Today we continue our series of articles on how you can slash your electricity bills by making your own homemade solar panel out of readily available materials. You can get into this exciting technology without spending a fortune – in some cases, you can scrounge everything you need to get started. In part 3 of the series, we will take our solar panel housing we made in the part 2 article and get down and dirty with mounting the solar cells onto the substrate.
And now a brief lesson on electricity and different ways of wiring electrical components up – don’t worry – it’s very easy. If you are following the suggested sizing presented in this series and are building a solar panel array with 36 solar cells within it you will achieve about 18V from your panel from the 0.5V or so you will get from each cell, and 18V will be great for, say, charging a 12V battery. To get 18V from the panel each solar cell must be wired to it’s neighbors in series connection, which means the positive or + from one cell is wired to the negative or – of the next. At each end of your string of cells you will have one free positive wire and one free negative wire, and the voltage between these two wires will be about 18V when the panel is active. The other method of electrical connection other than series connection is parallel connection, and you might need this if you plan on connecting together finished panels so that you still only have 18V but also have more current (measured in amps) produced by your setup. To connect panels in parallel you will connect the positives (+) together and the negatives (-) together of each 18V solar panel.
Now, back to the action. Depending on the particulars of your solar cells that you have purchased (or scrounged), it may be easier to wire the cells together in series connection before mounting them onto the substrate. If this is the case, make sure you leave enough wire between the middle two cells in the series (between solar cell number 18 and number 19) to cover the distance between the top area of the solar panel housing and the bottom area underneath the central strengthening crossbar. Mount the solar cells individually onto the substrate using one dab of silicone caulk per panel in the middle on the back of the cell. Don’t spread silicone caulk all over the solar cell or all over the panel, because the expansion and contraction of the solar cell with temperature may very well crack the cell if it is glued in more than just one central point.
Make sure you allow at least 24 hours for the silicone caulk to cure completely before any further steps. We are almost done! We just have a few final steps and our fully functional, low cost, solar panel is finished and ready to usher in a new age of cheap available power. During the next article we will put the cover on, finish up the wiring, test the solar panel, and talk about a few options for using your new solar power generation setup, and also improvements you can make for your next project.