Geothermal District Heating
The country of Iceland is a leader in the harnessing and use of geothermal energy, both by providing clean electricity to its citizens and industry as well as heat and hot water for domestic consumption and industrial and municipal uses.
Besides the electricity generation, geothermal energy has multiple direct use applications, such as space heating for homes and businesses, thermal spas and swimming pools, greenhouse heating, snow melting, industrial use like fish farming, wood/fish drying and more.
Cogeneration of geothermal heat and electrical energy started in Iceland with the HS Orka's Svartsengi Combined Heat & Power (CHP) plant, which produces 75 MW of power and 150 MW of thermal power to the geothermal district heating system of the municipalities in the Reykjanes peninsula, as well as providing the geothermal water to the world renown Blue Lagoon Spa. The Nesjavellir CHP plant is providing 120 MW of electricity and 300 MW of heat for Reykjavik Energy's district heating system.
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Geothermal District Heating Expertise
Geothermal energy has been utilized for space heating in Iceland since the 1930s. Icelandic utilities have more than 70 years of experience in district heating systems and operate the world’s largest, most modern geothermal CHP system, providing nearly 90% of the population with space heating from geothermal energy alone, eliminating the burning of fossil fuel. A great example of utilizing a geothermal resource for different applications is HS Orka’s Blue Lagoon, which attracts over 400,000 visitors annually. Located next to the Svartsengi CHP plant, the spa has significant environmental benefits and greatly improves the financial viability of the plant. Orkuveita Reykjavikur (Reykjavik Energy), owns and operates the largest geothermal district heating system in the world with installed capacity over 800 MWth. A part of this DH system is the Nesjavellir CHP plant, with the new Hellisheidi CHP plant adding 400 MWth, once completed in 2012.
Enex Kina, in a joint venture with local Chinese partners, is constructing a geothermal district heating system in the city of Xianyang, China, which is to become the world's largest geothermal district heating system in 2012-2015. Enex's subsidiary in the United States is to build a geothermal district heating system in California. Previous consulting work to the World Bank include the restructuring of the Geotermia Podhalanska geothermal power plant in Zakopane, Poland and contractor work on the heating system in the Slovakian city of Galanta. Other Slovakian projects are in progress in cooperation with local municipalities.
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A competitive source of energy
The primary purpose of a geothermal district heating system is to provide an economic supply of energy suitable for space heating. The district heating system produces a long term stable source of energy, not dramatically affected by events which produce changes in petroleum prices. Established geothermal heating districts, some with decades of operation, have proven this can be an economically competitive and reliable method of space heating, utilizing simple, proven technology at a low operational cost.
A reliable source of energy
Compared to the conventional fossil fuels, a geothermal reservoir provides a clean source of energy. Developing a geothermal district heating system contributes to the sustainable management of natural resources and to improve quality of life by reducing the emission of gases and particulates contributing to local and global air-pollution.
A clean source of energy
The burning of oil and gas for energy produces air pollution. Geothermal energy can replace oil and gas burning for space heating, and as a result, air quality will improve.
One of the most significant environmental benefits of geothermal energy is cleaner air, which translates into fewer respiratory health problems due to the zero emission of greenhouse gases into the atmosphere.
In geothermal district heating systems a closed piping system is usually employed, where the geothermal fluid is contained within pipes from production through utilization and subsurface disposal by injection back into the reservoir. This design ensures zero emission and minimal environmental impact, i.e no atmospheric discharge occurs because heat exchangers extract thermal energy from the completely contained geothermal heating system.
Listed below are benefits which a geothermal district heating system provide:
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A competitive source of energy
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A reliable source of energy
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A clean source of energy
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Improved air quality
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Stable energy prices
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Improved commercial competitive advantage
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Increased real estate value in areas with geothermal heating
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Positive public image
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Multiple usage possibilities
Photos: Geothermally heated greenhouses for agriculture
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STRATEGIC OPPORTUNITY
Because geothermal electrical and thermal generation has no fuel cost, it is a natural, and cost effective, alternative to fossil fuel powered generating systems.
With the recognition of the potential dangers of global warming, geothermal heat for electrical and district heating use is one of the most effective ways of combating greenhouse gases, now recognized as a major component of this phenomenon.