How to Make Solar Panels at Low Cost
A solar panel is really just a panel that has an array of well aligned and connected solar cells on it. The solar cells are the part that does the actual work of transforming sunlight into usable electricity. Nevertheless, it takes a large number of cells in order to generate enough power to be useful. Solar cells are rather fragile, so individual solar cells are assembled on panels. The panels will contain enough solar cells so that a usable amount of electricity can be generated. We will give you some information on how to make solar panels.
One problem with building a solar panel is finding solar cells to purchase at reasonable expense. Solar cells that are new are quite costly. Damaged and blemished solar cells are often sold on Ebay and other venues at a cost that is a fraction of the cost of new cells. These types of cells can be used to build a solar panel that will function well. This will allow you to learn how to make solar panels at a much lower cost.
You can purchase two bricks of the 3” by 6” mono-crystalline type of solar cells. It will take thirty six of these cells that are connected in series to produce a solar panel. Each individual cell will produce 0.5 Volts, so if you connect thirty six of them in series you will get about 18 volts, which is sufficient for charging batteries that are 12 volts. These types of solar cells are very thin and they are also fragile. Some sellers will coat them in wax so that they won’t be damaged when shipped, but the wax can be difficult to remove. Make sure that you purchase solar cells that are tabbed. If you purchase cells without tabs you will more than double the quantity of soldering that must be done and there is already a considerable amount of soldering. So, be sure to purchase solar cells that are tabbed.
Solar cells come in a variety of sizes; you could select smaller or larger cells to use on your panel. However, there are several points you should bear in mind.
- Solar cells that are the same type will all produce voltage that is the same, regardless of their size; therefore, the number of cells needed will be the same.
- Cells that are larger will produce a greater current than smaller cells. And the total power output of your panel in watts will be voltage x current.
Consequently, if you use larger cells, the solar panel will be able to produce more power; however, it will end up being larger and heavier. It is not a good idea to mix solar cells of varying sizes because the amount of current that can be produced will be limited to the current that can be produced by the smallest solar cell you are using.
The solar cells that we are using are 3” by 6” are have a rating of approximately 3 amperes. We will wire together 36 of them in series in order to produce about 18 volts. The entire solar panel will be able to generate 60 watts on a sunny day. The power output from the solar panels will be used to charge batteries which can be used at night when no sunlight is available.
To make a solar panel, all you really need is a shallow box. The box must be shallow so that no sunlight is blocked out when the sun is shining at an angle. You can use a piece of plywood that is 1/2” thick and 3/4” wood around its edges. The wood pieces can be secured by screws. The plywood will hold thirty six solar cells that are 3” by 6”. To make it a bit easier you can create two smaller panels that each contain 18 solar cells and then attach them both to the main panel. The measurements of the entire panel will be 45.75” by 22.25”.
Now you can cut two pieces of peg-board to fit inside of the solar panel. The two peg-board pieces will be the substrate that is used to build each of the sub-panels. It is not necessary to use peg-board any material that is rigid, thin and does not conduct electricity will work.
In order to protect your solar cells from inclement weather conditions it is a good idea to cut some Plexiglas so that it fits onto the front of your panel.
Now you can draw a grid on each of the peg-board pieces in pencil. This will be the location of each of the solar cells that will be placed on the peg-board. There will be 18 solar cells on each piece of peg-board and they will all be soldered in series, then both of the peg-board panels must be soldered together in series in order to get the voltage you desire. To solder the solar cells together place the solder tabs of one of the cells across the the solder tabs on the rear side of the adjacent cell and be sure that the space between the two cells is identical to the spacing on your grid pattern.
You should use a soldering iron that is low-wattage and a very fine solder. You can use a rosen-core type of solder. You can also make use of a rosen pen when you work on the solder points that are on the reverse side of your solar cells, prior to soldering. When you are soldering the solar cells be very careful and use a very light touch. If you apply too much pressure to the solar cells, they will break.
Now you are ready to glue the solar cells in place. You can place a small amount of silicone caulk that is clear in the center of each solar cell. Then you will flip over the solar cells and place them on the grid you had drawn on the peg-board. You will then press lightly on each solar cell in its center to get it to adhere to the peg-board.
Make sure that you don’t use an excessive amount of silicone caulk and make sure all the caulk you use is placed at the center of each solar cell. The solar cells and the panel will contract and expand along with temperature and humidity changes. Gluing the solar cells too tightly to the peg-board will cause them to crack over time. If you glue them only at the center they will be able to resist changes in weather conditions without cracking. We have provided you with a short discourse on how to make solar panels, we hope it is helpful to you and that you will be up and running with your own low cost solar panels in the near future.