How Solar Works

What Is A Solar Electric Or Photovoltaic System?

Photovoltaic (PV) systems convert sunlight directly to electricity. They work any time the sun is shining, but more electricity is produced when the sunlight is more intense and strikes the PV modules directly (as when rays of sunlight are perpendicular to the PV modules). Unlike solar thermal systems for heating water, PV does not use the sun's heat to make electricity. Instead, electrons freed by the interaction of sunlight with semiconductor materials in the PV cells are captured in an electric current.

PV allows you to produce electricity – without noise or air pollution – from a clean, renewable resource. A PV system never runs out of fuel, and it won't increase U.S. oil imports. Many PV system components are manufactured right here in the United States. These characteristics could make PV technology the U.S. energy source of choice for the 21st century.

The basic building block of PV technology is the solar "cell". Multiple PV cells are connected to form a PV "module", the smallest PV component sold commercially. Modules range in power output from about 10 watts to 300 watts. A PV system connected or "tied" to the utility grid has these components:

One or more PV modules, which are connected to an inverter.
The inverter, which converts the system's direct-current (DC) electricity to alternating current (AC).
Batteries (optional) to provide energy storage or backup power in case of a power interruption or outage on the grid.
AC electricity is compatible with the utility grid. It powers our lights, appliances, computers, and televisions.