DIY Solar Panel

This DIY solution will help you build a solar panel array that produces about 18 volts of power for under $200. After learning the techniques involved, the design could be improvised to produce more power easily by upgrading the solar cells.

Via Home Solar and Wind Info

Building your own diy solar panel 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 panel and save a ton of money over what you would pay for pre-built panels.  I built my own DIY solar panel in a weekend and this article will 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.  If you are going to go with the simplest design using a wood container like I did, 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 your own diy solar panel is to obtain solar cells.

The standard 3×6”solar cell generates 0.5 volt and about 3.5 amps.  Most people build panels that output 18 volts.  Therefore, 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 ebay.  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.  108 cells will produce 3 36 cell panels.  Stay away from 100 cell lots if you are going to be building the typical 36 volt panel.  If possible, buy cells that are already tabbed.  It will make the wiring later 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.

Building A Container

Your diy solar panel needs a container to hold the cells. You can build a box to hold the cells out of many different kinds of material.  The easiest for most people to work with is wood.  Decide on the layout you’d like for your cells and figure out the dimensions you’ll need for the box to hold the cells.  Plywood works fine for the back and ¾” square wood for the sides, but you can use whatever you happen to have.  You’ll need some additional wood to put into the box to attach the cells to called the substrate.  Again, you can use whatever you happen to have around like cheap fiberboard.  Cut this to fit inside the container box.  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 the cells are glued in place, you need to wire the cells together.  Wiring 36 cells together in series will give the 18 volts that we are looking for.  Buying pre-tabbed cells will make this much easier as you can just solder together the tabs.  If you didn’t buy pre-tabbed cells you will have to solder on tabs before you glue down the cells.  Buying pre-tabbed cells saves the time of soldering on all the tabs.    Depending on how you plan to use your panel you may want to solder on a diode.   A diode will allow power to flow in only one direction, in this case out of the panels.  If you have your solar panel connected to batteries, at night when there isn’t any sunlight power can actually flow backwards from the batteries into the solar panel, draining power that you stored in the batteries during the day.  Installing a diode will keep this from happening.  However, most charge controllers include this feature already so if you plan to use a charge controller and not connect the the panel directly to batteries, a diode is unnecessary.

Attaching The Cells

Now you will need to attach the cells.  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.  Lay out all the cells in the layout you decided on and glue each cell in place and allow the caulk to dry and set.

Final Construction

There are only a few more things to do.  First is 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.  Then 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.

Testing

Take the panel out into direct sunlight and bring a voltmeter.  Hook up the voltmeter to the panel and you should read something between 18 and 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 do it 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.

The Guide I Used

I actually ended up buying a bunch of DIY solar panel guides and the best one was GreenDIYEnergy. It is the most comprehensive with over 200 pages of ebooks and 6 DVD quality videos that cover the entire build process from start to finish step-by-step.  When I built my solar panel I followed along with the videos and at the end of the weekend, my solar panel was finished. If you’ve been thinking about building your own solar panel, I suggest you give it a try. If I can do it, you can do it too! If you decide to give it a try, I also highly recommend GreenDIYEnergy. By following it’s step-by-step videos, anyone can build a DIY solar panel and save a lot of money.

Hat Tip PuppetGov