Build Your Own Solar Panel

To build your own solar panel start by building a shallow box or frame. I used 1/2 inch plywood just because I had a piece on hand. You could use 3/8 inch plywood instead of 1/2 inch. The 3/8 would make the solar panel a little lighter. I cut the plywood 28 inches by 35 inches. This size frame will accommodate the 36 solar cells that are 3 by 6 inches. The sides and ends of the box are 3/4 by 3/4 inch wood strips. I used wood screws to fasten the sides and ends to the plywood. Next cut a peice of pegboard 26 by 31 inches. Cut 3 strips of pegboard 1 inch wide and 31 inches long.

Pick an end that will be the bottom of the solar panel and drill 4 or 5 1/4 inch holes through the 3/4 inch strip. This will allow some ventilation in the solar panel once the solar panel is sealed up later in this project.

When you build your own solar panel paint the plywood frame, the pegboard, and the one inch strips with at least two coats of exterior paint.

Make sure to paint both sides of the plywood frame, pegboard, and the strips.

Once the paint is dry position the three strips equally in the frame.

Now position the pegboard on top the three strips. Center the pegboard inside the frame. Use wood screws to fasten the pegboard and strips to the back of the frame. I used four screws per strip.

If you look at the end of the frame at the bottom of the picture you can see the 1/4 inch holes that was drilled for ventilation.

The reason I used pegboard and the strips is the holes in the pegboard and the strips and the vent holes drilled in the end allow some air around the solar cells. Once the panel is sealed up and placed in the direct sun you don't want the panel to build pressure up inside from the heat because this pressure could cause some distortion to the plexiglass cover, causing it to leak.

Here are the 36 pretabbed solar cells I bought off ebay, I bought the 36 cells, extra tabbing wire, buss wire, solder, and flux pen and received two bonus cells for 79 dollars.

VERY FRAGILE be very carefull when handling. These cells are whole cells and measure 3 by 6 inches. Before you buy solar cells make sure you get whole cells and not broken or cracked cells. I would recommend the pretabbed cells because there is less soldering to be done when you build your own solar panel.

These cells are rated 1/2 volt and 1.75 watts each. We are going to connect them in series and if you do the math 36 cells times 1.75 watts equals 63 watts. Then multiply 1/2 volts times 36 cells equal 18 volts. We will use this solar panel to charge a 12 volt battery and connect it to a real usable load.

Rule of thumb, when you build your own solar panel you want your solar panel to output 1 and a half times your supply voltage. 12 volt system you want 18 volts, 24 volt system you want 36 volts and so on.

The blue side or sunny side of the cell is the negative, it has two bus bars with the tabbing wire connected to them. The bottom side of the cells are the positive side, there are two rows of three solder tabs. This is where you will connected the negative from one cell to the positve of the next cell. Just like batteries in a flashlight, negative to positive to negative and so on.

Here is a diagram of the solar cells connected in series.

Build your own solar panel will consist of 4 rows of 9 cells. The first cell of each row we will connect two six inch pieces of tabbing wire to the bottom or positive side of the cell.

Build your own solar panel by soldering the six inch tabbing wires to the bottom side of the first cell leaving the sunny side down I placed the second cell sunny side down next to the first leaving a 1/4 inch space between them. I continued soldering the cells negative to positive until I had nine cells connected in series. The nine cells are up side down and I had an extra set of hands help flip them over and into the frame.

Here you can see the end of the first row, the blue cell. The tabbing wire hanging off the end is from the negative or top side. The cell turned sunny side down will be the first cell in the second row. You can see the six inch tabbing wire soldered to the positve connection. We will connect eight more cells in the second row.

Here we are finished with the second row. As you build your own solar panel repeat the same steps for row three and four. What we wind up with is four rows of nine cells all connected in series. When you finish soldering together a row of cells and have them placed in the frame you should check the output with a meter to make sure that the cells are working. If they are, carefully lift the row of cells on there edge and place a small dime sized amount of silicon in the center of the back of each cell and set that row in place on the pegboard.

I have placed a page on soldering tips in the navigation bar and in the table of contents on the home page.

Here is a diagram that shows the complete connections of the build your own solar panel. You can see how the four rows of cells are connected in series. Connect the bottom of the first row to the bottom of the second row, connect the top of the second row to the top of the third row, connect the bottom of the third row to the bottom of the fourth row. This leaves the top of the first row positive and the top of the fourth row negative. Also note we will add a blocking diode from the positive connection on the first cell in the first row. The diode should be connected with the marked end or cathode to the red positive wire going to the battery and the unmarked end or anode connected to the solar cell.

Build your own solar panel. Here is a picture of the top of the solar panel. You can see the buss bar connections and the blocking diode. The red and black wire has a little slack in them so I tucked them behind the pegboard. I drilled a hole in the back of the panel at the top and ran the wires through it, then sealed the hole with silicon.

The blocking diode acts like a check valve, only letting current flow from the solar cells to the battery and blocking current from the battery to the solar panel. Without the blocking diode when the sun goes down the solar panel can act as a load and draw current from the battery.

Here is a short circuit load test and the solar panel has an output of 3.53 amps.

As we mentioned early we were wanting to see about 63 watts at 18 volts. If we do the math volts times amps equal watts and if we have 18 volts times 3.53 amps equals 63.5 watts.

Lets check the volts.

And there is 18 volts. The panel is working properly.

The last thing we need to do is cover the panel with our plexiglass. I drilled holes all around the edges of the plexiglass about 8 inches apart. I put a good amount of silicon on the top of the side peices and placed the plexiglass in place and secured with wood screws.

Here is a picture of the finished solar panel. I hope these instructions help when you build your own solar panel.

Build Your Own Solar Panel List Of Materials

Pegboard, plexiglass, 3/4 by 3/4 inch wood strips, silicon, and wood screws, lowes price 37.50

8 amp schottky diode JAMECO.com price .59

Wire, Plywood, Paint, on hand.

Total Cost 120.00

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