I experimented with putting plexiglass covers over both halves of the panel, but in the end decided not to use them, so those steps are omitted from this Instructable. You can see the mistakes I made, and the omitted steps, and lots more about constructing this solar panel on my web site. See also my home-built wind turbine and home-built biomass gasifier alternative energy projects while you are at my web site.
Here is a video walk-around of the finished solar panel. This Instructable will explain how I built it.
Step 1: Getting the Solar Cells
My first solar panel used 3 X 6 inch monocrystalline silicon solar cells. They are highly efficient and produce a lot of current. But they are also big and delicate and difficult to work with. For this project I decided to use a different kind of solar cells. I used 40 thin-film Copper Indium di Selenide (CIS) solar cells. Each cell is actually a miniature solar panel 60mm x 60mm x 2mm thick, that will produce a little over 4.5 Volts and 80 mA in bright sunlight, that only comes out to about 0.375 Watts per cell, but 40 of them together produce the 15 Watts I was targeting. I would wire them together in groups of 4 cells in series to get about 18 Volts, and then wire the groups of 4 cells in parallel. I would divide the 40 cells into two groups of 20 and build a folding box to mount them in. I bought 40 of the (CIS) solar cells off of Ebay and got to work.