DIY Solar Panel Question

cards385cards385 Registered Users Posts: 21
I am in the process of making my own solar panel out of a double pane window and a piece of plywood. My question is...should I put something over the plywood before I put the cells on it, the cells are very brittle and I do not want to break them. I was think something like a rubber like sheet or some cloth or something. Any ideas would be appreciated.

Comments

  • icarusicarus Solar Expert Posts: 5,399 ✭✭✭✭
    Re: DIY Solar Panel Question

    I might remove one layer of glass. There is no reason to have two layers of glass, and the amount of sun reaching your cells would be diminished by the second layer of glass.

    As to your question, I have no experience with home made Pv.

    Tony
  • cards385cards385 Registered Users Posts: 21
    Re: DIY Solar Panel Question

    I have removed one pane, I end up with a window pane with a 1/2 inch lip around, almost like a shoe box lid. Then I cut a piece of plywood to fit perfectly inside the frame. I just thought I should put something on the wood before the cells.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,962 ✭✭✭
    Re: DIY Solar Panel Question

    wood has a different expansion/contraction coefficient than silicon, one season and its likely your cells will all be cracked. I would never make my own, but if I did, I would use glass for the bottom as well. You could then put the sandwich on something to support the glass.

    Commercial produced panels bond the cell to the front glass and have tedlar vacuum sealed on the back
  • BB.BB. Super Moderators, Administrators Posts: 29,887 admin
    Re: DIY Solar Panel Question

    And if the panel is larger than 10 watts or so--you should mount over a non-flammable surface (bare ground, gravel, metal, etc.). It is possible for the wood (and plastic, if used) to catch fire when the copper foil solder connections fail under load.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • GreenPowerManiacGreenPowerManiac Solar Expert Posts: 453 ✭✭✭
    Re: DIY Solar Panel Question

    Perfect question. Perfect answer: Caulk.

    First, on the plywood go to Wal-mart and buy some all-purpose wood sealer for 7 bucks.
    Next seal the wood by painting on with a junky paint brush. Use a hair dryer on the hot setting and heat up the wood's surface a bit to diminish the moisture or it'll fog up on you later on.

    Once it's dried and you're ready to lay a string of cells. Lay two beads of door & window caulk rated for heat and cold about 1/4" away from the positive leads. When I'm done soldering the string on the positive side, I'll carefully flip the string onto the two lines of fresh caulk and press very lightly to seat them. Before you place the glass on top to cover them, lay another bead around it's perimeter and gently seat it so there is a 1/8" to 1/4" barrier between cells and glass. Done.
    Nature's Design & Green Energy on FaceBook : Stop by and "Like" us anytime.. Many up-to-date articles about Renewables every day.
    WWW.GreenAnything.Net    Ad free website.
    Lots of DIY Renewable Energy Projects on ETSY : Solar Panel builds, Wind Turbine builds, Rain Barrel build,etc.  
  • cards385cards385 Registered Users Posts: 21
    Re: DIY Solar Panel Question

    Would you add some rubber spacers so the cells do not touch the glass?
  • Solar GuppySolar Guppy Solar Expert Posts: 1,962 ✭✭✭
    Re: DIY Solar Panel Question

    The glass contact is very important, it cools the cells. If you make a heat box ( spacers ), the cells will run probably 30-50C hotter ... bad for the cells and bad for power it can produce
  • cards385cards385 Registered Users Posts: 21
    Re: DIY Solar Panel Question

    Thanks, I will forget the spacer idea.
  • SlappySlappy Solar Expert Posts: 251 ✭✭✭✭✭✭
    Re: DIY Solar Panel Question

    some wood is some what conductive, you might get a voltage loss if the cell tabs are in contact with the wood, I use to think that dry wood is a good electrical insulator, until I was probing around with the OHM meter and was getting a 3 volt bleed across the plywood, and 4 volt bleed on the painted side. And also, as the wood heats and cools it will expand/contract with the temp. But sense you seperated the the double pane glass use one sheet for the front, and the second sheet for the back?
  • GreenPowerManiacGreenPowerManiac Solar Expert Posts: 453 ✭✭✭
    Re: DIY Solar Panel Question

    Never had any heat problems without contacts to the cells. Of course, mine are ventilated. The top portion of my panels have several drilled ventilation holes and are screened for bugs. Also put a couple drilled holes in the very bottom too. Use the super fine cheesecloth screening. I'll then use some "J" channel from my pole barn surplus and mount it on top of the panel like a ridge vent. Covering it up helps keep the water out and any heat/moisture build up will quickly dissipate. Must keep the panel on at least 45 degree angle to keep fog-free.

    Putting glass right on top of the cells would likely crack them. If you must do this, then I would suggest laying a small bead of "Clear" drying caulk right on top of each tabbing wire to minimize the loss.
    Nature's Design & Green Energy on FaceBook : Stop by and "Like" us anytime.. Many up-to-date articles about Renewables every day.
    WWW.GreenAnything.Net    Ad free website.
    Lots of DIY Renewable Energy Projects on ETSY : Solar Panel builds, Wind Turbine builds, Rain Barrel build,etc.  
  • System2System2 Posts: 6,290 admin
    Re: DIY Solar Panel Question
    cards385 wrote: »
    Would you add some rubber spacers so the cells do not touch the glass?

    I built two panels using 1/2 inch plywood with a sheet of heavy plastic material glued to the top of the plywood. My cells are glued to the plastic material. I attached heavy rubber molding around the perimeter, placed the glass on top of the rubber, I have about a 1/4 space between the glass and the cells. I used a rubber weatherproofing tape to seal the edges.

    The plywood is sealed but I feel is not the best base material to use. I'm about to build two more panels, these panels I will use Hardie Plank for the base instead of plywood. My panels measure 40X40 inches..
  • GreenPowerManiacGreenPowerManiac Solar Expert Posts: 453 ✭✭✭
    Re: DIY Solar Panel Question

    3Blonds,

    Let us know if you have any issues with this fogging up.
    Nature's Design & Green Energy on FaceBook : Stop by and "Like" us anytime.. Many up-to-date articles about Renewables every day.
    WWW.GreenAnything.Net    Ad free website.
    Lots of DIY Renewable Energy Projects on ETSY : Solar Panel builds, Wind Turbine builds, Rain Barrel build,etc.  
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: DIY Solar Panel Question

    As Guppy, I would not build my own, but I would lose the plywood.

    If you mount them with small about of RTV on four corners of cell to glass then seal the back with plastic you probably stand the best chance of keeping moisture out.

    Only real way to keep condensation from happening is have no air in the cell area. This requires vacuum lamination seal which is why I leave it to commercial panel manufacturers.
Sign In or Register to comment.