Things You'll Need
1/2 volt polycrystalline solar cells, 3-by-6 inches
Voltmeter
65-watt soldering Iron
Tabbing wire
Bus wire
Lead-free solder
Flux pen
5/8 inch plywood
1 inch wide furring strips
1/4 inch acrylic sheet
silicone caulk
rubber weatherstripping
varnish

An common way for a DIY beginner to build a solar panel is to assemble individual polycrystalline solar cells into an array. Like a battery, solar cells have positive (back) and negative (front) sides. Though a somewhat tedious process, connecting a small number of solar cells can generate a significant amount of power. For example, an 18-volt solar panel, comprised of 36, one-half-volt solar cells, is capable of charging a common 12-volt battery. Properly assembled and protected, a homemade solar panel can provide years of clean, renewable power.
Assemble Solar Cells into a Panel
Step 1
Run a flux pen over the two main bus lines on the front of a solar cell.
Step 2
Cut a piece of tabbing wire twice the width of the solar cell. Lay the tabbing wire over a main bus line so half covers the solar cell and the other half hangs off the edge. Repeat on the second bus line.
Step 3
Run a hot soldering iron over the tabbing wire along the entire length of each front-side bus line.
Step 4
Flip the solar cell over and place it side-by-side with a second solar cell, back side up. Align the parallel rows of square contact points on both cells.
Step 5
Wet the six bus contacts on the second solar cell with a flux pen and drip a bead of solder on top of each contact with a hot soldering iron.
Step 6
Fold the loose sections of tabbing wire from the first solar cell over the contact points on the second cell.
Step 7
Press the tabbing wire into the solder with a hot soldering iron. When the solder melts, the tabbing wire is attached.
Step 8
Test if the solar cells are correctly assembled by placing them in full sunlight and connecting a voltmeter to the positive and negative contacts.
Step 9
Repeat until the desired array size is reached. A compact 4-by-9 cell solar panel is acceptable for a 36-cell array.
Build the Solar Panel Case
Step 1
Add 2 inches to the length and width measurements of the array dimensions and cut a plywood base to size. Drill a small hole in all four corners of the base for ventilation.
Step 2
Fasten the furring strips to the sides of the plywood to form a shadow box. Attach rubber weatherstripping along the top of the furring strips.
Step 3
Center the rows of connected solar cells face-up inside the shadow box. Secure each cell to the plywood with a dab of silicone caulk.
Step 4
Connect the rows of solar cells in series with bus wire. Leave extra lengths of positive and negative bus wire for connection to a battery.
Step 5
Cut the acrylic sheet to size and mount over the weatherstripping to create a weather tight seal. Plug any gaps in the box with silicone caulk and protect exposed wood with multiple coats of varnish.
Tip
Have a licensed electrician or city official inspect DIY wiring to ensure compliance with local codes.
Warning
Contact with improperly-wired electrical equipment can cause damage to property, serious injury or death.