the Geothermie, or terrestrial heat, is the warmth stored in the upper (accessible) part of the earth's crust. It covers the energy, as far as it can be extracted and used, stored in the earth, and ranks among the regenerativ energies. It can both directlyare used, approximately for heating and cooling in the heating market, and for the production by electric current or in a force heat coupling. Geothermie designates both the engineering occupation with the terrestrial heat and its use, and the scientific investigation of the thermal situation of the earth body.

Geothermische Feldtests in Tibet
Geothermal field tests in Tibet
Geothermische Anlage in Kalifornien
geothermal plant in California

table of contents

origin of geothermal energy

Geothermie comes partially (estimated: 30-50 per cent) from the remainder warmth from the time of the earth emergence (Akkretion), on the other hand(estimated: 50-70 per cent) from radioactive decay processes, which produced warmth in the earth's crust for millions of years continuously and today to still produce. Completely near the surface portions from the sun exposure on the earth's surface and from the heat contact with air are added.

The temperature inside earth core amounts toaccording to different estimations 4500 °C to 6500 °C. 99 per cent of our planet are hotter than 1000 °C; 99 per cent of the remainder are still hotter than 100 °C. Nearly everywhere the soil in 1 kilometer of depth has a temperature of 35 °C to 40 °C(see also geothermal depth stage). Under special geological conditions - order for example in today's or earlier volcano - geothermal anomalies develop. Here the temperature can reach many hundred degrees Celsius.

Remainder warmth from the time of the earth emergence

the earth is before zirka 4,6 -4,7 billion years by Akkretion of subject developed. Here the material heats up, whereby kinetic energy (kinetic energy) is converted into warmth. This heat energy kept because of the small heat conductivity of the rocks and thus the small heat emission to space until today partially andcan be called remainder warmth from the time of the earth emergence.

Radioactive decay processes

this portion of the Geothermie goes on the natural decay of the long-lived radioactive isotopes existing in the earth body like e.g. Uranium -235 and U-238, thorium -232 and potassium -40 back. These elements are into those Crystal lattice of certain minerals built, for example into the feldspars and mica in granites. This concerns a natural form of the nuclear energy.

The achievement, which results from the radioactive decay, amounts to about 16 · 10 12 Watts. With a middle Erdradius of 6371 km the geothermal power density of the radioactive decay at the earth's surface about 0.032 Watts (32 mW) per square meter of earth's surface amounts to. This would constitute about half of the terrestischen heat flow.

Heat flow from the interior of the earth

the warmth becomes from deeper parts of the earth by thermal conduction, thusKonduktion, in addition, by convection into depths attainable for the use transports.

The terrestrial heat flow, those of the earth per square meter to space output, is about 0.063 Watt/m ² (63 mW/m ²) (heat flow density). This is a relatively small value and points already to itthat Geothermie is predominantly suitable for the decentralized use. In abnormal areas, as for instance volcanic areas, the heat flow can be larger around a multiple.

Because of the small heat flow density predominantly not the energy flowing from the interior of the earth becomes, but in the earth's crust with the Geothermienutzungstored energy used or diminished. A Geothermienutzung must be dimensioned in such a way that cooling down the earth body concerned progresses so slowly that in the utilization period of the plant the temperature drops only to an extent, which permits an economical enterprise of the plant.

Organization of the Geothermiequellen

Geothermie can as energy source for the production of warmth and river to be used. Here becomes between the use

  • of the Geothermie near the surface the direct use, usually heating and cooling, and
  • the deep Geothermie for direct use or also for generation of current differentiated.

Further becomes between high and low enthalpy- Stores differentiated. High enthalpy means that such stores place a high temperature ready.

Deep Geothermie

the more deeply one into the earth's crust bores, the more highly rises the temperature. On the average receives one per kilometer of depth a rise in temperature from 35 K to 40 K (geothermal depth stage). The geothermal depth stage is however regionally very different. Deviations from the standard are called heat anomalies. Interesting particularly are areas with clearly higher temperatures. Here the temperatures can amount to in small depth several hundred degrees. Such anomalies are frequently attached at volcanic activity. In thatGeothermie are considered it as hochenthalpe stores. They are used world-wide for generation of current.

High enthalpy stores

the world-wide generation of current from Geothermie one dominates by the use of high enthalpy stores. These are heat anomalies those with volcanic activity accompany. There several hundred degrees are hot fluids (water/steam) in smallerTo find deep one. Their occurrence correlates strongly with volcanos in the appropriate countries.

Country number of volcanos resources
MW e
the USA 133 23,000
Japan 100 20,000
Indonesia the 126 16,000
Philippines 53 6,000
Mexico 35 6,000
Iceland 33 5,800
New Zealand 19 3,650
Italy (Toskana) 3,700
(source:Literature/statistics, 5.)

Dependent on the pressure and temperature conditions high enthalpy stores can be water-dominated more steam or more. In former times steam became after the use into air to dismiss, which could lead to substantial sulfur smell (Italy, Larderello). Today the cooled down fluids are reinjiziert into stores(back pumped). Thus negative environmental effects are avoided and at the same time the productivity by maintaining a higher pressure level in stores is improved.

Niederenthalpie stores

in not-volcanic areas can be very different the temperatures in the underground. Usually are however, if for the use higher temperatures are used,deep drillings necessarily. For an economic generation of current temperatures over 100 are necessary °C. If these are present in a Aquifer , then can be promoted, cooled down and reinjiziert from this water. One speaks then of Hydrothermaler Geothermie. The rock is found, in that the high temperatures, if few became permeabel, so that from it no water can be promoted, then one can let circulate there on an artificial tear system water. One speaks of Petrothermaler Geothermie. A further possibility, with which however comparatively little energy is extracted, is a deep terrestrial heat probe, where the water only within the probe circulates (closed system).

With respect to the range of the deep Geothermie three kinds of the heat extraction from the underground are generally differentiated:

  • Hydrothermale of systems: in the underground existing Thermalwässer Petrothermale of systems circulate between two wells over existing natural groundwater leaders (
  • Aquifere),often also HDR - systems (H ot D ry R ock) mentioned: with hydraulic Stimulationsmassnahmen in the dry underground tears and gaps are produced, into which artificially brought in water between two deep wells circulates.
    The acceptance is actual to find at these temperatures and depths dry Gesteinsformationen,not correctly. For this reason also different other names for this procedure exist: and. A.Hot Wet skirt (HWR), Hot Fractured skirt (HFR) or Enhanced Geothermal system (EGS). A neutral designation is Petrothermale of systems.
  • Deep terrestrial heat probes: the heat distribution medium medium circulates in a closed cycle within a drilling in oneU-Rohr or a coaxial probe

of which of the which are applicable procedures is used, is on the geological conditions at the location, dependent on the necessary energy quantity and the demanded temperature level of the utilization of heat. At present in Germany almost exclusively hydrothermale systems are planned. HDR procedures are into thatPilot projects in bath Urach and in Soultz sous Forêts in the Elsass in testing. In SE Australia (Cooper Basin, new South Wales) a commercial project is in the course since 2001 (company Geodynamics Limited).

Hydrothermale of systems

for the hydrothermale Geothermie become in large depths naturally occurring Thermalwasservorräte, so-called hot water Aquifere(water-prominent layers) tapped. The hydrothermale power production is possible depending upon temperature as warmth or river.

Petrothermale of systems

of rocks in larger depth point a high temperature to (Hot Dry skirt). This energy can be used for the current and heat production. Around the warmth of these rocks use toocan, they must be flowed through by a heat distribution medium (water), which brings the energy afterwards to the surface.

The principle of the use of the Geothermie from hot close rock (HDR), see also “Petrothermale of systems”

the water heated up by the hot rock formations can for the supply of industrial steam andfor the supply by close and long-distance heating nets to be used. The production of river from hot steam is particularly interesting. For this the water heated up in the underground is used to propel a turbine. The closed cycle in the circulation system stands in such a way under pressure that simmering the pressed inWater is prevented and steam only at the turbine develops.

The hot rock existing in the depth is opened over drillings. Here there is at least a promotion and an injecting drilling, which are connected by a closed water circulation. At the beginning water with enormously high becomesPressure into the rock pressed (hydraulic Stimulation); thereby flow ways are broken open or expand existing and increased thus the permeability of the rock. This procedure is necessary, since otherwise the heat transfer surface and the constantness would be too small. In such a way created system from natural and artificial tears formsan underground, geothermal heat-transfer agent. By the injections injecting drilling is pressed water into the gap system, where this heats up circulated and. Subsequently, it is promoted by the second drilling, the production/promotion drilling, the surface.

Deep terrestrial heat probes

the deep terrestrial heat probe is a closed system toTerrestrial heat production. It consists of 2000 to 3000 m deep a drilling, in which a fluid circulates. Usually one includes thereby the fluid in a coaxial pipe: In the annular space of the drilling the cold heat distribution medium fluid flows, over downward afterwards in the thinner hung upRiser warms up again to ascend. Such terrestrial heat probes have the advantage in relation to open systems that no contact exists to the groundwater. They are possible at each location. Their withdrawal achievement depends apart from technical parameters on the mountain temperatures and the conductivenesses of the rock. Them become however only some hundredsKW amount to thus substantially smaller and its than with a comparable open system. This is because of the fact that the exchange surface with the mountains is very small, since it corresponds practically to the lateral surface of the drilling.

New deep terrestrial heat probes become to time (2005) in Aachen (university) and Arnsberg (leisure time swimming pool Wet) built.

Alternatively to the circulation of water (possible with additives) in the terrestrial heat probe also probes with direct evaporators (heat pipes or from the English Heatpipes) were suggested. As media either a liquid with an accordingly low boiling point can be used, or a mixturefor example from ammonia and water. A such probe can be operated also under pressure and then for example with carbon dioxide. Heatpipes can have a higher withdrawal achievement than conventional probes, since they can have the evaporation temperature of the medium on their entire length.

Geothermie near the surface

the temperatures thatAir vary with the season very strongly. Within the upper layers of the ground these temperatures do not become however and/or. only very strongly absorbed reconstructed. From mathematical view the temperature gradient of an absorbed harmonious oscillation follows. In 5 to 10 m depth corresponds in the soil the measuredTemperature practically the annual average temperature of the location (approx. 8 to 10 °C in Germany). (Chart)

of means terrestrial heat probes (vertical or diagonal drillings or horizontal and near the surface in the soil brought in systems), in addition, with ground-based concrete construction units the warmth is promoted to the surface. Usually heat pumps cometo the employment, in order to realize heating's applications for buildings. With terrestrial heat can be cooled in the summer in addition.

Geothermie from tunnels

the production of thermal energy from tunnels is called also Tunnelthermie. By the large, earthaffected surfaces this relatively recent technology places however a highNutzungspotenzial particularly in tunnels in the city.

Geothermie from mining industry plants

of mines and expenditure-promoted deposits of natural gas, which are shut down because of the exhaustion of the supplies, are conceivable projects for Tiefengeothermie. This applies reduced also to deep tunnels. The there formation water are depending upon depth of stores 60until 120 is °C hot, the drillings or pits often still available and could are after-used, in order to supply the warm stores water of a geothermal use.

Such plants for the production of the geothermal energy must be integrated in such a way into the mechanisms for the Verwahrung of the mine that those publiclylegally standardized safe-keeping goals, the shut down mine (§ 55 paragraph 2 federal mountain law and § 69 exp. To be kept drive-free 2 federal mountain law), be fulfilled also with the additional mechanisms.

Seasonal heat accumulators

Geothermie stands always, thus independently of the daily and season and also independently of the weatherfor the order. Optimally a plant will work even if it is used accordingly time-homogeneous. This is z. B. the case if in the winter one heats and one cools in the summer and those are about alike for this to necessary energy quantities. In the case of cooling in the summer arisesa heating up of the reservoir and thus its regeneration. This function is strengthened, if Geothermie with other plants z. B.Solarthermie is combined. Solarthermie predominantly makes warmth available in the summer, if she is used less. By combination with Geothermie this energy leaves itself inSummers into the underground heat accumulator feed and in the winter again call up. The losses are location dependent, but usually small.

Seasonal memory can be deeply implemented both near the surface, and. So-called high temperature memory (> 50 °C) is conceivable however only in larger depth. For example that orders Realm tag building over a such memory.

Use of terrestrial heat

the Geothermie is a on a long-term basis usable energy source. With the supplies, which are stored in our planet, in principle the world-wide power requirement could be covered for over 100,000 years.

During the use of the Geothermie one differentiates between Direct use, thus the use of the warmth and the use after transformation in river in a Geothermiekraftwerk. From the view of the optimization of efficiencies also here force heat couplings (KWK) are optimal. The problem are here the customers of the warmth. At each power station location do not becomecustomers for the warmth to find leave themselves. The demand for excluding KWK projects remains a dream.

Direct use

geothermal energy is used for over 10,000 years. Our ancestors used probably geothermally warmed up water for cooking, bathing and heating.

Type of use temperature
a cooking and evaporation, seawater desalination 120 °C
drying process of Zementplatten 110
drying process of organic material such as hay, vegetable, wool 100
air-drying of stick fish 90
space heating (classical) 80
cooling 70
animal breeding 60
mushroom breed, Balneologie, using warm water 50
cabin ground heating system of 40
swimming pools, ice-free attitude, biological dismantling, fermentation 30
pisciculture 20
natural cooling< 10 °C
Lindal diagram

Early balneologische applications are in the baths of the Roman realm, in the middle kingdom of the Chinese and the Ottomanen. In Chaudes Aigues in the center of France exists the first historical, geothermal long-distance heating net, its beginnings to in 14. Century hand back.

Warmth is used nowadays in various way (heating market).A classical representation of the temperatures needed thereby gives the Lindal to diagram (Baldur Lindal, 1918-1997):

For most applications only relatively low temperatures are needed. From deep Geothermie can frequently the necessary temperatures directly be made available. If this is not enough, then those can Temperature by heat pumps to be raised, as this usually with the Geothermie near the surface happens. Here only few applications without heat pump are possible. The most important is the natural cooling, direct with that water with the temperature of the flat underground, thus the annual average temperature of the location, toBuilding cooling is used. This natural cooling has the potential to replace world-wide millions of electrically operated air conditioners. It is used only little however at present.

A further direct application is that ice-free stops of bridges and roads. No heat pump is needed also here, because the memory becomesby removal and line-to-store transfer of the warmth of the hot roadway in the summer regenerates. In addition also frost-protected shifting of water pipelines counts. The warmth contained in the soil lets the soil freeze in the winter only into a small depth.

Are suitable for the utilization of heat from deep Geothermieitself niedrigthermale depth waters with temperatures between 40 and 100 °C, as they seem to the north German lowlandses particularly in the South German mol ASS ASS, in the upper Rhine ditch and in parts. The Thermalwasser is brought to meters of depth usually from 1000 to 2500 over a promotion drilling to the surface, gives thatsubstantial part of its heat energy by heat-transfer agents to second, „the secondary “heating net cycle off. Cooled down it is injected afterwards over a second drilling again into the underground, into the layer, out of which it was taken.

Type of use energy
power output
annual average value
heat pumps 86,673 2,75
Baths 75,289 2.39
space heating of 52,868 1.68
greenhouses 19,607 0.62
industry 11,068 0.35
agriculture 10,969 0.35
drying process (agriculture) 2,013 0.06
cooling, snow melts 1,885 0.06
other use 1,045 0.03
total 261,418 8.29
direct use of the terrestrial heat world-wide
(conditions: 2004, source: Literature/statistics, 3.)

Generation of current

for generation of current became thoseGeothermie for the first time assigned in Larderello in the Toskana. 1913 were built there by count Piero Ginori Conti a power station, in which water vapour-claimant turbines produced 220 KW electrical achievement. Today there 400 MW river are fed into of Italy energy net. Under the Toskana meet thoseNorth African and the eurasische continental plate one on the other, which leads to the fact that magma is relatively closely under the surface. This hot magma increases here the temperature of the soil so far that an economic use of the terrestrial heat is possible.

Schemazeichnung für die Stromgewinnung aus Geothermie
Schematic diagram for the power generation from Geothermie

with the hydrothermalenGeneration of current are necessary water temperatures of at least 100 °C. Hydrothermale hot and drying steam occurrences with temperatures over 150 °C can be used directly for propelling a turbine. In Germany however the usual temperatures of geological warm water occurrences lie lower. Long time exclusively became Thermalwasser therefore the heat supply within the building rangeused. Again Organic Rankine Cycle developed - plants (ORC) make however a use possible of temperatures starting from 80 °C for generation of current. These work with an organic medium, which evaporates at relatively small temperatures. This steam propels the current generator over a turbine. An alternative to the ORC procedureis the potash well procedure. Here Zweistoffgemische are used, so for example from ammonia and water as media. For plants in a smaller capacity range (< 200 KW) are conceivable also motor drives such as stirling engines. Geothermie is basic loadable.

The generation of current from Geothermie is traditional inCountries, which over high enthalpy - stores order, in the temperatures of several hundred degrees in comparatively small depths (< 2000 m) to be found. Stores can be thereby, depending upon pressure and temperature, water or steam-dominated. With modern promotion techniques the cooled down fluids are reinjiziert, sothe fact that practically no negative impact on the environment as, more arises to sulfur smell.

Geothermie world-wide

Geothermie is an important renewable energy. A special contribution to their use here the countries, which over high enthalpy , make - stores order. There the portion of the Geothermie of the total energy supply of the country can be substantial,e.g.Geothermale energy in Iceland.

Direct use internationally

Country energy
per year
power output
annual average value
China 45,373 1.44
Sweden the 36,000 1.14
USA 31,239 0.99
Iceland 23,813 0.76
Turkey 19,623 0.62
Hungary 7,940 0.25
Italy 7,554 0.24
New Zealand 7,086 0.22
Brazil 6,622 0,21
Georgien 6,307 0.20
Russia 6,243 0.20
France 5,196 0.16
Japan 5,161 0,16
Sum 208,157 6.60
(source: Literature/statistics, 3.)

In the year 2005 world-wide plants with an output were installed of 27,842 megawatts (nearly 28 Gigawatt) for the direct use of Geothermie. These have energy in the order of magnitudefrom 261.418 Terajoule per year (72,616 Gigawattstunden per year), corresponds to a middle power output in the year of 8,29 GW or during a population of world 2005 of 6,465 billion Humans 1.28 Watts/humans - average primary energy consumption 2,100 Watts/humans - or 0.061% of the primary energy consumption of the world. The utilisation ratethe installed achievement amounts to thus about 30% (this characteristic number is important for the rough calculation of the economy of planned plants).

More largely than 5,000 TJ/Jahr the table shows countries with transformations of energy.

Particularly to emphasize are Sweden and Iceland. Sweden is geologically rather disadvantaged, has however througha consistent policy and public work this high portion with the use of renewable energies predominantly for heating reach.

Also in Iceland the use of this energy has a considerable portion of the power supply of the country (approx. 16%), see. Geothermale energy in Iceland. It is in the meantime world-wideOutrider in this area.

Generation of current internationally

generation of current from Geothermie concentrates traditionally on countries those over appropriate high enthalpy stores orders (usually volcanic areas). In countries, the this, how do not have Germany, knows river at comparatively low temperatures, as 100-150 is produced °C, or it is accordingly deepto bore. World-wide almost a boom occurred with the use from Geothermie to the generation of current. The installed achievement amounts to 2005: 8912 MW and thus 56,798 GWh/a electricity are produced.

Country new
MW e
Italy 254
Indonesia 250
Mexico 198
Kenya 92
The USA 60
Russia 50
Iceland the 30
Philippines 22
Costa Rica 18
(source: Literature/statistics, 1.)

Niederenthalpie stores are so far world-wide used little. In the future they will gain significance, since this use is possible everywhere and does not presuppose special geological conditions. Germany knows Führerschaft in this technologytake over. In November 2003 the first such power station of Germany, the Geothermie power station Neustadt Glewe was taken, in enterprise.

In Australia in Cooper Basin the first purely economic Geothermiekraftwerk on the basis HFR (Hot Fractured skirt) one provides. So far two drillings on over 4.000 m are depthgehohrt and an artificial tear system produces. The temperatures are with 270 degrees more highly than expected and also the artificially produced water route SAMness between the drillings are better than planned. 2006 are begun with the building of the power station after the Kalina procedure.

In the last 5 yearsthe generation of current was fully developed. Related to countries world-wide the increases for the period, indicated in the table, result 2000-2005.

Country portion of
the generation of current
in %
portion of
the heating market
in %
Tibet 30 30
San Miguel Iceland 25 no instruction
El Salvadore 1424
Iceland the 13.7 16.6
Philippines 12.7 19.1
Nicaragua 11.2 9.8
Kenya 11.2 19.2
Lihir Iceland 10.9 no instruction
Guadeloupe 9 9
Costa Rica 8.4 15
New Zealand 5.5,7.1
(source: Literature/statistics, 6.)

Related to the per head use of the terrestrial heat Iceland is today front runner with 200 MW einstalled total output (Geothermale energy in Iceland). The USA lead against it with an installed total output of 2000 MW e before Indonesia.

Situation in Germany

also in Germany is already common the direct use (heat pump heating system) and has high growth rates. The generation of current still is intothe beginnings, however a multiplicity of power stations is in the building or in planning.

From that at present well-known resources of hydrothermaler Geothermie could be made available up to 29 per cent of the warmth needed in the Federal Republic.

For Germany arises according to the numbers of the BMU [1] forthe year 2004 the following picture:

In the year 2004 from the Geothermie of 5.609 TJ/a (according to a middle power output of 0,178 GW in the year 2004) a primary energy consumption stands for the energy production in Germany in the same year of 14.438.000 TJ/a (according to a middle output of 458 GW)opposite. In the year 2004 0.04% of primary energy consumption in Germany were thus covered by Geothermie.

The Geothermie industry counts in Germany on an annual growth of 14 per cent. In the current year (conditions: March 2005) the conversion becomes on approximately 170 million euro and thoseInvestments on 110 million euro amount. About 10,000 humans work already directly or indirectly for the geothermal power supply (source, see literature/statistics, 2.).

Direct use

within the range of the deep Geothermie gives it in Germany to time to 30 installations with achievements over 100 KW. These carry together 105 outMW (source, see literature/statistics, 4.). Most of these mechanisms stand for north Germans

The north German area had geologically conditionally a large potential of geothermally usable energy in thermalwasserführenden pore memory of the Mesozoikums in a depth of1000 to 2500 m with temperatures between 50 °C and 100 °C. The geothermal central heating installation (GHZ) in new Brandenburg was one of the pilot projects for the use of the Geothermie.

The upper Rhine ditch offers Germany-far particularly good geological conditions (and. A. Temperature, heat flow, structure in the underground). At different locations are Projects in planning and in the building. For many regions concessions were already given. It is examined for example whether into long-distance heating - net of the Ruhr University and the professional school can be fed the Bochum terrestrial heat.

Baden-Wuerttemberg has exactly like north Rhine Westphalia an advancement program for terrestrial heat probe plants for smallResidential buildings presented, with a promotion of the drilling meters, see Web on the left of.

Additionally there are than 50,000 Geothermieanlagen near the surface in Germany more, with which heat pumps are used for the raising of the temperature. These have together an achievement of more than 500 MW. Compared with Sweden, Switzerland or Austriaa rather small market share. In the year 2000 it amounted to in Germany 2 to 3%, in Sweden 95%, and in Switzerland 36% (see also heat pump heating system)

generation of current

the first geothermal power station in Germany is 2004 in Mecklenburg-Western Pomerania as extension already of the 1994established geothermal heating station taken in enterprise. The electrical achievement of the Geothermie power station Neustadt Glewe amounts to up to 230 KW. From a depth of 2250 meters about 97 °C hot water is promoted and used for the current and heat supply. In the year 2004 the produced quantity of electricity amounted to 424000 kilowatt-hours (source: AGEE Stat/BMU), desired are annually approx. 1,2 millions Kilowatt-hours (corresponds to a middle achievement of 48kW, and/or. 137kW). Start-up represents a milestone in the development of the geothermal generation of current, which further projects will follow. The building of Geothermiekraftwerken experiences to time almost in Germanya boom. Many power stations are in the building or in planning. Most of it on the upper Rhine and in the upper-Bavarian would mol-eat. The local mining authorities assigned there numerous visiting permission (until 2005 nearly 50).

For the generation of current necessary warm servo IR with high temperatures are in Germanyonly in large depth available. Theoretically nearly everywhere a drilling with the necessary depth can take place in the country. With achievement sizes of 20 to 50 MW combined heat and power stations could make available about 30 per cent of the German current consumption. The temperatures necessary for the enterprise to open, is ratherfinancial and no technical problem. Research work for use deeply more lying to a large extent wasserundurchlässiger rocks runs and promises the possibilities for the generation of current further to increase. A study of the German federal daily indicates the potential of current production as 10 21 joules.

Planned Geothermieanlagen in Central Europe
Geoth. Achievement
Electrical achievement
promotion rate
drilling depth
planned start-up
Northern Germany
Bremerhaven 0.5 0.065 90 5,000 shut down
largely Schönbeck 1.0 ,150 < 25 4,294 2006
Neustadt Glewe 6.5 0.21 98 119 2,250 2003
South West German country
bath Urach 6-10 approx. 1,0 ,170 48 4,500 shut down
Bruchsal 4,0 approx. 0,5 ,120 72 2,000 2007
Karlsruhe 28.0 > 150 ,270 3,100 2007
Landau approx. 2,5 ,250 3,000 2006
open brook 25-30 4.8 ,360 2,000 2006
Riedstadt 21.5 ca.3, 0 ,250 3,100 2007
Speyer 24-50 5.4 ,120 2005?
South Germany
Isar south 30.0 2,0 ?
Unterhaching > 30 ,3,9 < 540 3,350 2006
Soultz 30.0 6.0 ,200 ,240 8,084 2005
source: Greenpeace 2000MW - clean!

National supporting measures

  • incentive for market for favour of renewable energies
  • of programs of the KfW
  • of advancement programs of countries and municipalities

economic aspects

the small use of the everywhere existing and of the energy offerago free Geothermie lies in the fact justified that both the heat flow, with ~0,06 Watt/m ² and the temperature increase with the depth, with ~3°C/100 m in the accessible parts of the earth's crust, apart from special locations, so small it are that a use at times of low energy prices not economicallywas. By <math> of the CO_ {2}< /math> - problem and the foreseeable shortage of the fossil sources of energy a stronger geological investigation and a technical advancement of the Geothermie began.

Since the actual energy, which is free Geothermie, becomes the economy of a Geothermienutzung particularly by the capital outlays (interest) and maintenance coststhe plants determines.

Under the present political basic conditions (renewable energy law) an economy is with larger Geothermieanlagen also in Germany in many areas, like in e.g. Upper Bavaria, upper Rhine ditch and north German basin, attainable. Larger Geothermieanlagen is fundamental (over 0,5 MW and with a depth of moreas 500 m) always afflicted with certain Fündigkeitsrisiken, since the deeper earth layers are explored evenly only punctually and often in small extent. The temperatures which can be found can be prognosticated usually quite well, those with hydrothermalen plants however particularly relevant pouring quantities are frequently not good howeverforeseeable. Recently however risk insurance is offered for it.

The terrestrial heat use near the surface for the heating of buildings by means of a heat pump is already competitive and is characterised by very low operating cost. Heat pump heating systems usually consist of or several terrestrial heat probe (n) and a heat pump. 2004 became inGermany about 9,500 new plants established, the existence exceeds 50.000. In Switzerland there was 2004 approximately 4,000 new plants with terrestrial heat use. The market share in Germany is however very small contrary to countries such as Sweden or Austria.

With the operating cost the stability that playsPlants against wear (e.g. moved parts of a heat pump or a stirling engine) a role. With open systems corrosion can result from aggressive components in the warm-transporting water (all parts in the earth and the heat-transfer agents). These initially meaning problems are however today to a large extent technically solved.

Ecological aspects

the Geothermie fulfills the criteria of the lastingness. It is in the strict sense not completely regenerativ, but their Potenzial is very large. Theoretically alone the energy stored in the upper 3 kilometer of the earth's crust would be sufficient, around the world for approximatelyTo supply 100,000 years with energy. Geothermie is one of the few renewable energies, which is basic loadable during the generation of current. It makes therefore a crucial contribution with the organization of a Energiemixes from regenerativ energies. After the conceptions of the industry become by Geothermie up to the year 2020more than 20 million tons carbon dioxide saved. The costs of a ton <math> CO_ {2}< /math> Saving are appropriate with approximately 70 €/t (comparison: Fotovoltaik 2210 €/t).

See also


sources of statistics

  1. Bertini, R.:World geothermal generation 2001-2005. World GeothermalCongress, Antalya, 2005.
  2. Image campaign: Infinitely much energy
  3. Lund, J. et al.:World wide direct use OF geothermal energy 2005. World Geothermal Congress, Antalya, 2005.
  4. Schellschmidt, R. et al.:Geothermal energy use in Germany. World Geothermal Congress, Antalya, 2005.
  5. Steffansson, V.:World geothermal assessment.World Geothermal Congress, Antalya, 2005.
  6. Lund, J.:Ground Heat - worldwide utilization OF geothermal energy. Renewable Energy World. 2005


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Wiktionary: Geothermie - word origin, synonyms and translations
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