Building your own diy solar panels is easier than you probably think. With the right knowledge, a few simple tools and enough drive, virtually anyone can build their own diy solar panels and save a lot of money over what you would pay for pre-built panels. I built my first DIY solar panel in a weekend and I’m about to tell you how I did it.
I bought a guide called GreenDIYEnergy to help with the project. It contained lists of parts, where to get them and the part I liked best, step-by-step videos. Following along with the videos made the project much easier to complete.
Tools You Will Need
You will need some basic tools to build your diy solar panel. First, you will need basic woodworking tools like saw, drill and screwdriver. You will also need silicone caulk and wood glue. For the wiring, you will need wire cutters, wire strippers, a soldering iron and solder. You can pick up most of the tools at your local hardware store. Radio shack sells soldering irons and solder.
Obtaining Solar Cells
A solar panel is really nothing more than a bunch of solar cells in a container of some kind. The first step to building diy solar panels is to obtain solar cells.
A standard 3×6 inch solar cell generates half a volt and about 3.5 amps. Most people build diy solar panels that output 18 volts. To do this, you will need 36 cells per panel. Wired in series, this will provide about 18 volts and 3-4 amps of power in direct sunlight.
The easiest place to get solar cells is Amazon. Do a search for “solar cells” and look through the results for an auction with good quality cells and enough cells for the number of panels you wish to build.
Be careful of “grade B” or other lesser quality cells. These cells typically have broken corners, blemishes or other problems that keep them from being sold as good quality new cells. If you can find them cheap, these lesser quality cells can be a good deal, though they will generally produce less energy than good quality, whole cells.
Cells are usually sold in lots of 36, 100 or 108. Stay away from 100 cell lots if you are going to be building the typical 36 volt panel. A set of 108 cells will be enough to make 3 standard 36 cell panels. I also recommend buying cells that are already tabbed. “Tabs” are the thin pieces of metal attached to the cell for wiring them together. Buying pre-tabbed cells will make the wiring much easier. It is worth paying a little extra to get pre-tabbed cells.
I bought 36 3 x 6 pre-tabbed cells from a large seller on ebay with lots of positive feedback. My cells came with solder, flux and extra tabbing. I also received a few extra cells, which I didn’t expect, but it came in handy because one of the first things I did was break one of the cells as I was separating them! The cells are fairly fragile so be very careful when handling them. You should also try to avoid getting fingerprints or dirt on the front of the cells because it will reduce the power output.
Building A Container
First, you’ll need some wood to attach the solar cells to called the substrate. You can use whatever you have laying around like cheap fiberboard. Make a 3×6 inch template with a piece of paper and draw out where you cells will lay on the substrate. After you have things drawn out the way your want, cut the substrate with a little room around the edges.
Your diy solar panels need a container to hold the cells. You can build a box to hold the cells out of many different kinds of material like wood or aluminum. The easiest for most people to work with is wood. Use your substrate as a guide for how big you need the container to be. Plywood works fine for the back and ¾” square wood for the sides, but you can use whatever you happen to have.
There are some sellers on eBay that sell aluminum frames for diy solar panels. This can also be a good option and the aluminum will hold up to the elements better than wood. It is also more expensive, though, so for your first panel you can go with wood if you happen to have it laying around or are concerned about working with metal.
You will also need a clear cover for the box. Plexiglass or lexan are best for this. Cut it to cover the box. After cutting all the wood, you’ll need to paint it and screw it together. You should also drill a hole for the wires to exit the box.
Wiring the cells
Now that you have a container, you need to wire the cells together. Wiring 36 cells together in series will give the 18 volts that we are looking for. If you bought pre-tabbed cells, you can get right to work. If you didn’t, start by soldering tabs on each of the cells.
Standard 36 cell panels with 3×6 inch cells are usually in a 9×4 configuration, meaning you want 4 columns of 9 cells each. Solder together 9 cells in a column leaving a small gap between each cell. The tabs go from the front of one cell to the back of the next.
The soldering is super easy and will go fast once you get the hang of it. This is a great first soldering project because it is so easy. Put the cells face down on the table and bring the tab from the front of one cell to the back of the next one. There will be metal squares or pads on the back of the cell. Press the tab down on the metal pad with the soldering iron to heat them and then press the solder on the tab. The solder will melt and attach the tab to the pad. If you aren’t experienced at soldering, make sure you heat the metal and apply solder to the metal. Do not heat the solder. If you end up with the tab connected to the pad and nice shiny solder, you’re doing it right. Keep going until you have 9 cells in line like this.
Attaching The Cells
Now you will need to attach the cells to the substrate. Some silicone caulk will work best. Be sure to apply just enough caulk to the middle of the back of each cell. The wood will expand and contract with heat so using a single dot of caulk in the middle of the cell will allow the wood underneath to expand without problems. Putting caulk at each corner, for example, wouldn’t allow the expansion to happen without damaging the bond.
I put caulk on the backs of each cell in a column of 9, then picked the whole column up by the tabs at the top and carefully laid the column down on the substrate. My daughter helped me keep everything lined up properly as you can see in the picture. (This is a great project to do with your kids, by the way!) These are homemade solar panels so the gaps between cells and the columns aren’t precise. I don’t think it had any impact on power output so don’t think you need to be perfect.
After the cells are attached so the substrate, finish the wiring by using extra tabbing or wires to attach the 4 columns of 9 cells in series. To know what to attach to what, visualize all of the columns connected together in one big column. Remember which tabs would be connected together in this arrangement and make the same connections in the 4 columns of 9.
There are only a few more things to do to complete your diy solar panels. First you have to drill a hole through the bottom of the container for the wires to come out. You should use caulk to fill in the hole after you put the wires through to keep moisture out. Next, glue the substrate with attached solar cells into the container. Finally, screw your plexiglass down on top of the container. It is also a good idea to solder a connector on to the end of the wires. What kind of connector depends on what you intend to connect your panel to.
Take the panel out into direct sunlight and bring a voltmeter. Hook up the voltmeter to the panel and you should read about 18-20 volts. If you get something in this range, congratulations – you have just built a DIY solar panel!
How much did it cost?
The parts for my solar panel cost $129. I actually paid a little extra for pre-tabbed solar cells and I had to buy all the wood. If you have some scrap plywood laying around and tab the cells yourself, you could easily build diy solar panels for under $100. I checked around on the internet and I saved between 50% and 75% versus buying a pre-made solar panel. I’m very happy with how my panel turned out and how much I saved by building it myself.