DIY Solar Panels – How To Build A Homemade Solar Panel

I created this website to show you how I built my first DIY solar panel. I go through every step of the process. I’m really proud of my homemade solar panel, there’s a photo of it just below. If you have average DIY skills it’s easy to build a solar panel and there are great guides available that go into all the necessary detail. Thousands of DIY solar enthusiasts are building similar panels and successfully constructing large arrays to power their homes. DIY solar panels are relatively cheap to build and very flexible in design.

Part 1 – Planning, Selecting the Solar Cells and Constructing the Frame

DIY Solar PanelsMost of the design features of my homemade solar panel are not original, after all how many variations can there be in a basic DIY solar panel design. However, I picked what I thought were the best design elements, added a couple of my own twists, and came up with a pretty robust solar panel for a fraction of what a new panel would cost.

I chose to build an 18V panel, one that could handily charge a 12V battery under the most overcast skies. At 0.5V nominal per solar cell that meant I needed 36 cells in series. The cell count is key to starting the design process and determines the final shape and size of the solar panel.

Step 1 – Purchasing the Solar Cells and sketching the layout on paper

Evergreen Solar CellsBefore I could draw my design and order materials I had to decide what cells I was going to use. They come in all shapes, sizes, type and price range and are the single biggest determinant of the overall design of the solar panel. I decided to take the popular route and buy some Evergreen multicrystalline 3″x6″ cells that you see for sale on eBay. I bought a kit consisting of 50 solar cells, tabbing wire, bus wire, solder and flux. These were untabbed cells (more on that later). They are a bit cheaper but involve more labor and risk of cell damage when soldering tabs.

The cells arrived well packaged and in great shape. What a relief. I had visions of opening the box to find a bunch of chipped and cracked cells. At 200 microns thick these are very delicate. I measured several cells for overall width and length and came up with a more precise size of 3 3/16 inches by 6 inches. That extra 3/16 inch on width is very significant when you line up a dozen cells, amounting to an extra 2 inches in panel length.

DIY Solar PanelsI decided to use ¼ inch spacing between cells and ¾ inch around the periphery of the frame to run bus wires. I also divided the panel into 2 sections of 18 cells each. I made a full size drawing of the layout on 24 inch wide paper so I could be sure of the final dimensions.


Step 2 – Cutting the frame materials

Solar Panel Frame MaterialsI made the frame from a sheet of 24 x 48 x ½ inch birch plywood. I cut it to 21 1/2 inches by 46 inches on my trusty tablesaw with a 60 tooth cross cut blade. The rim pieces were made from a 4 x 48 x ½ inch piece of finished pine which I ripped into ¾ inch wide strips. I wanted the panel cavity to be ½ inch deep with a ¾ inch rim width. I cut 2 strips to 46 inches and 3 to 20 inches. One of the short strips is a center divider. I drilled 3/16 inch pass through holes in 2 of the 3 short pieces to allow the panel to maintain equal pressure and humidity with the outside and to pass wires through the top and bottom sections (see holes in photo below). Note – Except for the hole for the wire pass through (see step 12), I’ve since concluded that the holes are not necessary. Leaving an open pathway from the cells to the outside environment is not a good idea and leads to accelerated cell corrosion.


Step 3 – Assembling the frame

Assembled Solar Panel FrameI then glued and screwed the rim pieces to the plywood sheet using #8 x ¾ inch wood screws and Elmers wood glue. I drove the screws from the back of the plywood sheet and into the rim strips so the tops of the rim strips remained one continuous unbroken surface. This made for a better surface upon which to lay the acrylic front face. Prior to assembly I pre drilled clearance holes and countersunk the plywood so the screws would pull the rim pieces tight. I countersunk the holes a little deeper (an extra 1/8 inch) so I could get close to 3/8 inch engagement of the screws in the rim pieces. The photo shows the finished assembly prior to painting. Notice the pass through holes in the center and bottom rim strips.


Step 4 – Painting the frame

Painted Solar Panel FrameTo give the frame a good seal from the elements I applied 4 coats of exterior grade semi gloss white paint on all surfaces. Good coverage is essential if the panel is to stand up to weather extremes for several years.


For the best guide on how to build DIY solar panels with really great videos, plus a complete list of where to buy solar cells and all the tools required Click Here. Super homemade wind turbine plans included too.

Part 2 – Cutting the Acrylic Front and Tabbing the Solar Cells