How do solar panels work?
Solar panels turn sunlight into electricity using photovoltaic cells, usually made of silicon. When light hits the cells, it knocks electrons loose, creating an electric current.
Each solar panel contains many cells made of thin layers of silicon treated with other elements to create an electric field. When particles of light, called photons, strike the cell, they give energy to electrons, freeing them from their atoms. The electric field pushes these electrons in one direction, creating direct current electricity.
Most homes and the power grid use alternating current, so a device called an inverter converts the electricity from the panels. Panels work best in direct sunlight but still produce some power on cloudy days. Typical modern panels convert about 20 to 23 percent of sunlight into electricity.
Growing fast
The price of solar panels has dropped by about 90 percent since 2010, making solar one of the fastest-growing energy sources in the world. China manufactures most of the world's solar panels and installs more solar power than any other country.
Did You Know?
The photovoltaic effect was discovered in 1839 by French physicist Edmond Becquerel, who was just 19 at the time.