The bulk of the cost of installing a solar electric system is in the solar panels themselves. Prefabricated panels run upwards of $1,000. The actual design of a solar panel, however, is not especially difficult, and with minimal knowledge or carpentry and electrical work, you can build your own solar panels for a fraction of the cost of buying prefabricated panels.
Solar Cell Array
Lay the solar cells face down on the plywood in rows of six.
Solder each cell together in an array, using separate copper wires for the positive and negative poles to make the connections. Start from the top left cell and end with the bottom left cell touching each solder point. Be careful not to damage any of the cells and be sure to leave enough excess wire to attach the blocking diode and electrical jack to later.
Test the array with a voltmeter the ensure it is functioning properly.
Place a dab of heat-resistant adhesive on the back of each cell, set the Masonite pegboard directly on the cells so that it covers all of them. Flip the entire arrangement over so that the cells are resting on the pegboard and you are free to work with the plywood.
Cut off any any excess pegboard.
Using the 3/4-inch by 3/4-inch lumber, create a frame around the entire perimeter of the plywood.
Carefully set the pegboard with the cells attached to it inside the frame and secure it to the pegboard.
Cut a notch in the frame for the extra wire from the solar array to pass through.
Solder the blocking diode and electrical jack to the excess wire sticking out from the frame. Be consistent in your wiring and ensure that the positive wire is soldered to the positive connection on the blocking diode and jack and the negative is connected to the negative. The positive and negative connections will be indicated on the diode and the jack. Be sure to retest the array before adding the jack.
Cover the entire panel with Plexiglas, secure the Plexiglas to the frame and seal all of the edges around the Plexiglas with silicone caulk.
The biggest cost you will incur when building a solar panel is the cost of the solar cells. Mono-crystalline cells typically run about $6 each as of 2010, putting the initial cost of the cells, assuming you don't break any during construction, at $216. To reduce the cost of your solar panel, you can acquire slightly cracked or chipped cells from manufacturers or through online auction sites for a fraction of the cost. These damaged cells will produce slightly less electricity but once they are all soldered together in an array, the loss is not significant.
Things You'll Need
36 mono-crystaline solar cells
45 3/4-inch by 22 1/4-inch piece of plywood
45 3/4-inch by 22 1/4-inch piece of Plexiglas
3/4- by 3/4-inch wood molding, 135 inches in length
Masonite pegboard approximately the same size as the plywood