How to build a solar panel

How to build a solar panel - Introduction

 

With continually rising energy costs, plus the stress that conventional energy production puts on the environment, many people are starting to Go Green. The use of solar panels to supply a home with energy is one great answer for both issues, though the initial cost of having them commercially installed can be prohibitive. However, for the handy person who can use a few simple tools, learning how to build a solar panel is also an option. Even though it might seem like a very complex ordeal, construction of solar panels fairly easy, and much more cost-effective than having panels installed commercially.

How to Build a Solar Panel - Research!

 

Solar cells/solar wafers come in a variety of types and watts, which all dictates the amount of the sun's energy each cell can harness. Knowing that, and the amount of electricity used by a household, the number of solar cells and panels needed to power a home can be estimated.

How to Build a Solar Pane1 - 3 Standard Cell Types

There are three kinds of solar cells used for panels:


• Amorphous - Least expensive, least efficient, requires a surface of almost twice that of more efficient cells. Not recommended.

• Mono crystalline - Most expensive, most efficient, uses least surface area. Cost $4-$7 per cell.

• Polycrystalline - Less expensive than mono crystalline, slightly less efficient, still much better Amorphous. Cost $1.50 - $3.00 per cell.

 

 



 



 

 

 

 

 

 

 

 

 

 

 

 

 

 

For this article mono crystalline solar cells are used.

How To Build a Solar Panel - Materials List

1 2'x4' sheet of pegboard
1 2'x4' sheet of pressure-treated plywood, 3/8" or 1/2" thickness
1 2'x4' sheet of plexiglass
2 1"x2"x10' wood furring strips
36 mono crystalline solar cells
Wood Glue
Deck Screws
1" Drywall Screws
Silver Solder
Rosin Flux Pen
Tabbing Wire
Bus Wire
Transparent Silicon Caulk
UV Protectant Sealant (like deck sealant), white or light color

Tools Required
Drill
Drill Bits
Hand Saw
Paint Brush
Caulk Gun
Soldering Iron w/flat tip - 40 to 65w
Scissor (for cutting tabbing wire)
Volt Meter
Junction Box

How to Build a Solar Panel Step 1 - Making the Frame

For a solar panel to be most efficient, cells should cover as much of the panel as possible and frames should have low-profile edging that will not cause shadows. Standard sized monocrystalline cells allow room for 12 cells down the board, three cells across, with a 2.5" border on the edge for the furring strips and about 1/4" between each cell. 36 cells are always required, no matter what the cell size, to make a functioning solar panel.

• Use furring strips to build a frame around edges of the plywood, laying them flat so they have the lowest profile. Using wood glue and deck screws, attach the strips to make a nice, tight frame.

• Cut the pegboard so it fits comfortably into frame. It does not need to be perfectly tight; the pegboard acts as ventilation for the solar cells.

• Set the plexiglass sheet on top of the frame to make sure it fits to size, which it should, with no modification. Clamp plexiglass sheet to the frame for drilling. Then, with a small diameter bit, carefully drill a pilot hole through the plexiglass, into the wood frame; this will help keep the plexiglass from cracking. Drill again with a slightly larger bit, gradually increasing bit size until drywall screws will fit snugly, yet still bite into the wood frame. Lastly, drill a countersink with a larger bit for a seat for the the screw heads. Once the whole sheet and frame is drilled every 4" to 6" all the way around, remove the plexiglass and set aside.

• Paint the frame and the pegboard with 2-3 coats of UV Protect ant Sealant. Make sure to paint both sides of the frame and the pegboard. Be sure to allow time for each coat to dry before applying another one.

• After all surfaces of the frame and pegboard are painted and have dried, fit the pegboard into the frame and attach securely to the plywood with decking screws. Paint over screw heads afterward.

How to Build a Solar Panel Step 2: Tabbing the Solar Cells

• Lay two cells top to bottom on a clean, flat, rigid surface face up. Measure out a length of tabbing tape that spans from the top of the first cell to the bottom of the second one, leaving 1/4" to 3/8" between them. Cut two lengths per cell. For 36 cells, 72 lengths should be cut.

• For each cell, using the rosin flux pen, apply flux down the entire line of the existing tabbing contacts that came on the cell (there are 2) to prepare them for soldering. Apply a tiny blob of solder to the top end of each contact, making sure none flows over the edge. Then, take the pre-cut tabbing tape and carefully solder ends down with the dab of solder already on the cell. This provides a means to steady the tabbing tape for proper soldering.

• Holding the strip of tabbing tape flat against the cell, over the fluxed contact tape, carefully solder over it, connecting it to the contact on the cell. Getting a flat, seamless application for a good connection is critical. This may take a little bit of practice. Do both strips on the cell. Repeat the same thing for all 36 cells.

How to Build a Solar Panel Step 3: Connecting Tabbed Solar Cells

• Once all 36 cells have their two tabs securely attached they need to be strung together. Lay 12 cells face down in a long line on a clean, flat surface (soldered-on tabbing tape will be underneath), but with the extra lengths of tabbing tape brought up to the top, overlapping the next cell in the line. The cells have square tabbing contacts on their backs, rather than strips.

• Flux each square tab contact, then proceed to solder the tabbing tape from the front of the first cell to the back tab contacts of the second cell, leaving 1/4" to 3/8" between them. All of the tabbing tape should now be attached, with the front of Cell #1 soldered to the back of Cell #2, except for two 'leads' coming off the last cell in the line. Do not cut those off!

• Repeat until 12 cells are soldered together to make one long chain. Create 2 more chains of 12 cells each the same way.

How to Build a Solar Panel Step 4: Arranging and Wiring Solar Cells on the Frame

• There are now 3 strings of 12 cells each. Arrange them on the frame. Place all three strings face-up, spacing them so they are evenly placed to make straight rows. Take the middle string and rotate the whole thing in the frame by 180 degrees to change the direction of current flow. Once they are again evenly placed, carefully put a blob of clear silicon caulk on the underside of each cell IN THE CENTER ONLY and gently affix to the pegboard. Don't press too hard as the cells are fragile and could crack. Do this until all 36 cells are affixed, making 3 neat rows.

• Connect the three strings together with some bus tape, which is thicker than tabbing tape to carry more current. Starting with the upper left tile, go to the bottom of that string and solder a bus wire onto those two tabs, spanning to the cell on the row next to it (the row that has been rotated). Solder a tabbing wire "lead" to the tabs on that cell if necessary, extending the tabs, then use those to solder to the bus wire. The bus wire should be soldered to 4 tabs, connecting to the two cells.

• Follow the second string back up to the top and solder in a bus wire from the tabs sticking up on that cell, to the top cell on the third string. Those two connections are all that's needed. At the last cell in the last string, tab wires should be soldered together with a length of bus wire, completing the circuit.

• Set the panel in the sun for a while and test it with a voltmeter to make sure it works. If there is a reduced wattage reading, check to make sure strings are actually wired negative to positive to negative.

• Wiring from the bus wire at the end of the circuit, connect to a junction box that can be placed on the back of the panel. Drill a hole through the frame to put the connecting wires through, then seal the hole with silicon caulk.

How to Build a Solar Panel Step 5: Sealing the Panel

• Now that everything is finished and working, screw the plexiglass cover back into place and test the panel again. If all seems well, the panel can be sealed silicon caulk and allowed to dry. The solar panel is ready to be used by being wired into a battery or controller.

 

Besides what is listed abovethere are many other types of solar cells which we will update this article on How to build a solar panel at Energy-Geek.com. For another method try this method on How to Build a solar panel from Ehow.