pic's pf e-bay solar cell assembly

[picmacmillan]

pictured below is the ebay cells you can buy for about $35 per pound.

The soldering goes to the back and is a little tricky at first, but well worth the effort

we then hang them on some nails that are the same distance as the lead wires(this reduces the problem of pulling off the solder from the side force or stretching)

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after we have enough to make a panel, we fit them on the glass.

Then they are ready for wiring...and that's where i am at today.....thanks are not enough to say for how much help i have had from internetfred.....there is surely a spot for a guy like him in the big alternative energy chatroom in the sky!...thanks fred......pickster

[picmacmillan]

maybe i better try and fix my photo size again! and do this post again...sorry folks...pickster

[Tom in NH]

Nice pics, Fred. Maybe you considered this idea, but rejected it. Or maybe you didn't consider it.

Make a jig to properly space all the cells that go into one panel. Place the cells * upside down * in the jig. Solder the tabs down, dab them with a spot of silicone and then lay your back panel down on top of the silicone. Then you flip the whole shebang over and voila. I find it saves at least two steps of handling them, and handling them is when they break.

I've also learned a small thing after soldering umpteen zillion of these cells, if you straighten the tabs by pulling on them gently between your fingers and then bend them so they angle toward the top side (maybe 10 degrees or so), you can lay the cell down so the tabs fit on top of the previous cell and the tabs will lay nice and tight against the soldering tabs, making soldering a bit easier.

I'll try to upload some of my pictures soon.

Tom

[picmacmillan]

hi tom.....i like the upside down idea and i already do the ten degree idea...this is pickster by the way...fred just posted for me the other day cuz we were at his house....i think i will take your suggestion and do it upside down on my next panel....i am still a little apprehensive about siliconing these in the center, i feel there will be forces acting on the silicone, either in compression or tension, haven't sat down to figure it out yet...but anyhow, thanks for the infor...pickster

[pyrocasto]

If you silicone the cells onto the glass, if one breaks, how do you get them apart for repair? I would hate to break one cell and ruin that whole row.

[jimjjnn]

I just did this reply to another post.

Mylar survival blanket(non-conductive).

Smear one side with heat sink grease. Put mylar on aluminum or copper sheet. Squeegee air bubbles out or pinprick the bubbles. Smear more heat sink grease on the top side.Not real thin tho or too thick. Lay solar cells on this . Press gently(VERY GENTLY)top glass on top.

The mylar sheet will conduct heat to back plate which is always in shade.

This may also prevent moisure deyerioration of cells if heat sink grease gets on the edges of cells (Don't really know if this will work).

Might be worth a try as heat sink grease withstands some pretty hi temps in electromic equip. Used to use the outside steel housings of robot run tape drives for heat sinks with thin mylar sheeting in between.

[jimjjnn]

Almost forgot.

If heat sink grease and mylar works in a test setup, don't buy the heat grease from Radio shack(pricey!). Call electronic supply houses and ask them where you can get large quantity of the grease. Better yet, Online maybe.

[Joel]

To cut away a broken cell siliconed down, run a piece of piano wire around the dab and use it like a wire saw.

Joel

[wooferhound]

 I built a Solar panel 10 years ago and I used Silicon Tub and Tile Sealer to glue it all together.

http://www.fieldlines.com/story/2004/4/4/164552/3003

 I left some small 1/4 inch airholes on the edges, 2 on the bottom and 2 on top. Last week I decided to take it apart to clean it as 10 years outside had deposited a small layer of dust on the single large anmorphus (sp) cell inside the glass enclosure, especially near the bottom holes.

  Well ,  it was almost impossable to take apart because of the silicone sealer (although I finally did it). Was afraid of breaking the 1/4 inch glass. I would also say that it was totally airtight except for the the holes I left in there.

 So I'm recomending

Silicone Tub and Tile Sealer

[iFred]

This is in regards to why put silicon on the solar cell in the middle. If you put silicon in the middle of the cell, all the tension forces will be equal in all directions. If you where to put silicon on lets say the four corners, the tension forces will be unequal, this will cause stress on the cell and possibly crack it either  on the stressed corner area where the silicon is or somewhere where there is no silicon. This is why it was suggested to put silicon in the middle, so the tension would be either minimal or greatly reduced or none.

[Tom in NH]

Pickster, Pickster, Pickster... I am so sorry I didn't get your name right. Color me red :~)

I know what you mean about tension on the cells. I'd be afraid of putting more than one spot of silicone on, and even with one, there could potentially be some tension caused by the tabs being soldered down. I do not think this will be a problem though because there is a lot of give in the tabbing, especially on the top side of the cells.... I hope!