Solar energy forms through photovoltaic cells that convert sunlight into electricity. Solar batteries generate electric power from solar cells composed of a semiconductor material, usually silicon. Solar power is used to power items as small as calculators and wrist watches to complex equipment, such as artificial satellites and spaceships.
Photovoltaic cells are used in solar panels to convert sunlight into electric power. When sunlight enters the cells, it causes the electrons to move around and create electrical energy in the external circuits. The three basic types of solar cells made from silicon are single-crystal, polycrystalline and amorphous. Single-crystal cells are the most efficient cells but are more expensive and energy-intensive to produce. Estimates suggest that single-crystal cells account for 29 percent of the global market for photovoltaic cells.
Solar energy is a renewable form of energy because it comes from a source that is naturally replenished: the sun. Furthermore, solar energy does not pollute the air and water, which makes it a suitable alternative to traditional fossil fuels. According to the Union of Concerned Scientists, solar energy is "poised to play a prominent role in our energy future." Although the future of solar energy is promising, the main challenge lies in harnessing the power of the sun in a more efficient and cost-effective way.