Broken solar panel - can it be resurrected?

[birdhouse]

yes, i poured the finish, then brushed and rolled.  i also used a two part automotive clear coat, so dry times were'n't a big deal.  even 1/16" thick coat, would dry/harden in about 15 minutes. 

i wanted the coats to be thick in order to give the glass some additional strength.  after i poured each coat, i would use a fein saw to vibe the panel to allow the finish to settle down into the cracks between the glass. 

clear coat, is very clear, and hardens quick, so i wasn't worried about the coats being thick.  plus the panels were free, so i gave it a whirl. 

i was able to give enough thick coats that i could run my bare hand across the front of the panel, and no longer feel any portions of broken glass.  i called it done at that point. 

adam

[Bruce S]

Adam;
Where did you find the clear coat? I'd like to give that a try on a panel at a neighbor's home.
Murphy paid him a visit while he went in to get his wife to show off his new panel ( That was NOT secured down)  .
Only took 1 min for wind to blow it off his shed  .
OOPS!
The cost too if you have it.
Thanks
Bruce S

[Steadfast]

Yeaterday evening I checked the varnish on the panel.
There is ZERO fog in it and it was just a little bit tackey to the touch.

the varnish is crystal clear transparent, but it is also just slightly tan in color.
and I am thinking adding more coats will make the "Tan" darker...
and make it harder for the panel to see the sun.

So,
Im not sure if I should bother sanding it with my 320grit foam sanding block
and adding a second coat... I'll post photos before I proceed...

but what do you guys think?

[Frank S]

SF do your self a favor walk away don't look at it don't touch it don't even think about it for a week unless it is to put it in full sun to cure and even then it were me I'd cover it with a clear acrylic or a piece of glass to protect it from the night dew.
 I once knew a guy who restored old boats he would brush coat the teak pieces that could not be sprayed then not touch them for 2 weeks then he would sand with 1000 grit then 2000 and finish off with 3600 grit before polishing sometimes to get it just perfect he would ruff sand with 400 then add a second coat and wait another 2 weeks.  But he could wet sand you cannot  because you don't know the quality of the seal.

[Steadfast]

Right.... walking away...
Not looking at it....
Not touching it...
not even thinking about it for a week...
I hear and obey! 

I will also take a picture of it.
but I promise I wont think about it when I do...

On Saturday, when I am home all day, I might put it in full sun to cure...

[Steadfast]

I appreciate your advice with this varnish thing.

You know,
I have completed tons of wood projects and I have NEVER used varnish until now.
I mostly use Danish oils with baked in carnuba wax...
I have always considered varnish to be "The shoddy wood worker's finish."

To me Varnish is dishonest because it is so thick that hides the flaws in the wood, making it's sculptor look better than he actually is.

My lack of experience with this heritical varnish stuff is why I wanted to avoid varnish all together.
That is until the glass price melted my brain!

Just for laughs and giggles
Here is just one photo of some of my wood work:

[birdhouse]

bruce-
i got a gallon+ kit from napa.  as soon as i told the guy i was using it to repair a few broken solar panels, he got really stoked on the project, and gave me a pretty good deal!  i ended up getting the gallon of resin and quart?? of hardener, and the same brand of cleaner (acetone type stuff) for $75 total.  though i think you can get quart kits for cheaper. 

adam

[Bruce S]

Thanks;
There's a NAPA about 7 miles from the house, I'll drop by and see.
at 103F out I'm not doing any of this until it drops below 99

[Steadfast]

Here are the drying photos

[DamonHD]

Are you really expecting us to watch varnish dry?  B^>

Hey, what you need now is a web-cam!

Rgds

Damon

[Steadfast]

Well... like me... as slow as it is drying...
That is exactly what you just did by seeing my pictures..   

The reason I posted those photo, besides annoying you, 
was to find out if my one thick coat of varnish LOOKS good enough...
Or should I add another... "Next week"

perhaps, a thin coat of varnish, with a layer of thin clear plastic stuck on top of it???

[DamonHD]

I'd be very wary of putting anything other than low-iron glass in front of it, since it may absorb the wavelengths that the cells would absorb, and/or may discolour with UV over time blocking even more light.

Rgds

Damon

[Bruce S]

SF, since this is a free panel  sorta, after this dries, check it's output. Make sure its doing something.
Then if you can run your hand over the surface without getting cut or nicked, then leave it to cure a bit longer then stand it out in the sun and let'er work.
IF you feel sharp point then I'd personally put on coats until it's safe for kiddies to touch.
I have 6 grandchildren so that's what drives my decisions, since broken stuff I tend to leave down where I can work on or use for testing.

Question? show the solidarity of it since its begun to dry? no flexing? or did you shore up the back too?

 

[Steadfast]

Bruce,
thanks for the advise,
I as thinking the same thing...

I plan to glue some free pallet wood boards, i was given,  to the back.

[Steadfast]

I tested my replacement 100watt in full sun it only cranked out around 60watts
is that right? 




I guess both the broken/repaired one and the replacement should do around 100watts when combined... 

[Bruce S]

leave it out in the sun. From what I remember , I had to leave mine out and let them break in so-to-speak.
How's the repaired one doing? has it dried yet?
the pallets I use are white oak cast-offs and they're great for outdoor stuff. I put a couple coats of CWF on them and they hold up very nice.
It's good to see your battery bank getting up over the low level of 12.44!!

[Steadfast]

huh,    I did not know this....
how long does it normally take to "break them in"?

it looks dry, feels dry... but I am suppose to
"walk away, don't look at it, don't touch it, don't even think about it for a week"

I think that was 4 days ago....   

[Mary B]

Your battery isn't very low so the panel is only putting out what it needs to charge.

[Steadfast]

Your battery isn't very low so the panel is only putting out what it needs to charge.

How can a solar panel know that...?
I thought it just "output" whatever it could...
did you mean the solar controller is only putting out what the battery needs...?

[Rob Beckers]

Solar panels do not 'break in'. In fact, it's the opposite... Used to be that poly-silicon cells had a quick initial degradation once they were exposed to the sun, followed by a steady decline in line with mono-silicon. Nowadays both types behave the same; they loose around 0.5% a year or thereabouts, in power output.

Your panel's rated power is determined under very specific, and very artificial, conditions: The cells in the panel are at 25 degrees Centigrade, it is flashed with a light source with a specific spectrum (much like the sun's spectrum) at an intensity of 1000 Watt/m^2, and the panel is run at its maximum-power-point (MPP) voltage.

None of those conditions are the same when you test your panel propped against a box in the grass, connected to your battery. The sun may be more or less than 1000 Watt/m^2 (usually less, we only see that kind of radiation at high altitude or on crisp clear winter days), your panel will almost certainly be more than 25C and the warmer it is the less it produces (0.5% less for each degree over 25C), and it is being run at your battery's voltage which is very likely quite a bit below the MPP voltage for that panel.

The current doesn't change much with temperature or voltage (to a point), it's mostly determined by radiation.  It's showing 4.49A (at 12.75V) for your panel? By comparing that to your panel's rated current you'll get an idea of how close the radiation is to 1000 W/m^2. As your battery gets charged, the voltage will rise, and so will the output power of the panel (the current will stay just about the same, unless the panel gets really warm, or you get to a fully charged battery). Power is simply Current x Voltage. For a 12V battery, these panels use 36 cells, which means their best voltage at 25C, their maximum-power-point, is around 18 Volt, and this drops by about 0.5% for every degree Centigrade above 25C.

Looks like your panel is working fine...

Hope this helps!

-RoB-

[Bruce S]

SF;
Remember the battery will only take just so much from the panels. The higher it's charge gets to lower input from the panel they will need. So as the higher the voltage gets on the battery the harder the panel will have to work to add anymore, otherwise the battery could get overcharged causing it to boil .
Bruce S

[Rob Beckers]

SF;
Remember the battery will only take just so much from the panels. The higher it's charge gets to lower input from the panel they will need. So as the higher the voltage gets on the battery the harder the panel will have to work to add anymore, otherwise the battery could get overcharged causing it to boil .
Bruce S

Bruce, that's why people use charge controllers. If you leave it up to the solar panels they'll quite happily boil a battery dry, if there is no charge control...

-RoB-

[Steadfast]

Thats...OK...
Zero Boilage for MY SYSTEM...
I am like TOTALLY prepared... 


because I am also flying my wind turbine on the same system
I just happen to have both a solar charge controller AND a load dump...

Yea Me...   

[Steadfast]

Once I add the wood to the back of the repaired solar panel...
The Next thing to do is to install both (the repaired and the replaced) panels on my shed's roof...

Soooo... any hints on how to build some simple roof mounting clips
(Remember, I have my own forge and anvil, and I am not affraid to use them)
Hint hint: with out your intervention here, I WILL simply be forced to devise my own...

Also, how I should go about running my line from the pannels through my sheds roof so it does not leak? (I was thinking about busting out a drill and also using some of that putty tape I have for camper roof repair.)

[Bruce S]

RoB-
It was ONLY an example to help SF along.
A solar controller is not always necessary, I use dump load controllers (Ghurd gold standard) on smaller systems, along with a full-wave bridge rectifier and a small peltier to keep the "rec" cool.

SF, does your shed have eves? If so then you could do like we did in the Philippines, you can create a drip line by allowing the wire coming from the panel to be a bit lower than your eves, feed to wire up into the eves and secure them there.
Even in the pouring rain, there was NO incoming water even on the thatched roofs.
Mounting them to your roof is entirely up to you. I welded angle iron together then used clips to hold panels in place for one of my neighbors units.
Just a thought.
Bruce S

[Rob Beckers]

Steadfast, in general I would advise not to attach the panels directly to wood. People do it, most of 'm get away with it, but if that wood warps, twists, shinks, or otherwise changes dimension, it will put a heck of a lot of force on those panels. Running some metal behind them (that can be fastened to wood), such as a simple aluminum profile, and attaching the panels to that, would be my preferred method.

Bruce, a dump load controller is a charge controller in another form, and they work great! Instead of being in series (which works for solar, but decidedly not for wind) it's in parallel, and then the name changes to a 'diversion controller'. All you need is one controller in the system that can handle the excess power; when the batteries are full a diversion controller will divert the excess to a dump load. So, if you already have a diversion controller for wind, by all means, hook the PV modules directly to the batteries. The diversion controller will take care of keeping the batteries from overcharging, for both wind and solar.

-RoB-

[Bruce S]

RoB
please explain why it would not work for wind? I can see where a solar controller would be bad for wind .

I've quiet a few different designs and different chemistry battery types that needs different voltage levels beyond the normal purchasable controllers.
Plus I've setup more than few , so with no charge controllers at all.

I do agree though, wood could turn into a bad idea.

[Rob Beckers]

Bruce, solar panels are current sources; they are limited by how much current they can supply and that makes it easy for an electronic switch (like a MOSFET, FET, or IBGT) to rapidly switch them on and off, and by varying the time that it's 'on' vs. 'off' it controls how much current flows effectively into the batteries. When the batteries are full it can switch the panels completely off, no bad things happen to panels or controller. That's how 99% of regular PV charge controllers work (they're called 'pulse-width-modulation' or PWM controllers for that reason).

If instead of solar panels you were to connect a wind turbine to the input of such a controller, in series between turbine and batteries, very bad things happen very quickly: Rapidly switching the turbine on and off as it would do for solar will cause large voltage spikes, killing the switching semiconductors in short order. If the controller were to survive, and switch off the current to the batteries completely when they are full, most small wind turbines will run away and quite possibly self-destruct because they have to have a load on them at all times. On top of that, wind turbines with a partial or no load spin too fast, and generate voltages that are too high, which will also kill the controller.

That, in a nutshell, is why solar controllers do not work well for wind. Now, keep in mind that the popular ones such as the TriStar etc. can also be used in diversion controller mode, where they are no longer in series with the source, and that will work fine for wind turbines (but you have to supply a dump load, something that's not needed when used in series mode).

Hope this helps!

-RoB-

[Steadfast]

The resurrected solar panel and the wood that's gonna reinforce its back.


Wood installed...


Here is a photo of many things.
Yes we used an old bed frame.
Also, you can see the use of my black tar putty tape
both under the foot and to water proof the screw as it goes through the roof.




I took this from on top of the shed roof.
You can Clearly see the diference between the resurrected panel and the replacement panel.




And the Bottom line...
This is the combined output of both panels in full sun!

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[Steadfast]

on sunday:

The two solar panels were pulling in a happy and alarming 135 watts, the batteries loaded upto 14.25 volts and my load dump switch came on and the dump sytem was instantly painful hot, but not burning hot to the touch, (that yellow light was a-flicker-in) all day LONG...  ghurd's load control switch works GREAT....   You guys should all buy one or two from him! 
(I the wind turbine only cut in breifly ... like 2 seconds...)

I want to use that electricity for more than running a dump...

I still have that 35 feet of that 14awg wire... It is long enough to reach my Chicken coop too...
I know my chickens would LOVE to have a few fans running on them in the summer and perhaps some small heaters in the winter. I would also like to be able to light up the chicken coop or the coop's side shed at night from time to time.

So here are my NEW wireing idea plans...
The top drawing is using the inverter I already own inside my sealed shed with a outlet switch in the shed.
The bottom drawing shows a new 2nd inverter inside the shed as which also is the on/off switch. The difference is that the top one requires that I unlock my shed to switch on the inverter everytime I want to run the coop. The bottom all I gotta do is switch the power on on in the scoop shed.

and now, my questions... I can not decide which one to do...

The coop side shed has only chicken wire as one of it's walls and no door, would that pose a moisture problem for a new 1600 watt cobra inverter if I added one in the coop shed? (why the 1600 watt cobra inverter: I might as well be able to run power tools at the coop as well)  The PVC houses the wire and is buried. if i use the top plans can i simply leave the inverter on forever inside the locked power shed?



Site informitive photos:

Two "young bird" and/or "Bad bird" holding pens inside the coop shed.
(new product of my wife's recent honey do list)
you can see the chicken wire wall that seperates the side shed from the chicken run.


The out side of the finished side shed:



For fun, here is a link to a video tour of my coop before the new chicken holding pens where added into the coop's side shed...
http://www.fieldlines.com/index.php/topic,146857.0.html
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[Steadfast]

leave it out in the sun. From what I remember , I had to leave mine out and let them break in so-to-speak.
How's the repaired one doing? has it dried yet?
the pallets I use are white oak cast-offs and they're great for outdoor stuff. I put a couple coats of CWF on them and they hold up very nice.
It's good to see your battery bank getting up over the low level of 12.44!!

BTW: you where right about that "breaking in" thing...
As you may remember: My two panels started out making only 95 watts on a clear day...
now they are making 140-150 watts on a clear day regularly!

Thats some break in!   

[Steadfast]

by the way:
here is the video tour of the solar powered electrical work now finished in the coop.

[Bruce S]

 
Can you tell how the broken one is doing on it's own? It'd be nice to see what output it has.
Now that is has had time to cure and probably settle down to what it'll be putting out for the years to come.
Cheers
Bruce