The clean and renewable source of energy derived directly from sun light. A wide range of power technologies exist which can make use of the solar energy reaching Earth as in the following examples:
Sunlight hits a photovoltaic cell (also called a photoelectric cell) creating electricity. Sunlight hits the dark absorber surface of a solar thermal collector and the surface warms. The heat energy is carried away by a fluid circuit. Sunlight strikes a solar sail on a space craft and is converted directly into a force on the sail which causes motion of the craft. Sunlight strikes a light mill and causes the vanes to rotate, although little practical application has yet been found for this effect. Sunlight is focused on an externally mounted fibre optic cable which conducts sunlight into building interiors to supplement lighting. Most solar energy used today is harnessed as heat or electricity. Technologies that enable the use of solar energy may be grouped as below:
Solar design is the use of architectural features to replace the use of grid electricity and fossil fuels with the use of solar energy and decrease the energy needed in a home or building with insulation and efficient lighting and appliances, Solar heating systems are generally composed of solar thermal collectors, a fluid system to move the heat from the collector to its point of usage, and a reservoir to stock the heat for subsequent use. Solar cells, also referred to as photovoltaic cells, are devices or banks of devices that use the photovoltaic effect of semiconductors to generate electricity directly from sunlight. Additional Resources:
Got Sun? Go Solar: Get Free Renewable Energy to Power Your Grid-Tied Home
Consumer Guide to Solar Energy, 3rd Edition