Jun
2
2009
Going green and already building your own solar panels? Good for you! You might be tempted now to build your own solar cells as well.
But you need to consider carefully whether you *really* need to do it. It’s nice to say, “I built my own solar cells!” but it’s quite time-consuming and these days they can be purchased very cheaply off of eBay.
The time involvement necessary to create one single solar cell is extensive, and it pays to remember that just one solar panel can have in the neighborhood of hundreds, if not of thousands of cells, depending on the size. So, think hard ” do you really want to commit the time and effort when it might be cheaper and most probably easier, to purchase them ready-made?
But if I haven’t convinced you to just buy your own solar cells, here’s what you’ll need to make your own:
1) Copper sheet – half a square foot should do. 2) Two clip leads. 3) Micro-ammeter measuring between 10 and 50 microamperes. 4) Either an electric stove, or some type of heating plate to put on your gas stove. 5) A large jar or plastic bottle. 6) A few tablespoons of salt. 7) A bucket of water. 
Sandpaper. 9) To cut the copper, you’ll need metal shears.
First, clean the copper sheet with the sandpaper and wash both it and your hands before proceeding. Then, cut the sheet using the metal shears to the approximate size of your heating plate or stove.
Once you have your copper piece, put it on your heating plate and turn the heat to “high.” It should take 30 minutes to produce a blackened sheet, and then another 20 minutes for it to cool so you can handle it.
You’ll see black and red spots all over, after the oxide disappears.
Then, cut another copper sheet that’s approximately the same size as your first one and make sure that they can both fit into your plastic bottle or jar without touching.
Now, connect the positive terminal of your micro-ammeter to your “uncooked” copper, and connect the negative terminal to the copper piece that you heated up.
Combine the salt and heated tap water and pour it into the bottle to fill it just below the top of the sheets ” that should leave about a quarter of an inch of copper sticking out at the top.
Finally, test your new solar cell to see if it produces current in the sunlight. You should be able to see at least 10-50 microamperes of current if you did it properly.
Since copper is so inefficient compared to silicon, you’d need 80,000 square meters of these cells to power a single 100-watt light bulb. So I’d highly recommend eBay for buying cheap, manufactured silicon solar cells.
