What is PV and how does it work?

What is PV?

The word "photovoltaic" (PV) groups the concepts of light and batteries ("photo" is Greek for "light" and "voltaic" is derived from the last name of the Italian physicist Alessandro Volta, who invented the chemical battery). The PV effect is what occurs when solar energy is directly converted into electricity. A PV cell is the hardware that transfers solar energy to electricity.

A group of PV cells (an array) linked to a battery (where the electricity is stored), electrical equipment or power lines, creates a PV power system. These systems do not have moving parts and are reliable, require minimal maintenance and do not have emissions or create pollution. PV systems can be adapted to any application, from powering a laptop to power plants that produce several megawatts.

How Does It Work?

Made from conductive materials, PV cells absorb incoming solar energy and separate the electrons from their atoms. The electrons then move through the material in a single direction (termed direct current or DC), carrying an electrical current.

Illustration: © Tobi McIntyre A PV module converts sunlight directly into electricity for your home or business.

This energy can then be used immediately or stored in batteries for later use. For optimal efficiency, excess power generated during the day is stored in batteries then used during the night or cloudy days.

For use in alternating current (AC) systems (electricity whose current and direction vary), the electricity generated by the PV cells can be converted from DC to AC and then fed into the municipal grid instead of batteries. During night or cloudy days, electricity can then be drawn from the grid. These systems are referred to as grid-tie or hybrid-grid systems.