Geoelectricity | Wikipedia audio article
Geothermal. Power, is power generated. By geothermal energy. Technologies. In use include, dry steam power stations. Flash, steam, power stations. And binary, cycle power stations. Geothermal. Electricity, generation. Is currently, used in 26, countries while. Geothermal. Heating is in use in 70, countries as, of 2015. Worldwide, geothermal. Power capacity. Amounts, to twelve point eight gigawatts. GW, of. Which, 28%, or. 3548. Megawatts. MW are. Installed, in the United States. International. Markets, grew at an average annual, rate of 5% over the three years to 2015. And global, geothermal. Power capacity. Is expected, to reach fourteen, point five to seventeen, point six gigawatts. By 2020. Based. On current geologic knowledge. And technology. The heah publicly. Discloses. The geothermal, energy, Association, haiya estimates. That only six point nine percent of, total global potential, has been tapped so far while, the IPCC. Reported, geothermal. Power potential, to be in the range of 35 gigawatts, to two terawatts. Countries. Generating. More than 15, percent of their electricity from geothermal sources, include. El Salvador, Kenya. The Philippines, Iceland. New Zealand, and Costa, Rica. Geothermal. Power is considered, to be a sustainable. Renewable source. Of energy because, the heat extraction, is small compared, with the Earth's heat content, the. Greenhouse, gas emissions of geothermal electric. Stations, are on average 45, grams, of carbon dioxide per kilowatt hour of electricity, or less, than five percent of that of conventional, coal-fired, plants. As a source, of renewable energy, for both power and heating, geothermal. Has the potential, to meet three to five percent of global demand, by 2050. With. Economic. Incentives. It is estimated that by 2100. It, will be possible to meet 10% of global demand. Topic. History. And development. In the, 20th century demand. For electricity, led to the consideration, of geothermal power as, a generating. Source Prince, Pierrot jinora, county, tested, the first geothermal, power generator. On the 4th of july 1904. In, larger ello Italy, it. Successfully. Lit four light bulbs later. In 1911. The, world's, first commercial, geothermal power, station was, built their. Experimental. Generators. Were built in Beppu Japan. And the geysers, California. In the 1920s. But Italy was the world's, only industrial. Producer, of geothermal electricity. Until, 1958. In. 1958. New, Zealand, became the second major industrial. Producer, of geothermal electricity. When, its wairakei, station, was commissioned. Why. Rocky was the first station, to use flash steam technology. Over. The past 60, years net, fluid, production, has been in excess of 2.5. Cubic, kilometres. Subsidy. And set Wairakei tauhara has been an issue in a number of formal, hearings related to environmental, consents. For expanded, development. Of the system as a source of renewable energy, in, 1960. Pacific. Gas and Electric, began operation. Of the first successful, geothermal. Electric, power station, in the United States, at The Geysers in California.
The. Original, turbine, lasted, for more than 30 years and produced 11, megawatts, net power the, binary, cycle power station, was first demonstrated, in. 1967. In the Soviet, Union and later introduced, to the United States in, 1981. Following. The 1970s. Energy crisis. And significant. Changes, in regulatory. Policies. This. Technology. Allows the use of much lower temperature. Resources, than were previously, recoverable, in. 2006. A binary, cycle, station. In Chena Hot Springs. Alaska. Came online producing. Electricity. From a record low fluid temperature, of 57, degrees Celsius. One 135. Degrees, Fahrenheit, geothermal. Electric, stations, have until recently, been built exclusively where. High-temperature, geothermal. Resources, are available near, the surface, the. Development. Of binary, cycle power plants, and improvements, in drilling and extraction, technology. May enable enhanced geothermal, systems. Over a much greater, geographical. Range. Demonstration. Projects, are operational. In landau Fowles germany. And salt, zoos for its France, while, an earlier effort, in Basel, Switzerland was. Shut down after, it triggered earthquakes. Other. Demonstration. Projects. Are under construction, in Australia. The United Kingdom. And the United States, of America, the thermal, efficiency, of geothermal electric. Stations, is low around, 7, to 10% because. Geothermal. Fluids are, at a low temperature compared. With steam from boilers. By. The laws of thermodynamics this. Low temperature limits. The efficiency of heat engines in, extracting, useful energy, during the generation, of electricity. Exhaust. Heat is wasted, unless it can be used directly and locally, for example, in greenhouses, timber. Mills and district. Heating, the. Efficiency. Of the system does not affect, operational. Costs, as it would for a coal or other fossil. Fuel plant but it does factor into the viability of the station, in. Order, to produce more energy than the pumps consume, electricity. Generation, requires, high temperature, geothermal. Fields, and specialized, heat cycles. Because. Geothermal. Power does, not rely, on variable. Sources of energy unlike. For example wind. Or solar its capacity. Factor, can be quite large up to 96, percent has, been demonstrated. However. The global, average capacity factor. Was, 74.5%. In. 2008. According to the IPCC.
Topic. Resources. The, Earth's heat content, as about 1 times. 1019. Terajoules. 2.8. Times. 1015. Terawatt-hours. This. Heat naturally. Flows to the surface, by conduction. At a rate of 40 4.2. Terawatts, and is replenished, by radioactive. Decay at, a rate of 30 terawatts. These. Power rates, are more than double humanity's, current energy consumption. From primary, sources but, most of this power as to diffuse, approximately. Zero point one with m2, on average, to be recoverable. The. Earth's crust effectively. Acts as a thick insulating. Blanket, which must be pierced, by fluid conduits, of magma, water or other to release the heat underneath. Electricity. Generation, requires, high, temperature, resources. That can only come from deep underground. The. Heat must be carried, to the surface by fluid circulation. Either through, magma, conduits, hot springs. Hydrothermal. Circulation oil. Wells, drilled. Water wells or a combination, of, these, this. Circulation, sometimes. Exists, naturally, where the crust is thin magma, conduits, bring heat close to the surface and Hot Springs bring, the heat to the surface if no. Hot spring, is available. A well must be drilled into a hot aquifer. Away. From tectonic, plate boundaries, the geothermal, gradient as 25, to 30 degrees, Celsius, per kilometer km. Of depth in most of the world so, wells would have to be several, kilometers, deep to permit electricity. Generation. The. Quantity, and quality of recoverable, resources. Improves, with drilling depth and proximity, to tectonic, plate boundaries. In ground, that is hot but dry or where water pressure, is inadequate, injected. Fluid can stimulate production. Developers. Bore two holes into a candidate. Site and fracture, the rock between them with explosives. Or high-pressure water, then. They pump water or liquefied carbon dioxide. Down one borehole and it comes up the other borehole, as a gas, this. Approach, is called hot, dry rocked geothermal. Energy in, Europe or enhanced. Geothermal systems. In North America. Much. Greater potential, may be available, from this approach than from conventional, tapping, of natural, aquifers, estimates.
Of The electricity. Generating, potential, of geothermal energy, vary, from 35, to 2000, gigawatts, depending. On the scale of investments. This. Does not include non electric, heat recovered, by cogeneration. Geothermal. Heat pumps, and other direct, use a. 2006. Report by the massachusetts. Institute of, technology MIT. That. Included, the potential, of enhanced, geothermal systems. Estimated. That investing, 1 billion united, states dollars, in research and development over. 15, years would, allow the creation, of 100, gigawatts of electrical, generating, capacity by. 2050. In the United States alone, the. MIT, report, estimated. That over 200, times 109. Terajoules. 200. ZJ. 5.6. Times, 107. Terawatt hours would be extractable. With the potential, to increase this, to over 2,000. ZJ with, technology. Improvements. Sufficient. To provide all the world's present, energy needs for several millennia, at present, geothermal, wells are rarely more than three kilometres. 1.9. Miles deep. Upper. Estimates, of geothermal resources. Assume, Wells as deep as 10 kilometres. 6.2. Miles. Drilling. Near this depth is now possible in the petroleum, industry although. It is an expensive, process. The, deepest, research, well in the world the Kola super-deep borehole. KSD, b3, is twelve point two six one kilometers. Seven, point six one nine miles deep. This. Record, has recently been, imitated. By commercial, oil wells such, as ex and z12 well in the Chivo field Sakhalin. Wells, drilled to depths greater than four kilometers, 2.5. Miles generally. Incurred drilling, costs, in the tens of millions of dollars, the. Technological. Challenges, are to drill wide bores at low cost and to break larger, volumes, of rock. Geothermal. Power is considered, to be sustainable, because, the heat extraction, is small compared, to the Earth's heat content but, extraction. Must still be monitored to avoid local depletion. Although. Geothermal. Sites are capable, of providing heat, for many decades, individual. Wells may cool down or run out of water, the. Three oldest, sites at larderello, y rocky, and the geysers, have all reduced production, from their peaks it. Is, not clear, whether these stations, extracted. Energy faster. Than it was replenished from greater depths, or whether the aquifers, supplying, them are being depleted if. Production. Is reduced and, water is reinjected, these wells could theoretically recover. Their full potential. Such. Mitigation. Strategies, have already been implemented, at some sites the. Long-term, sustainability. Of geothermal energy, has, been demonstrated, at the larderello, field, in Italy since 1913. At the Y rocky, field in New Zealand since, 1958. And at The Geysers field, in California. Since, 1960. Topic. Power, station. Types. Geothermal. Power stations. Are similar, to other steam, turbine, thermal, power stations. In that heat from a fuel source in geothermal, case, the, Earth's core, is used to heat water or another working, fluid, the. Working, fluid is then used to turn a turbine, of a generator, thereby, producing electricity. The. Fluid, is then cooled and returned to the heat source. Topic. Dry. Steam, power stations. Dry. Steam stations, are the simplest, and oldest design, this. Type of power station. Is not found very often, because, it requires a resource, that produces. Dry steam but as the most efficient, with the simplest, facilities. In these. Sites there may be liquid, water present, in the reservoir, but no water is produced to the surface, only steam. Dry. Steam power directly. Uses geothermal. Steam of, 150. Degrees Celsius. Or greater to turn turbines, as, the. Turbine, rotates, it powers, a generator which. Then produces, electricity. And adds to the power field. Then. The steam is emitted to a condenser, here. The steam turns back into a liquid which then cools the water.
After. The water is cooled it flows down a pipe that conducts the condensate, back into deep wells where, it can be reheated, and produced, again, at the. Geysers in California. After the first 30 years of power production, the steam supply had, depleted, and generation. Was substantially. Reduced. To. Restore, some of the former capacity. Supplemental. Water injection. Was developed, during the 1990s. And 2000s. Including, utilization. Of effluent from nearby municipal. Sewage treatment, facilities. Topic. Flash. Steam, power stations. Flash steam, stations, pull deep high-pressure. Hot water into lower pressure, tanks, and use the resulting, fleshed steam, to drive turbines. They. Require, fluid, temperatures, of at least 180. Degrees, Celsius, usually. More, this. Is the most common, type of station, in operation. Today flash. Steam plants, use geothermal reservoirs. Of water with, temperatures. Greater than, 360. Degrees Fahrenheit. 182. Degrees Celsius. The. Hot water flows, up through wells, in the ground under its own pressure as, it. Flows upward, the pressure decreases, and some of the hot water boils, into steam, the. Steam is then separated from the water and used to power a turbine, generator. Any. Leftover. Water and condensed, steam may be injected, back into the reservoir making. This a potentially. Sustainable. Resource. Topic. Binary. Cycle power stations. Binary. Cycle power stations. Are the most recent, development. And can accept fluid, temperatures, as low as 57. Degrees, Celsius. The. Moderately, hot geothermal. Water is passed by a secondary, fluid, with a much lower boiling point than water, this. Causes the secondary. Fluid, to flash vapor ice which then drives the turbines. This. Is the most common, type of geothermal. Electricity, station. Being constructed. Today, both. Organic. Rankine, and Colinas cycles, are used the. Thermal, efficiency, of this type of station is typically, about 10 to 13, percent. Topic. Worldwide. Production. The, international, geothermal. Association. Iga, has, reported, that. 10715. Megawatts, MW of. Geothermal power. In 24, countries is, online which. Is expected, to generate. 67,000. 246. Gigawatt. Hours of electricity, in, 2010. This. Represents. A 20%. Increase in geothermal. Power online, capacity. Since 2005. Iga. Projected. This would grow to eighteen, thousand, five hundred megawatts. By 2015. Due to the large number of projects. That were under consideration, often. In areas previously assumed. To have little exploitable. Resource in, 2010. The United States led the world in geothermal, electricity, production, with three thousand eighty six megawatts of installed capacity from. Seventy-seven. Power stations. The largest, group of geothermal power plants. In the world is located at, the geysers a geothermal. Field in California. The. Philippines, follows, the u.s. as the second, highest producer. Of geothermal power, in, the world with. 1,900. For megawatts, of capacity online. Geothermal. Power makes, up approximately. 27%. Of the country's, electricity, generation. Al Gore, said in the climate, project, asia-pacific. Summit that Indonesia, could become a superpower, country, in electricity, production, from geothermal energy. India. Has announced a plan to develop the country's, first geothermal, power, facility.
In Chattisgarh Canada. Is the only major country on the Pacific, Ring of Fire which, has not yet developed geothermal. Power, the. Region, of greatest potential, as the Canadian, Cordillera stretching. From British Columbia to, the Yukon, where, estimates, of generating, output have ranged, from. 1,550. Megawatts, to 5,000. Megawatts. Topic. Utility-grade. Stations. The, largest, group of geothermal power, plants, in the world is located at, the geysers a geothermal, field, in California. United, States as. Of. 2004. Five, countries El Salvador. Kenya. The Philippines, Iceland. And Costa, Rica generate, more than 15 percent of their electricity from, geothermal. Sources, geothermal. Electricity, is, generated in. The 24, countries listed, in the table below. During. 2005. Contracts. Were placed for an additional, 500, megawatts, of electrical, capacity. In the United States, while, there were also stations. Under construction. In 11, other countries. Enhanced. Geothermal systems. That are several kilometers, in depth are operational. In France and Germany and are being developed or evaluated. In at least four other countries. Topic. Environmental. Impact. Fluids. Drawn from the deep earth carry, a mixture, of gases, notably, carbon, dioxide. Co2. Hydrogen. Sulfide, h2s. Methane. Ch4. Ammonia. Nh3, and. Radon, RN, if, released. These, pollutants contribute. To global warming acid. Rain radiation. And noxious, smells existing. Geothermal, electric, stations, that fall within the fiftieth percentile. Of all total life cycle, emissions studies. Reviewed by the IPCC. Produce. On average 45. Kilograms of, co2, equivalent. Emissions per, megawatt, hour of generated. Electricity, kilograms. Co2, equ, per megawatt, hour, for. Comparison. A coal-fired, power, plant, emits, 1001. Kilograms, of co2 per, megawatt. Hour when, not coupled, with carbon, capture and storage. CCS. Stations, that experience. High levels of, acids, and volatile, chemicals, are usually, equipped with emission, control, systems, to reduce the exhaust. Geothermal. Stations, could theoretically inject. These gases, back into the earth as a form, of carbon capture, and storage. In addition. To dissolved, gases, hot water from geothermal, sources may, hold in solution, trace amounts, of toxic, chemicals such, as mercury, arsenic. Boron, antimony. And salt. These. Chemicals. Come out of solution as the water cools and can cause environmental, damage, if, released. The. Modern practice, of injecting, geothermal. Fluids back, into the earth to stimulate. Production, has the side benefit, of reducing, this environmental. Risk. Station. Construction can, adversely affect land, stability. Subsidence. Has occurred, in the Y rocky, field in New Zealand, enhanced.
Geothermal Systems. Can trigger earthquakes due. To water injection, the. Project, in Basel, Switzerland was. Suspended, because more than 10,000. Seismic, events, measuring, up to 3.4. On the Richter scale occurred, over the first six days of water injection. The. Risk of geothermal, drilling leading, to uplift, has been experienced. In stofan, IM breisgau. Geothermal. Has minimal, land and freshwater, requirements. Geothermal. Stations, use 404. Square meters per gigawatt. Hour vs.. 3632. And. 1335. Square, meters for coal facilities. And wind farms respectively. They. Use 20, litres of fresh water per megawatt, hour versus, over 1,000. Liters per megawatt, hour for, nuclear, coal, or oil. Geothermal. Power stations. Can also disrupt, the natural cycles, of geysers. For. Example, the Bayeux wahwee Nevada geysers, which were uncapped, geothermal. Wells stopped, erupting due, to the development. Of the dual flash station. Topic. Economics. Geothermal. Power requires. No fuel, it is therefore immune to fuel cost fluctuations. However. Capital. Costs, tend to be high drilling. Accounts for over half the costs, and exploration. Of deep resources, entails. Significant. Risks. A, typical. Well doublet, in Nevada can support, 4.5. Megawatts, MW of. Electricity. Generation. And costs, about ten million dollars, to drill with a twenty percent failure, rate. In. Total. Electrical. Station, construction and, well drilling, costs, about two - five million euros, per megawatt of electrical. Capacity. While the levelized, energy, cost is. 0.04, -, ten cents per kilowatt, hour. Enhanced. Geothermal systems. Tend to be on the high side of these ranges, with capital, costs, above four million dollars, per megawatt, and levelized, costs, above. 0.05. Four dollars, per kilowatt. Hour in. 2007. Geothermal. Power is highly, scalable a small, power station, can supply, a rural village though. Initial, capital, costs, can be high the most developed geothermal. Field as the geysers, in California. In. 2008. This, field supported, 15, stations all owned, by Calpine, with a total, generating, capacity of. 725. Megawatts. Topic. See, also. Enhanced. Geothermal system. Geothermal. Heating. Hot. Dry rocked geothermal. Energy. Iceland. Deep drilling, project. List. Of renewable, energy, topics, by country.