Solar cells are most commonly made from silicon, the same material used to make computer chips. Silicon is one of the Earth’s most common elements, and is a major component of sand and many kinds of rocks. A solar cell is built like a sandwich, with two layers of silicon separated by a thin layer of insulating material. All three layers work together to convert sunlight into electricity. When sunlight falls onto the solar cell, it produces a small electric charge. Like a battery, the charge is positive on one side of the cell, and negative on.
