best way to repair solar panel

Hello out there,
I suffered some damage to a new panel when installing it. A screw driver dropped on the bottom side, puncturing right through the white back layer and the cell, right down to the glass. It did not damage the glass, but it basically shattered the cell in 1/8installing dia spot on the edge of the cell.
How will this effect the output of the pv, i guess i might loose this cell ?? or is it worse ??
what would be the best way to repair this, some have suggested silicone, but is there not a better material ??? epoxy or urethane ??
would greatly appreciate the feedback.
boardmon

Comments

  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: best way to repair solar panel

    it's not as simple as throw some silicone on it and forget it if that was to be in a series string. that pv is now different than the others and will degrade the whole bunch in the string in that case. this is now like having 2 different pvs in series. i will agree if the voltage has remained identical to the others for paralleling that pv with the others. if the voltage is reduced it would reduce all of the paralleled pvs and not just the one. yes the pv will probably still produce depending on how much you damaged it, but it is no longer the same as its brothers and sisters on the assembly line and is inferior.
  • System2
    System2 Posts: 6,290 admin
    Re: best way to repair solar panel

    Just a thought on the silicone calking. Standard silicone calking releases acid while curing. I've had it turn copper wires green and in time, eat fine ones off. RTV silicone and silicone II (by GE) however do not have this problem. One other thing, have run into silicone II that wasn't new and it wouldn't cure, just remained a gooey mess.
    Wayne
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: best way to repair solar panel

    henry,
    you aren't really educating me as i already know most of this. in parallel there should be no problem then because the same voltage exists, but under heavy load the voltage could sway like batteries do because the internal resistance being different even though not by much. i would like to hear of some of your experience on this. in series i wouldn't use it for that for the reasons already cited before.
    i'd also be curious to know how you acquired the seconds. if they were given to you or purchased, discounted extra low or not. address that answer directly to me at n3ghx(at)yahoo.com.
  • System2
    System2 Posts: 6,290 admin
    Re: best way to repair solar panel

    neil,

    I think he is referring to cosmetic blems, 95 percent of my 2480 watts of panels are just that and they are less money to purchase. I have not seen much of any degradation in output from these panels. Neil, I am also a ham too. :-D
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: best way to repair solar panel

    very good richard. i sent you a pm and would like to hear more on these blems.
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: best way to repair solar panel

    yes that's what i was getting at, but i didn't go into the details you did. :-)
    it is also true that some seconds or blems have defective silicon wafers. ie the doping didn't take place or not in the right amounts and possibly the firing of the wafers didn't go right, etc. no sg wasn't really educating me or you either apparently. :-o
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: best way to repair solar panel

    hey jon don't even start with mines bigger than yours. :-o :-o :-D :roll:
    don't get me wrong here as i don't begrudge bill his bragging rights as to his knowledge, but sue me as i flaunted some of mine too. :-P :wink: :-)
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: best way to repair solar panel

    my first comment about bigger was meant to be funny down there (or up there for those not registered). i will second the last part of your comments. we are liken to great foot racers waiting for the batan to come their way. hopefully we'll fully grasp it one day and take off with it. some have made it down the raceway somewhat, while others lie in wait for their turn. why do i even talk like this as i probably confused several hundred people? :? :? :? :|
  • System2
    System2 Posts: 6,290 admin
    Re: best way to repair solar panel

    Just a small note if it helps anyone....ive seen that high transmissivity glass that panel manufactures use is not all that it touts.Im using crystal clear plexiglass 1/4" for my surfaces and it reduces sun transmission by only .2 in volts(doesnt seem that big a loss to me).It may fade or yellow with time but i favor that in 25$ replacement costs compared to 180$ for lo-iron hi silicone glass if that breaks.. and replacement cells for a string?If you break one in series and it is shattered,if you can't get a replacement to solder on,maybe just clear it off the string and live with 8.Cut the leads and just solder it together.
    Ive seen other boards where people have tried metallic epoxies and it resulted in shorts or the string went dead.Not sure if you have encapsulated cells but one thing is for sure,dont leave broken pieces on the panel that contact each other--that will cause a short for sure....anyway doubt it helps but thought id add it......
  • System2
    System2 Posts: 6,290 admin
    Re: best way to repair solar panel
    arkiejon wrote:
    After the hail storm I had a 24 watt panel broken. Two large impacts about 1/4 the way up from one end. As I remember it did put out 23.6 volts but I don't remember how many amps.. I tested it today in bright sun and it puts out 19.4 volts and 1.34 amps. That is 25.99 watts. Being it is still working pretty good and the insurance has paid me for it I guess I need to fill the holes in broken glass. I guess I'll try Wayne's idea and get some silicone II from home depot. Unless someone has a better idea.

    Unscrew the edging and replace it with plexiglass 1/4" reseal it and hail is no longer a problem.
  • James
    James Solar Expert Posts: 250 ✭✭
    Re: best way to repair solar panel

    just a thought...
    the silicone sealant used to assemble fish aquariums is a low acid type that cures a bit differently so as not to release acids. this may be an option. although i have no panel repair experience, i had thought i would use it to seal the panel i want to construct as a project.
  • System2
    System2 Posts: 6,290 admin
    Re: best way to repair solar panel

    You're right about the acid. Regular silicone releases acetic acid while curing.
    However, RTV silicone and also "Silicone II" does not.
    Just a note on Silicone II, I've run into a few tubes of it that wouldn't properly cure. Stayed a sticky goo, even after a couple of months. Perhaps it was too old, or perhaps it had been frozen, or perhaps it was defective, I don't know, but it was newly purchased by me, never opened.
    Haven't run into that with RTV, but I find it not nearly as strong as the regular stuff.
    Perhaps try some out of a Silicone II tube to be sure it cures OK, before putting it on the PV, as it's VERY difficult to remove the crap if it doesn't cure. Been there, done that.
    Wayne
  • System2
    System2 Posts: 6,290 admin
    Re: best way to repair solar panel

    Greetings,
    For the glass repair I would use Lexan. It is much stronger than the plexiglass and doesn't yellow or fade. You can buy it pretty cheap at both the big home stores. Also, regarding the knowledge debate, remember, "its what you learn after you know it all that counts".
    Tek
  • System2
    System2 Posts: 6,290 admin
    Re: best way to repair solar panel

    Also, you can cut Lexan with a saw and also drill it. You can't do either with Plexiglas, at least with what's delivered to us here as Plexiglas, - it just shatters. To "cut" our Plexiglas, you must gouge a line, over and over until it's quite deep, then crack\break it on that line. Lexan is highly resistant to impact. Plexiglas in not.
    Note: Silicone doesn't adhere well to either.
    Wayne
  • System2
    System2 Posts: 6,290 admin
    Re: best way to repair solar panel

    Greetings,
    With regard to the sealant on lexan, I would reccomend windshield urethane. It's pricey at $11 a tube but sets very fast and will hold up to anything. You can get it at any automotive paint store.
    Tek