If you have more than a passing interest in solar energy and are thinking of investing in a home solar panel array, then you probably have a vague idea of how solar panels generate electricity. When I first began looking into “going solar”, my concept of how these systems worked was basically this: sun shines on a solar panel, causes some sort of reaction within the materials of which the panel is made, and, voila, electricity results. Exactly how sunshine goes in and electricity comes out is a bit more complicated, however. A little bit of research will give you a pretty good understanding of how a solar electric panel works, and it’s pretty interesting stuff.
Solar Panels and Electricity Generation
The alternative name for solar panels is photovoltaic, which literally means “light electricity.” The idea that sunshine could be converted into electrical power was first noted by a French scientist named Alexandre Edmond Becquerel in 1839. Becquerel’s research led to simple photovoltaics that used selenium to produce electricity; not until the 1950s did silicon take selenium’s place as a superior electrical conductor. This new semiconductor material needed a little help to become an exceptional conductor of electricity, though, so researchers added other elements, such as phosphorus or boron. This process, called doping, greatly increases the silicon’s ability to create an electric current.
Each solar panel is actually made of individual photovoltaic (PV) cells, each of which is a tiny power generating plant. Hundreds of these cells are then made into a module, groups of which are in turn attached to a panel. A panel’s wattage is derived as a function of each cell’s electricity production and its voltage. How do the cells make electricity? Typically, each cell has two layers, both of which contain silicon. The top layer is doped with phosphorus, whereas the bottom one is doped with boron. This essentially sets up a situation whereby the bonding of silicon with each of these materials creates an electrical charge. The top layer generates a positive charge, while the bottom layer is negatively charged. The no man’s land in between these layers is called the P-N junction, where electron movement creates an electric field which keeps electrons moving from the P layer to the N layer, even though they would much prefer to move in the opposite direction.
Sunlight is the ingredient that gets all these electrons jumping around in the first place. As electrons move and are channeled into the appropriate direction, electrical wiring within the cell supplies the circuitry necessary for the generation of electrical power. Electrical Panel