The most useful way of harnessing solar energy is by directly converting it into DC electricity by means of solar photo-voltaic cells.
Photovoltaic comes from the words photo, meaning light, and volt, a measurement of electricity.
Photovoltaic cells are also called PV cells or solar cells for short.
The first practical PV cell was developed by Bell Telephone researchers.
At first, PV cells were used primarily in space to power U.S. space satellites. Now PV cells are common in many different applications.
Solar-powered toys, calculators, and many lighted roadside signs all use solar cells to convert sunlight into electricity.