Broken glass solar panel (mistake)?

Chris Evans

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Joined
Jul 4, 2017
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8
Hi all,

I may have made a slightly knee jerk/silly decision today. I've bought 16 320Wsolar panels from a gumtree seller, all with broken glass. 25 a pop. I actually haggled and got them for 350, but that's besides the point. Have I made a mistake????

My rationale is, I have no solar panels at the moment to speak of, and I've got theoretical 5.1kW of panels for the price of 1 new perfect one? I know i'll more than likely get no where near 5kW but I thought it was worth a bash at fixing them up.Resin orvarnish maybe?? Has anyone got any suggestions?

Worth noting I picked the panels with good 38V on the meter when in the sunshine and left the others.

Cheers,

Chris
 
I wouldn't call it a mistake, more like a great find! :)

The glass is relatively easy to repair. You can't really replace the glass as the cells are epoxy'd to the glass. However, you could add in a clear filler that will connect all the shards back together and minimize the chance of one falling out.
Now, if you "can" get the glass to come out, then you might be able to replace the glass. If you can, then I'd suggest looking around for sliding glass doors, large windows, etc that might be being sold at garage sales, craigslist (or whatever your counties version of it is), recycle centers, reclaim centers (we have one called the Repurpose Project; ppl generally just give them left over scrap, or removals from remodels and they sell for dirt cheap; these are actually a not for profit in our local city)

You can at least start your projects with those. And now, every other panel you buy at full price has been slashed lower due to these being so cheap. So the overall costs will be far lower.
And smart move for hand picking the voltages.
 
I can't see why that would be a mistake either. Seems more like a good deal to me. The glass can be fixed, Youtube has an extensive amount of HowTo videos abot that, I'm sure!
 
Nice little score.
Can I assume that by broken, you mean the glass is cracked but none of the glass is missing?
If that is the case and you are only concerned about water ingress, then perhaps you could use some self-adhesive clear film?
Kinda like the stuff school kids wrap their books in.
Pretty sure you can get this stuff in various widths and from memory 3M/Avery/Arlon make UV stable vinyl films.
The film may lose you a few watts, but for the price... meh

Just a thought.

EDIT: Or clear window film... here's a random youtube vid showing application:
 
This guy made a fairly clear video about the process.



Exterior varnish works well and isn't too expensive. Best applied with a gloss roller (not a fluffy roller) but will take over a week to dry fully. I went for just one coat, but may try 2 thinner coats next time. I've not managed to find an exterior varnish which is completely clear, they seem to have a yellowy tint to the finish.

Cleaning them thoroughly before applying the varnish is a must. The cleaner the better, then hoover off any loose bits, then varnish. Doing this outside may attract a lot of bugs which could get stuck into the varnish.

While the initial cost of the panels is low, once you factor in the cost of varnish and the time to apply it, then factor in the life-span of the panels (I'm guessing 5 years or so compared to 25+ for unbroken ones) the saving is still there, but less significant.

I went for cracked panels because of cost, my entire solar budget is less than the cost of just new panels.

Try it and see. at that price it's a gamble worth taking!


I used this varnish by the way.

http://www.wood-finishes-direct.com/product/dulux-trade-clear-gloss-yacht-varnish
 
To expensive if you ask me... but all have different prices on their free time :)
 
Besides water getting into the panels, another concern is structure strength (how big are the cracks?) and the actual solar cells are very weak and break easy like super thin glass. Some sort of epoxy might be ideal for the strength. If you live in an area with snowy winters this is a more major concern, if not rain water probably isn't such a big deal. Water in the crack is if it freezes though.
 
Did you ever get any of these panels setup? I've just finished connecting up 2 300W panels with cracked glass. I'm in essex in the UK and the sun has not really been out this week at all. I have been getting at most 1.5A from the panels in series at the charge controller. I used an exterior clear varnish to seal the cracks. Seemed to work pretty well.
 
I'm no expert on solar, but I'd suggest testing each panel separately and make sure they put out close to spec (within 80% should be a fair target). Wired in series will limit you to the panel with the lowest amp output if I'm thinking right Parallel would probably be better since I think the voltage would either average out, or the lowest voltage would be your output, but long distances with low voltage isn't fun or cost effective.
 
ChrisEvans said:
Hi all,

I may have made a slightly knee jerk/silly decision today. I've bought 16 320Wsolar panels from a gumtree seller, all with broken glass. 25 a pop. I actually haggled and got them for 350, but that's besides the point. Have I made a mistake????

My rationale is, I have no solar panels at the moment to speak of, and I've got theoretical 5.1kW of panels for the price of 1 new perfect one? I know i'll more than likely get no where near 5kW but I thought it was worth a bash at fixing them up.Resin orvarnish maybe?? Has anyone got any suggestions?

Worth noting I picked the panels with good 38V on the meter when in the sunshine and left the others.

Cheers,

Chris

Nice find - just a couple of years ago, while in Colorado, I had hail damage which cracked a dozen of my older panels. I just covered the broken glass with new pieces and siliconed them in place along the edges (like a fish tank)...... Personally, I like working with glass, but you must be careful - and it is time consuming.

After testing the panels and verifying the integrity of the unit, I'd just put new glass right on top of the old glass (cut to the correct size) and silicone the edges - although the broken glass cracks would show through visually, this would strengthen and make it water tight again. Yeah, i know, it won't have be 100% efficiency, but it should certainly good for backup panels if you have the space. It depends on the number of cracks, etc.

I have found that varnish and other items can yellow over time. I am not sure about this particular panel, but to remove the old glass and replace would take a fair bit of time, and time is expensive. Plus, you may actually damage the cells during glass removal process.
 
Al said:
This guy made a fairly clear video about the process.



Exterior varnish works well and isn't too expensive. Best applied with a gloss roller (not a fluffy roller) but will take over a week to dry fully. I went for just one coat, but may try 2 thinner coats next time. I've not managed to find an exterior varnish which is completely clear, they seem to have a yellowy tint to the finish.

Cleaning them thoroughly before applying the varnish is a must. The cleaner the better, then hoover off any loose bits, then varnish. Doing this outside may attract a lot of bugs which could get stuck into the varnish.

While the initial cost of the panels is low, once you factor in the cost of varnish and the time to apply it, then factor in the life-span of the panels (I'm guessing 5 years or so compared to 25+ for unbroken ones) the saving is still there, but less significant.

I went for cracked panels because of cost, my entire solar budget is less than the cost of just new panels.

Try it and see. at that price it's a gamble worth taking!


I used this varnish by the way.

http://www.wood-finishes-direct.com/product/dulux-trade-clear-gloss-yacht-varnish



I repaired a 100 watt panel using the method and product in this vid. Seems to have worked ok
 
As this was posted in 2017, I'm interested to know how you got on, is it still working well after 2+ years?
 
It's a trade-off: yes initial cost should be much lower but output will be lower, life-time will be much shorter, corrosion with get in soon.
Resealing like the original so the cells are really waterproof between glass & the EVA plastic backing sheet - no cracks from the edges for water to creep in from - would be tough to achieve.
The other issue is cell micro-cracks & the problems that causes (local heating, lower output, etc).

Probably for experimenting or ultra low budget, etc - wouldn't use for a new system...
 
Hey guys, maybe you can help me as I am an absolute newbie. I want to buy a second hand solar panel for my eldest son, so he can practice installing it (he's really into it). So my question is, where do I look for (I am currently checking gumtree and ebay for 2nd hand options), and how do I transport it?
 
Also check craigslist if available to you, depending on size of the panel it might fit in a hatchback with rear seat down, or a pickup/ute laying flat with support under the entire frame of panel. Blanket under it. to learn about installing panels you could use more than a single panel 2 or more .:) then you need a charge controller and storage(Battery).
you should make a new thread for this
later floyd
 
floydR said:
Also check craigslist if available to you, depending on size of the panel it might fit in a hatchback with rear seat down, or a pickup/ute laying flat with support under the entire frame of panel. Blanket under it. to learn about installing panels you could use more than a single panel 2 or more .:) then you need a charge controller and storage(Battery).
you should make a new thread for this
later floyd
Thanks Floyd! I will look for the package deal then. I don't drive, but called a local company in Brent Crossand they said they can move it for me on a weekday. I will post a new thread once I have it delivered and hopefully Adam figures out how to put everythingtogether and make it work :cool:
 
TracySt said:
Hey guys, maybe you can help me as I am an absolute newbie. I want to buy a second hand solar panel for my eldest son, so he can practice installing it (he's really into it). So my question is, where do I look for (I am currently checking gumtree and ebay for 2nd hand options), and how do I transport it?
I've purchased all of mine on ebay - but I had to have them shipped to me. If you do this, you need to find them as close as you can - for example the shipping from CA to OR was $300 for 21 panels (1000 lbs) For 1000lbs it was $600 shipping from FL to OR - so I saved $300 or $14.29 per panel by buying them 'closer to home'.
 
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