Energy Sources to Supply Energy Needs

Solar Energy

• The transformation of solar power to energy occurs through a process called autotrophism, which employs sunlight to produce electricity for commercial, residential and institutional structures. Passive solar technology uses the sun's energy to provide heat for homes and businesses. Concentrated solar devices capture solar energy to fuel huge power plants. Solar water heating systems cool and heat industrial and commercial structures. Solar photovoltaic equipment transmutes solar energy into electricity in homes and commercial buildings.

Wind Power

• According to the U.S. Energy Administration, wind turbines in this country generated about 52 billion-kilowatt hours or 1.3 percent of electricity power in 2008. This small amount of electricity provided enough power for 4.6 million homes. Industrial-size wind turbines reach 200 or more feet above the ground. Wind energy works by rotors or blades at the top of a tower positioned to face the direction of the wind. The blades pull in kinetic energy, created by the wind's motion, and power a generator, which produces electricity. An anemometer fastened to the turbine measures the wind's speed and force. A yaw motor rotates the turbine's blades in the direction of the wind. It takes an eight mile an hour wind, for at least 18 hours a day, to generate electricity from this source.

Biomass Fuel

• Manure, branches, perennial plants, grasses, fast-growing trees and other natural material make very efficient environmentally friendly fuels. Numerous manufacturing processes, including lumber, plywood, paper and cotton result in the production of byproducts such as bark, sawdust and black liquor. This biomass produces clean energy. One method of extracting the product to create fuel involves the creation of a chemical reaction called photosynthesis, which produces sugar from plant biomasses and converts the sugar into ethanol. The process does not contribute to the greenhouse effect because it uses the same amount of carbon dioxide as it takes from the environment to make the sugar.

Geothermal

• As heat flows from the earth's core, where it exceeds 9,000 degrees Fahrenheit (F), the temperature moderates to between 50 and 60 degrees F for water only a few feet below the surface. Locations in the United States and around the globe use shallow ground water as sources of geothermal energy. The Geothermal Energy Association reports that in 2007 the U.S. generated about 14,885 gigawatt-hours of electricity. This equates to about four percent of the total renewable energy sources produced in the country. In addition, it constitutes 30 percent of the total world output--more than any other country.

  Geothermal energy works by a system of heating pumps that circulate water or other liquids through buried pipes. When used for heat, the system distributes the earth's heat through the liquid and then to the structure. Heat pumps cool buildings by pulling hot air from the structures and feeding it into the earth.