
A History of Geothermal Power
The history of geothermal energy use traces back tens of thousands of years around the globe. In times pre-dating modern western civilization, indigenous peoples used hot water from springs for cooking, cleaning, and bathing. These springs served as a source of warmth and their minerals as a source of healing. Archeological evidence shows that the first human use of geothermal resources in North America occurred more than 10,000 years ago with the settlement of Paleo-Indians around hot springs.
Modern use of geothermal energy is characterized by increasingly more organized commercial and industrial ventures from spas and resorts in the early 1800s to the eventual development of electricity production and geothermal heat pumps. The first known commercial use of geothermal energy in the United States occurred in Hot Springs, Arkansas, where, in 1830, Asa Thompson charged one dollar each for the use of three spring-fed baths in a wooden tub. Within the next twenty years, more resorts and spas of increasing size would grow up around such springs.
In 1892, the world's first district heating came online in Boise, Idaho, eventually growing to serve 200 homes and 40 downtown businesses. Although this system was unique for 70 years, there are now 17 geothermal district heating systems in the United States and dozens more around the world. In Iceland, the entire capital city of Reykjavik is powered by the geothermal energy from the North Atlantic Oceanic Ridge below the island.
In the early 1900s, the first instance of geothermal electric power emerged. In Italy, Prince Piero Ginori Conti invented the first geothermal power plant in 1904 at the Larderello dry steam field and it is still in operation today. The first geothermal electricity plants in the United States were operated in 1960 at The Geysers in Sonoma County, California. They produced 11 megawatts (MW) of net power and operated successfully for more than 30 years. Today, 69 generating facilities are in operation at 18 sites around the country.
Throughout the 1970s, government backing through legislation, grants, and the actions of agencies like the Department of Energy furthered research, development, and continued acceptance of geothermal electrical power into the electricity producing mainstream. Work in the 1970s laid the foundation for actualization of more advanced types of geothermal steam production in the 1980s from flash steam to binary vapor cycles. Net electrical output of these plants reached 50MW by the end of the decade. Progress continued in the 1990s as the Department of Energy increased its efforts to promote the use of geothermal energy for electricity generation as well as space and process heating. By the mid-90s, the DOE identified over 9000 thermal wells and springs and 271 communities connected to geothermal energy.
Modern non-electrical use of geothermal energy continues. For instance, beginning in the 1960?s the Maoris of New Zealand have used geothermal energy for cooking. France and many other European Union nations are using geothermally heated water to heat thousands of homes.
For more information about the history of geothermal energy, visit the following web sites.
A History of Geothermal Energy in the United States
A comprehensive timeline of geothermal energy in the United States, from the early 1800s until the year 2000, covering the opening of spas and resorts to research and development of cutting-edge advanced technology for electrical production in the late 20th century.
History of the utilization of geothermal sources of energy in Iceland
Brief review of early geothermal energy efforts in Iceland, especially focusing on the digging of Thvottalaugar (washing pools) around the capital city of Reykjavik.
History of Geothermal Energy
A down-to-earth overview of some ancient and modern examples of geothermal energy worldwide, with focus on pre-industrial usage.
REPP-CREST Geothermal History
A late 20th-Century timeline, in brief, of modern geothermal electricity and heat pumps in the United States. Covers major events, government agencies, and legislation between 1960 and 2000.
Geothermal Energy and Other Distinctive Energy Sources
Milestones in geothermal power intertwined with relevant historical instances in thermodynamics, engineering, drilling, and electrical power production. Short essay covering low tech to high tech uses, including a drilling and mining angle.
Modern Heating and Cooling for Historic Structures Slide Show Presentation
Flash slideshow of how small-scale geothermal power is helping preserve the historic integrity of landmark buildings while giving them the comfort and convenience of modern heating and cooling systems. One such project was the Trinity Church in Copley Square in Boston, Massachusetts.
What is GEOTHERMAL ENERGY ???
ReplyDeleteGeothermal energy is an alternative energy source, although it is not resourceful enough to replace more than a minor amount of the future's energy needs. Geothermal energy is obtained from the internal heat of the planet and can be used to generate steam to run a steam turbine. This in turn generates electricity, which is a very useful form of energy.
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The radius of the Earth is about 4000 miles, with an internal core temperature of about 4000 degrees celsius at the center. The mantle surrounds the outercore and is only about 45 miles below the surface, depending on location. The temperature at the mantle-surface crust boundary is about 375 degrees, celsius. (This is too deep to get to...as of today)
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So...what???
So, how does this help us? It turns out that if we drill down only three miles we can reach temperatures of 100 degrees, celsius, which is enough to boil water to run a steam-powered electric powerplant. Drilling three miles through the earth is possible, but not easy, so luckily there are easier routes to access this power source, known as geothermal hotspots.
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What's a Hotspot?
Geothermal hotspots are volcanic features which are found all around the world. Basically a hotspot is an area of reduced thickness in the mantle which transmits excess internal heat from the interior of the earth to the outer crust. These hotspots are well known for their unique effects on the surface, such as the volcanic islands of Hawaii, the mineral deposits and gyesers in Yellowstone National Park, or the hotsprings in Iceland. These geothermal hotspots can easily be used to generate electricity.
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How do Geothermal-Energy Systems Work?
Some systems pump hot-water into permeable sedimentary hospots found underground and then use the steam to generate electricity. Then the used steam is condensed and sent back down to the permeable sedimentary stream. Another system utilizes volcanic magma which is still partly molten at around 650 degrees, celsius, to boil water which would generate electricity. Also there is a system which uses hot dry rock, which is just hardened magma, but still is extremely hot. To recover this heat from these rocks, a system is used which circulates water through the rock and transfers the heat up to a steam generator. The first system listed here is not as useful as other methods because of the acidic nature of the fluids found under the ground. These acidities require a lot of maintenance and upkeep on the equipment, and this cost reduces the economic effectiveness of the system. Therefore, geothermal energy systems are more inefficient than other alternative energy sources because of the costs required in upkeep and the shortage of potential sites.
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For more information on geothermal energy