How Do Solar Cells Work?

solar-cells-work Credit: Jon Olav Eikenes/CC-BY-2.0

Solar cells work by collecting sunlight and converting it to usable energy. This energy can be used onsite or transported short distances to the local power grid. A typical modern solar cell consists of a transparent protective outer layer, a dark layer to absorb photons and a network of support systems underneath to improve the cell's operational efficiency.

The transparent outer layer of a photocell is usually made from glass or durable synthetics. It is essential that the covering remains optically transparent to protect from losing photons before they reach the absorptive layer. The absorptive layer is the dark panel inside of the cell. Silicon is key to its operation. Silicon atoms naturally align to create an electrical gradient that herds electrons along in a common direction. This current is the electrical flow out of the cell that is taken up by transmission wires and carried to either a machine, for immediate use, or to a battery for storage.

The underlayer of a photocell consists of the cooling and structural supports that are necessary to keep the cell in operation. Many large photocells have motors mounted underneath that rotate them to face the sun continuously. This greatly increases the number of photons that can be captured in a single period of sunlight. It also permits each cell to generate more electricity.