The photovoltaic process converts sunlight ? the most abundant energy source on the planet ? directly into electricity. The sun emits photons (light), which generate electricity when they strike a photovoltaic cell. In the same way, a photovoltaic cell, made from a semi-conducting material, is a device that converts light into electricity.
Solar cells are made two or more thin layers of semi conducting material, usually silicon (a special type of melted sand). The layers are given opposite charges ? one positive, one negative. When sunlight strikes the solar cell, electrons are knocked loose and move toward the treated front surface of the solar cell. This creates an electron imbalance between the front and back of the cell and causes electricity to flow ? the greater the intensity of light, the greater the flow of electricity.