Homemade solar cells
Posted by Solar energy guru | Filed under Solar panels & photovoltaic cells
Solar cells take energy from the sun and convert it into power; several solar cells put together can be used to make solar modules, which in turn can be assembled to make solar panels. Solar cells are most recognized by the devices used to power calculators, but we can actually make these in our homes. Solar cells incorporate photovoltaic energy, the scientific term for the power from the sun, light or otherwise.
As the global energy source shrinks and environmental concerns are on the rise, solar power has exponentially grown in popularity in recent years. The best thing about power from the sun is that it’s free and unlimited in supply. We need only create and use devices that harness this power. You can make a solar cell in about an hour in your kitchen, and the key ingredient is cuprous oxide, an oxide of copper, which takes the sun’s energy and flows it directly into your device of choice. Your first step is to go to your favorite hardware store and stock up on copper flashing (one sheet), two alligator clip leads, and a micro ammeter. You also will need an electric stove, a clear plastic bottle, salt, tap water, sand paper and sheet metal shears.
First trim the copper sheeting to about the size of a stone burner, wash hands and the copper sheet, then sand the copper plate to remove it of any sulphide and corrosion. Place this clean copper sheet on the burner, and turn the stove on to its highest setting. The sheet will then oxidize, and you will see various colors spread throughout the copper sheet. Keep the copper sheet on the stove long enough for the multicolored oxidation patterns to be covered with a black layer, signaling the presence of cupric oxide that will later peel off. Keep heating the copper plate at this phase for 30 minutes, so as to generate a thick layer of the cupric oxide.
Turn off burner, and let copper sheet cool on the burner. You want to cooling to occur slowly, so do not remove the copper sheet from the burner. You will notice that the copper sheet will shrink as it cools. The black layer will cool as well, but at a different rate, which will cause it to flake off. They fly off in a popping motion. Let the copper plate cool for about 20 minutes, until it reaches room temperature. Rinse the copper plate to remove any excess cupric oxide, gently scrubbing the plate with your hands.
Finally, cut out another copper sheet that’s the same size of the oxidized one, and fold both to fit into your plastic bottle. The copper sheets shouldn’t touch, and it’s best for the oxidized side of the treated copper sheet to face the sheet. Affix the alligator clip leads, one each to the copper plates, then connect the lead from the untreated plate to the positive terminal of the meter. The treated copper plate should be connected to the negative.
Next, make saltwater with hot tap water and two tablespoons of salt. Pour into plastic bottle, avoiding wetting the alligator clip leads. Do not completely submerge the copper plates; keep about an inch of them above water. The copper oxide will now act as a semiconductor in the sunlight. Electrons will move through the water, to the copper plates, then through the wires to your meter. Each cell products 0.25 volts or 50 microamps. It takes several of these to power anything significant, but you may be able to find use for one or a few for a lower-power device.