Photovoltaic (or PV) systems convert light energy into electricity. The term "photo" is a stem from the Greek "phos," which means "light." "Volt" is named for Alessandro Volta (1745-1827), a pioneer in the study of electricity. "Photo-voltaics," then, could literally mean "light-electricity." Most commonly known as "solar cells," PV systems are already an important part of our lives. The simplest systems power many of the small calculators and wrist watches we use every day. More complicated systems provide electricity for pumping water, powering communications equipment, and even lighting our homes and running our appliances. In a surprising number of cases, PV power is the cheapest form of electricity for performing these tasks.

Here, we describe the PV effect that allows various materials to produce electricity from sunlight; show how PV cells, modules, and arrays are made; explain why PV is the most logical power choice in many different cases; and provide real examples of how this science is improving the lives of people all over the world!

Hey, students and teachers! We've prepared a number of online and printable quizzes to help test your knowledge of PV. They're all in Learning About PV.