Homemade Solar Panel

[RCpilot]

This is the beginning of my Solar Powered Project. I made this panel from 36 Powermax 6 inch round cells. They have a 6 amp rating but I haven't been able to get more than about 5.5 amps out of them and some a bit less. But the price was right at $6 per cell. The front is 1/8" tempered glass, the back is .040 aluminum, 1/16" spacing between the cells and the back. The cells are silicone glued to the glass with small dabs on the ribbon wire. Also 1/16" square spacers between each cell. The entire assembly has 1/2" X 1/16" aluminum strip around the perimeter of the glass. The aluminum back is covered with fiberglass window screen in addition to the paint already on the back for insulation should the back somehow ever touch the backs of the cells. The entire assembly is silicone sealed and I cranked my A/C down in the house the day I sealed it to hopefully help keep moisture out. I am getting 5.5 amps Short circuit and 20.2 volts open circuit. I am building four of these to start with. More to come...

[Volvo farmer]

6. A at let's say 14V? 80W a panel (best case scenario)
   
36. cells @ $6/cell $216, plus shipping, plus glass, plus silicone, plus aluminum spacer, plus all the time to assemble, solder and glue the thing together. You've got $2.70/watt into it in just cells. And you're going to build four of them?



Here's a panel, made in a factory, with a 25 year warranty, for exactly $4/watt.

"http://www.partsonsale.com/suntech.html">http://www.partsonsale.com/suntech.html

You'd have to go MPPT on your controller to charge 12V, or 24V batteries but still...

I built 650W of homebrew panels back when the surplus Evergreen cells could be bought for a song. I know I had less than $2/watt into just the cells and I've still had problems with moisture, and the performance has been less than stellar. I can't give you any real good numbers because I'm mostly floating batteries by 1PM and my homebrew array is optimized for December performance. Still never seen more than 6A out of what should be 400W of panels @ 24V.

Not trying to rain on your parade, but I've been down this road before, with a much lower cost/amp into cells than you have. To be quite honest with you, I wish I would have spent that money on factory built panels. I shattered the top sheet of tempered on two of my panels while just trying to move them into position into the rack. Sure, they can be fixed, but more material, time, and effort go into the process.

I like homebrew as much as the next guy, but I would only do it to save money and have fun. I had fun, learned some, and barely saved money, so I sorta view it as a neat fun project. If you're doing this for learning and fun, carry on, but I bet by the end, you're upside-down on what you could have bought a quality built, guaranteed, fully encapsulated, factory-built panel for.

[wooferhound]

A very similar thread . . .

http://www.fieldlines.com/story/2007/7/25/91443/0791