How do solar panels generate electricity?

Solar panels generate electricity through the photovoltaic effect. Each panel is made of many cells, usually of silicon, specially treated so that one layer has a slight positive charge and another a slight negative charge, creating an electric field between them. When particles of light called photons strike the silicon, they knock electrons loose from their atoms. The built-in electric field pushes these free electrons to flow in one direction, producing a direct electric current. An inverter then converts this into the alternating current used in homes and the grid. Solar panels produce no emissions while operating and can generate power for around 25 to 30 years.