Geothermal Sources

Geothermal Sources
By Debbie Pollitt, eHow Contributor
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Nearly 90 percent of Icelandic residents use geothermal energy for heat.
Geothermal energy is literally the natural heat of the Earth — earth (geo) heat (therme) — and a renewable resource that can be used to heat buildings and generate electricity. The heat is continuously produced deep within the Earth’s core, will never run out and can be redeemed as steam or hot water. U.S. geothermal projects rose by 12 percent in 2010 and, as of 2011, nine states produce geothermal power.
Billions of years ago when the Earth was forming, large amounts of energy were caught in the middle of the planet, bonding molecules of iron and nickel together to make the Earth’s core. The core is about 4,000 miles beneath the surface on top of which are two more layers — the mantle and the crust. High temperatures are continuously produced and the deeper the layer within the Earth, the hotter the heat. Geothermal energy comes from the intense heat and is caused by the slow decay of radioactive particles, a process that happens naturally in all rocks.
Hot Spots
The Earth’s crust keeps the heat of the mantle beneath the surface but when the heat becomes so intense that it breaks through the crust, it creates patches of geothermal energy known as hot spots. Hot spots can be in the form of volcanoes or geysers. Yellowstone National Park, for example, is home to many geysers, the most famous of which is Old Faithful. Cracks and openings in the crust create ventilation points ensuring that the mantle is able to keep the Earth’s surface continuously heated. This kind of geothermal energy emerges less explosively in the form of steam, creating springs and wells of heated water.
Geothermal energy is potentially everywhere but finding it is easier said than done. Volcanoes, springs and geysers are useful indicators of geothermal reservoirs and scientists may find clues by analyzing local soil and water sources but otherwise the most reliable way to locate them is to dig deep and drill. The world’s hottest geothermal area is the Pacific Ocean’s “Ring of Fire” while America, New Zealand, Iceland and Indonesia are also countries rich in geothermal sources. U.S. geothermal systems include the Geyser’s region of Northern California, Southern California’s Imperial Valley and the Yellowstone areas of Idaho, Montana and Wyoming. Hawaii, Arkansas and Texas also have significant geothermal activity.
Advantages of Geothermal Energy
It’s a very clean source of energy as nothing has to be burnt to produce the steam to turn the turbines. Using geothermal energy produces fewer greenhouse gas emissions than other energy sources. It is available around the clock, every day of the year and is capable of reducing America’s reliance on foreign oil imports. Geothermal plants can produce cheap electricity and although the initial construction and start-up costs are high, the long-term costs are low compared to conventional power plants. There are no transportation costs and the supply is reliable, predictable and stable.
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