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Solar power is energy which is obtained from the radiation of the Sun. Although it has been used for centuries, there has recently been a growth of interest in its use as an alternative to other energy sources because of increasing concern about pollution, global warming and rising energy costs and because of continuing advances in the technology to obtain convert solar radiation into usable forms. Energy from the Sun's radiation that reaches Earth is extremely abundant, and it is perhaps the greatest source of energy on Earth, except for the energy within the Earth's core. For example, each square kilometer of desert receives solar energy per year equivalent to roughly 1.5 million barrels of oil. Thus, using even just a tiny fraction of Earth's total land area to produce solar energy could provide far more energy than is currently consumed by humans. The main way in which solar power is produced at present is by using thin silicon panels that convert it directly into electricity. These are still costly to produce in large sizes and their sunlight-to-electricity conversion efficiency is still low. However, great progress has been made in recent years, and such panels are now sufficiently inexpensive and efficient that they represent a viable alternative to conventional power sources, particularly in remote locations where it can be inconvenient and costly to obtain conventional power. Another promising way of utilizing solar energy is to have arrays of large mirrors which reflect the sunlight from a large area to a boiler, which produces steam which, in turn, drives turbines that are connected to electrical generators. This is becoming increasingly practical as a result of the rapid drop in the cost of microprocessors and other electronic components that are required to keep adjusting the positions of the mirrors in response to the movement of the Sun across the sky. Solar power is just one of several forms of alternative energy that are attracting increasing interest and are the focal points of research and development. Others include harnessing the energy in wind, waves, biomass, waste products and the core of the Earth (geothermal energy). However, all of these except for geothermal energy are derived ultimately from solar energy. Created November 1, 2006. |