How to Build Photovoltaic Electric Panels

Solar panels

A photovoltaic panel or solar panel is a panel created from many solar cells. The solar cells will capture sunlight and convert this into electricity. Each cell can produce a specific amount of electricity. Take the time to determine how much power you want to produce and how many cells this requires. Before building the panels, perform a solar-site survey to ascertain that you have a good spot for the panels. This also will give you guidelines on the maximum size or your panels.

Things You'll Need

• Plywood backing
• Wood, 4 by 4s
• Solar cells
• Wood screws
• Drill
• Glue
• Silicone caulk
• Fiberglass insulation
• Peg board
• Solder iron
• Copper braid
• Fiberglass or plexiglass sheet
• Wires

Instructions

1. Sketch out the design for the panel and frame. The frame can consist of one sheet of solar cells or two different sub-panels. Determine the number of cells needed. Calculate the width and length of the panel based on the number of solar cells and arrangement. The frame needs to be slightly larger, so the cells fit inside the frame easily.

2. Build a shallow box to hold the solar cells. The box is made of the plywood backing and 4 by 4s. Use the dimensions from your design for the length of the wood. Glue the 4 by 4s to the wood backing and then screw them into place with the wood screws and drill. If the panel will have two sections then glue another 4 by 4 down the center of the box to create two different shallow sections.

3. Drill holes on the edge of the frame as vents. The holes should only be on the bottom edge of the panel. If you are building sub-panels, then also drill vent holes through the center divider. The vent holes are necessary for the panel to equalize with the outside air pressure and to allow moisture to escape the panel. The minimum diameter is 1/4 inch. When rain hits the panel it will run down and escape through the vent holes. Stuff some fiberglass insulation into the bottom vent holes.

4. Cut the peg board, so it fits inside the frame. The fit does not have to be tight. The solar cells will be mounted to the peg board.

5. Paint the frame and peg board with weather-proof paint. Apply several coats of paint to ensure the frame is completely protected. If you paint the peg board, then make sure to paint both sides, so they do not curl when wet.

6. Lay the solar cells out on the pegboard, but place them upside down. They should be placed in the positions where they will be mounted.

7. Solder the solar cells together by laying the solder tabs from one cell across the solder points on an adjacent cell. Try to match the spacing, so it is equal to your grid on the design sketch. Solder the cells in a series, so the negative tabs of one cell are soldered to the positive pads on the next cell. Use a low-wattage solder iron and a light touch when soldering. Pushing too hard will break the solar cell. Do not solder all the cells together, but create stings of solar cells.

8. Apply a small amount of silicone caulk to the center of each cell in the string of solar cells. Flip over the string of solar cells carefully. Having a friend help will ensure that flipping the cells goes smoothly. Press lightly where the glue was placed to ensure that it sticks to the peg board. Only put glue on the center of the cells and only use a little bit.

9. Connect the strings of solar cells by running a copper braid between the strings. Connect the last of the solder tabs on the string to the wire. For a three-string solar panel connect the solder tabs from string one to the solder tabs of string two. Connect the solder tabs from the other end of sting two to the solder tabs on string three. Run the copper braid around the edge of the peg board on one side. Attach the braid to the peg board using silicone caulk. There will be unconnected solder tabs on the solar cells diagonal from each other on the opposite corners.

10. Test that the solar cells are properly connected with a voltage meter. Attach the voltage meter to a free solder tab on the two corners. Place the panel in sun and make sure that a voltage is produced.

11. Drop the peg board panel into its place on the frame. Screw the peg board into place. Use a screw at each corner and one in the center of each edge.

12. Attach wires to the free solder tabs. How you connect these wires will depend on the type of solar panel you want. The wires can be connected to a series of batteries, a plug or wires into the electrical grid.

13. Glue or screw the plexiglass sheet over the frame and solar cells. This will protect the cells from the weather.

References

• "Renewable Energy Made Easy"; David Craddock; 2008
• "Proceedings of the 29th IEEE Photovoltaic Specialists Conference"; Performance and Characterization of Building Integrated Photovoltaic Panels; A. Hunter Fanney, Brian P. Dougherty and Mark W. Davis; May 2002

Resources

• Build It Solar: Solar Photovoltaic Systems