Renewable Sources of Energy and ElectricityRenewables
Energy from the sun can be used in several ways. For example, solar energy can be used to heat homes by taking advantage of south-facing windows (solar heating), and can be used to heat water (solar water heating) with flat plate solar collectors. Energy from the sun can also be used to generate electricity. Sunlight can be used to heat water to create steam, which powers a turbine and generates electricity (solar thermal electric power). Photovoltaic (PV) cells, or solar cells (much like those on a solar calculator), convert sunlight directly into electricity. Thousands and thousands of these cells can be joined together to form a photovoltaic system that can be incorporated into an electric utility's supply network. ....
Photovoltaic systems are ideal for remote or rural villages, and stand alone sites or residences. In early July 1998, photovoltaics became the fastest-growing energy source, as world-wide production increased 40% in the past year. Converting solar energy into electricity suffers from the constraint that electricity cannot be produced when the sun isn't shining.....
Wind can also be used to generate electricity and is the second-fastest growing energy source. Blades on a wind turbine turn when the wind blows, and drive a generator which produces electricity. ...... http://www.cleanerandgreener.org/schools/energysources.htm |
