Photovoltaic energy

The sun's energy can also be made directly into electricity using photovoltaic (PV) cells, sometimes called solar cells. PV cells make electricity without moving, making noise or polluting. They are used in calculators and watches. They also provide power to satellites, electric lights and small electrical appliances such as radios. PV cells are even being used to provide electricity for homes, villages and businesses. Some electric utility companies are building PV systems into their power supply networks Although the PV cells used in calculators and watches are tiny--less than a half inch (1.2 centimeters) in diameter--PV cells for larger power systems are about 4 inches (10 centimeters) in diameter. When more power is needed, PV cells can be wired together to form a module. A module of about 40 cells is often enough to power a small light bulb. For more power, PV modules are wired together into an array. PV arrays can produce enough power to meet the electrical needs of your house--or for even larger uses.

Today, PV systems are mostly used for water pumping, highway lighting, weather stations and other electrical systems located away from power lines. For example, if you had a cabin on a mountain top, a PV system would allow you to read some of your favorite books before you went to sleep!

Because PV systems can be expensive, they are not used in areas that have electricity nearby. But if someone needs electricity in a remote place, PV can be quite economical. Another aspect of PV power is "intermittence," which means that if the sun isn't shining, the system can't make electricity. Because PV systems only produce electricity when the sun is shining, these remote systems need batteries to store the electricity.

See Solar Cell Animation in Video Section.

Renewable Energy Sources
What Is Renewable Energy?
Solar Energy
Photovoltaic Energy




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