, 07:28:31 PM »
sorry folks-
i thought i finished this thread off with results, but apparently i didn't.  i don't remember the volts or amps, but i do remember multiplying them, and getting between 80-90watts out of one 195w repaired panel. 

not bad for free!

adam