Build Your Own Solar Panel
A Step-By-Step Guide

Build Your Own Solar Panel

Stage 1 - Tools & Materials

Prepare the tools and materials you will need for building your panel first.

Photo: Brian Dorey

You want to make sure you have everything at hand before starting the process. If you are not a particularly handy man (or handy woman :)) type and don't have all the tools immediately available, you may need to either purchase the missing ones or, more economically, borrow them from your relatives or friends.

A diy solar panel will normally consist of:

• a frame including:
  
  
  • a backing - the frame's main support component
  • a substrate - which will slide inside the backing and actually hold the solar cells
  • border strips - attached to the edges of the backing for general protection
• solar cells which will be the main "collectors" of sunlight
• wire components such as tabbing wires for solar cells and other connecting wires
• frame cover such as plexiglass

The process of building a panel will include:

• building a backing and a substrate
• tabbing solar cells with wire (for cells which are not pre-tabbed)
• connecting tabbed cells into strings
• attaching the cell strings to the substrate
• connecting the strings with wire
• attaching a cover to the panel and sealing it

So let's summarize the tools and materials that we'll need:

If your budget permits it, you can decide to choose more durable material for your backing - aluminum - rather than plywood. However, plywood is also a good choice.

Ordering stuff on the internet is often much cheaper than buying from a local shop.

Solar cells are the most important components of any solar panel. For diy solar panels, getting your solar cells from the internet is perhaps the only viable option.

Again, it is preferable to get new solar cells. If you are on a limited budget though, you can choose to buy cheaper damaged / broken solar cells but they will naturally require a lot more work and may not function at 100% of their capacity.

Build Your Own Solar Panel

Stage 2 - Build Panel Frame

Sample Panel Backing Photo: Brian Dorey

Start the process with building your panel backing and substrate.

The size of your frame will be determined by the number and arrangement of solar cells inside the panel. If each cell has a voltage of around 0.5 V and you are trying to build a panel with an 18 V output, then you will need 36 cells connected in series. This will be enough to charge a 12 V battery (that you may want to use to store solar energy).

If you are using 3" x 6" solar cells and are planning to arrange 4 cells across and 9 cells down inside your panel, then the dimensions of your frame would be as follows:

These dimensions allow for some space between the cells, as well as between the cells and the borders.

Action:

• Cut your material to size for the backing, border strips and substrate
• Glue / screw down the border strips to the backing
• Cover the backing and the substrate with 3 layers of UV protector paint (if your material is wood); give them enough time to dry properly
• Make sure the substrate will fit just fine inside the backing

Build Your Own Solar Panel

Stage 3 - Tab Solar Cells

Next, tab your solar cells with wire.

You will need tabbing wire, flux pen, solder and solder iron to tab the cells.

This is what a typical untabbed solar cell looks like:

Diagram 1:
Front of Untabbed Solar Cell

Tabbing the cells means soldering tabbing wires to the front of each cell, along the white lines (electrodes) as seen above.

This is what a solar cell should look like once you've finished tabbing it:

Diagram 2:
Front of Tabbed Solar Cell

The length of your wire ribbons should be slightly shorter than the height of two cells since the loose ends will be soldered on to the back of other cells to form a "string". You will see how to do it in the next stage.

Action:    

Before tabbing your solar cells, test them with a multi-meter to make sure they work fine.

You can do this by attaching the negative and positive leads of your multi-meter to the negative and positive electrodes of the cell (the front of the cell is negative and its back is positive).

• Cut your wire to size for all the cells you are planning to tab
• Work with one cell at a time
• Use a flux pen "to wet" the white lines of a cell first
• Take a piece of wire and apply a little solder to one half of it by carefully pushing the solder down the wire with a solder iron
• Press the soldered half of the wire very gently along the white line with a solder iron; keep moving the iron up and down the white line until the wire is properly attached

Build Your Own Solar Panel

Stage 4 - Connect Tabbed Cells Into Strings

Now it's time to join your tabbed cells into strings.

If the arrangement of your panel is 4 cells across and 9 cells down, then you will want to build strings of 9 cells each (as opposed to a panel of 3 cells across and 12 cells down).

You will need to solder loose tabs coming from the front of cell 1 to the back of cell 2, then solder tabs from the front of cell 2 to the back of cell 3, and so on.

This is the back of a solar cell:

Diagram 3:
Solar Cell Back

The white points above are the solder points to which you'll need to attach tabs from another cell.

This is what your finished string should look like (there are only 5 cells in the graphic below, just to demonstrate the point):

Diagram 4:
Front of Solar Cell String

Action:    

The diagrams below accompany the explanation.

• Take two solar cells and put them upside down (with their backs up), aligned with each other
• Use a flux pen "to wet" the six white points on the back of cell 2
• Apply some solder to each white point of cell 2 with a solder iron
• Place one wire from cell 1 over the corresponding three white points of cell 2
• Solder the wire of cell 1 gently to each white point of cell 2 with a solder iron
• Do the same for the second wire of cell 1
• Do the same for connecting the remaining 7 cells; you have now built one string of 9 cells
• Do the same for other 3 strings

Diagram 5:
Back of Two Cells Wired Together

Diagram 6:
Back of String of 9 Cells

Solar String Back
Photo: Brian Dorey

Build Your Own Solar Panel

Stage 5 - Attach Strings to Substrate & Connect Them Together

The next step is to attach the strings to the substrate, and then connect them together with wire.

You can start by gluing the strings to the substrate with silicone caulk.

Before doing it though, you'll need to know how to actually arrange the strings on the substrate.

We assume that your arrangement is 4 cells across and 9 cells down in series (36 cells in total).

Have a look at the illustration below.

The negative wires coming from the front of string 1 will be connected to the positive wires coming from the bottom of string 2, with thicker wire called the bus.

Diagram 7:
Two Strings Connected Together

Here is a schematic presentation of the strings' arrangement in your finished solar panel (4 cells across and 9 cells down):

Diagram 8:
Connection of Strings in Solar Panel

So, this is exactly how we should position the strings on the substrate in order to connect them correctly with wire afterwards.

Action:    

Attaching Strings to Substrate

• Place your strings on the substrate, in the correct position as demonstrated in Diagram 8 above
• Flip one string over, with its back facing up and front facing down
• Drop a small blob of silicone caulk in the middle of each cell
• Flip the string over again, with the front facing up now as it should be in the finished panel
• Secure each cell to the substrate by gently pressing with your finger in their center
• Do the same for other strings

Connecting Strings Together

• Cut the bus wire into strips to connect the strings at each "turn" point
• Place one strip of wire along the two cells leading off from two strings you are trying to connect
• Wrap the tabs from each cell around the wire
• Solder the tabs to the wire for better connection
• Do the same for other "turn" points; in total you should have 3 connections like that - 2 at the top and 1 at the bottom of the panel - as demonstrated in Diagram 8

Two Strings Wired at "Turn" Point
Photo: Brian Dorey

Build Your Own Solar Panel

Stage 6 - Secure Substrate to Panel & Attach Cover

You are now ready to secure the substrate to the backing, and attach a cover to the panel.

Action:    

• Fit the substrate inside the panel backing
• Screw the substrate carefully to the backing
• Connect the two tabs coming off from each of the two cells - one located in the bottom left-hand corner ("negative") and the other in the bottom right-hand corner ("positive") of Diagram 8 above - with copper braid (as opposed to bus wire)
• Make sure the two wires that you will use for this purpose are long enough to go out into the back of the panel for external delivery of energy
• Install a blocking diode into the positive wire to prevent your batteries (which store energy) from discharging at nights, unless you use a charge controller
• Drill a hole in the bottom center of the substrate and the backing (between the negative & positive leads - as shown in Diagram 8) and let the two wires slip through this hole into the back of the panel
• Test the panel to make sure it works fine before sealing it (see Stage 7)
• Secure the wires to the substrate with silicone caulk to prevent them from moving around the panel
• Fill the hole with silicone caulk as well to keep it properly sealed
• Allow the silicone to cure completely for a day or so before sealing the panel
• Cover the panel with plexiglass & screw it with stainless steel screws
• Seal all the spaces between the backing, its borders and the cover with silicone caulk for complete protection

Solar Panel Covered With Glass
Photo: Brian Dorey

Build Your Own Solar Panel

Stage 7 - Test Finished Panel

Test the panel to check if it works as expected.

Action:    

• Place your panel in full sun
• Attach your multi-meter's negative lead to the negative lead of your panel and the multi-meter's positive lead - to the positive lead of your panel, correspondingly
• Test your voltage output first: your panel of 36 cells (0.5 V each) should produce around 18 volts
• Test your current output second: your panel should produce around 3.5 amps

Example of Finished DIY Solar Panel
Photo: Brian Dorey

You now have a fully functioning solar panel with a power output of around 60 watt.