Landau geothermal power plant

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Landau geothermal power plant
Scheme of the use of geothermal energy on the construction sign of the GKW Landau. The wet cooling tower shown is outdated.
Scheme of the use of geothermal energy on the construction sign of the GKW Landau. The wet cooling tower shown is outdated.
location
Geothermal power plant Landau (Rhineland-Palatinate)
Landau geothermal power plant
Coordinates 49 ° 11 '11 "  N , 8 ° 7' 22"  E Coordinates: 49 ° 11 '11 "  N , 8 ° 7' 22"  E
country Germany
Data
Type Geothermal power plant
Primary energy Geothermal energy
power 3 megawatts net
operator geox GmbH
Project start 2004
Start of operations 2007
turbine Organic Rankine Cycle Turbine
Energy fed in 2013 22.3 GWh
Website www.geox-geothermie.de
f2

The geothermal power plant Landau was a geothermal power plant in the Palatinate Landau , which was in operation from 2007 to 2014 with an electrical output of 3  MW .

The power plant was built on the site of a former French barracks by the company geo x , which until August 2013 was a 50 percent subsidiary of Pfalzwerke and EnergieSüdwest . Then it came to 90% in possession of Geysir Europe GmbH , with an option to redeem at any time on the remaining ten percent, which EnergieSüdwest AG kept.

It gets its useful heat from deep water at 159 ° C from a shell limestone layer at a depth of around 3000 m. 70 liters per second are obtained and evaporate isopentane through a heat exchanger . The steam drives a turbine made by the US company Ormat Technologies , which in turn drives an electrical generator . The steam is cooled down again via a large air cooler and liquefied and goes back into the evaporator. In winter, the residual heat (5 MW) is to be used for district heating purposes in the future (2009/10) . The cooled water is pressed back into the ground. While the production well and the reinjection well are just a few meters away above ground, the inclined drilling means that the extraction point in the west and the re-injection point in the east are 1462 m apart.

The investment costs amounted to around 21 million euros, the majority of which went to the two wells.

The geothermal power plant in Landau went into operation as the first geothermal power plant in the open geothermal area of ​​the Upper Rhine deep trench . The French geothermal power plant in Soultz-sous-Forêts , where the hot-dry-rock method is being tested, in which layers rich in water are not exploited, as in Landau, but fissures and cracks in hot granite are first blasted through which water is then passed , started in 1997, but did not go into operation until summer 2008.

After the seismic activities in 2009, the ground upheavals from 2013 to 2014 and the resulting resentment of the Landau population and the city council, the future of the geothermal power plant is still uncertain, despite a takeover of the majority by another company that is aiming for the third well.

Technical details and data

Production well and reinjection well of the Landau GKW. The blue in the middle is the delivery well with the rod-type deep pump, on the right red the reinjection well, in the back in the middle the pump house for the reinjection, on the left part of the dry cooling

The power plant has 7600 hours of use per year. The amount of electricity generated is sufficient for 6,000 households and saves 11,000 tons of carbon dioxide a year. 10 to 12% of the extracted geothermal energy is used. The power plant produces more than 3 megawatts of power, but after deducting internal requirements, especially for the feed pump and the injection pump as well as the fans of the dry cooling system, 3 megawatts remain. Due to the high pressure in the depths, the hot water in the borehole rises to a depth of 40 meters, so only this height has to be pumped up. For this purpose, a rod-type deep pump was chosen, as is often used in oil production. Since there is no suitable body of water for water cooling, a dry cooling system with air cooling was selected.

Because isopentane is used to generate steam, power generation at Landau GKW belongs to the organic Rankine cycle process, which competes with the Kalina cycle process . The Organic Rankine Cycle process was selected because it has been technically well proven. Like the choice of the geologically well-known situation, this should reduce the risk of failure.

In order to avoid contamination of the water, the oil-suspected Pechelbronn layers were also sealed during drilling .

From 2008 to 2013, around 88.5 GWh of electricity was fed into the grid. In 2013, the power plant produced around 15,300 MWh of electrical and 7,000 MWh of thermal energy with an availability of 98.4% .

Project history and construction

Project development and approval

The project development phase, i.e. the examination of the theoretical feasibility, the technical project planning, the financing and the obtaining of the mining and building permits for the power plant, lasted until 2003 and 2004, the actual project start was in 2004. Because of numerous oil wells in the area of Landau, the sequence of layers and the deep temperatures of the area were quite well known. Instead of complex seismic measurements with vibrating plates or the like, geo x bought this data from the oil producers.

The project, funded by the State of Rhineland-Palatinate (Ministry of Economic Affairs) and the federal government (Ministry of the Environment), was financed by LRP Landesbank Rheinland-Pfalz and Sparkasse Südliche Weinstrasse .

Production well

The first drilling for the extraction of the process water and the testing of the productivity, i.e. the productivity, took place in 2005. The actual drilling took place from August 5th, 2005 on 63 days until October 7th, 2005. The drilling was sloped to the west from a certain depth, with a deflection of up to 29 degrees. For the depth of 3000 meters, 3300 meters of drilling were required. The drilling progress was approximately between 70 and 110 meters per day.

Reinjection drilling

The second borehole for injecting the cooled water and testing the absorption capacity of the borehole, i.e. its injectivity, took place from January 22nd to March 15th, 2006. Although the injection borehole was made deeper and to the east in the direction of flow of the groundwater towards the Rhine, At a depth of 3,170 meters, which required 3,340 meters of drilling, the drilling took only 53 instead of 63 days. Since the drilling company knew the sequence of layers from the first drilling, it was able to choose the optimal drill bit right away and thus reached 70 to 140 meters per day.

Plant construction and commissioning

The construction of the systems and buildings, i.e. the geothermal pump, the pipe system, the power plant with heat exchanger, turbine, generator & cooling, the pump house for the pressing, the transformer and the information building took place in 2006 and 2007.

  • The contract for the power plant construction was awarded in July 2006.
  • The circulation test was carried out from March to May 2007.
  • The cooling was installed in May 2007.
  • The turbo generator was built in August 2007.
  • Trial operation began in November 2007.
  • The official commissioning with power generation took place on November 21, 2007.

The 2009 earthquakes and their effects

Microquake and security issues

Heat exchanger of the Landau geothermal power plant, in which the thermal water evaporates the carrier medium isopentane. You can also see the preheater and evaporator, as well as the steam line to the turbine in the upper part of the picture.
Turbine generator set of the power plant manufactured by Ormat . In the middle is the turbine, into which the steam flows from above. To the right of the turbine, the generator is located under a white panel. The steam flows through the green pipe to the left of the turbine to the dry cooler.
The steam rises to the dry cooling system via the green pipe.
Reminder of the main costs: The drill heads that were used at Landau GKW.

On August 15 and September 14, 2009, light seismic events of magnitude 2.7 and 2.4 on the Richter scale occurred in Landau. The Rhineland-Palatinate Ministry of the Environment has commissioned a commission of experts to examine this seismicity for a possible connection with power plant operation. On November 10, 2009, the State Ministry of Economics announced that the plant met the criteria for resumption of trial operation. Among other things, the insurance coverage for the power plant was increased and a measuring network was set up in order to be able to precisely determine the surface vibrations of seismic events in the future.

The expert commission chaired by Christian Bönnemann, head of the “Central Seismological Observatory” department of the Federal Institute for Geosciences and Natural Resources , came to the conclusion that a causal connection between the seismicity since November 2007 and geothermal energy generation in Landau is very likely. In the case of the stronger earthquake on August 15, 2009, the strength was classified in such a way that it was in an area in which “slight, non-structural damage to sensitive buildings such as plaster cracks can no longer be completely ruled out”. However, damage to the supporting structure or moderate, non-structural damage is very unlikely. The August 15, 2009 quake occurred less than two kilometers from the borehole landing points below the city center at a depth of 2.8 km. This and the increase in not noticeable but measurable microquakes since the plant was put into operation was interpreted by the commission as proof of the assumption that the operation of the geothermal power plant was the cause of the earthquake. The commission identified increased pressure in the rock pores as the direct cause of the microquake, which is caused by the back-pressing of the extracted thermal water. Existing tectonic tensions could be released because the higher pore pressure reduces the load-bearing capacity of individual layers. A tried and tested means of preventing future earthquakes is therefore to reduce the flow rate and the pressure in the borehole. Two highly sensitive borehole measuring stations should also be installed. Since earthquakes had already been announced two days in advance by increased microseismicity, their seismic measurements should be fed into a data center in real time and a binding reaction should take place to such increased activity, a reduction in the feed, which would then prevent earthquakes with a high degree of probability. The operators should cooperate closely with authorities and research and develop a risk analysis.

Mediation process

Because of the safe continued operation of the plant and the further development of geothermal energy, the state government is aiming for the State Secretary for Economic Affairs, Alexander Schweitzer , to initiate a mediation process between operators and the five citizens' initiatives that have formed out of concern about the dangers of geothermal energy. The aim is to give the clearest possible yes to geothermal energy as part of a mix of renewable energies. They wanted the system in Landau to be connected to the grid with extreme caution in order to be able to see how geothermal energy could work in practice. Prof. Jan Ziekow , Director of the German Research Institute for Public Administration Speyer , was selected as mediator .

A third drilling was canceled in 2013

In mid-May 2013, the supervisory board of the Landau energy supplier EnergieSüdwest decided not to contribute to the costs of a third well for the power plant, the financing of which the federal government would have contributed 4.3 million euros. EnergieSüdwest cites economic reasons in connection with the seismic situation in the southern Palatinate, also taking into account the problems at the Insheim geothermal power plant . In addition, EnergieSüdwest does not want to subsidize the power plant operation any further. EnergieSüdwest takes the position that the economic situation has changed. This is contested by the Pfalzwerke.

In mid-August 2013, Daldrup & Söhne AG announced that it had acquired 40 percent of the shares in geo x from EnergieSüdwest through its 75.01% subsidiary Geysir Europe . According to Daldrup, the third well is to begin in 2013. Another press release announced in December 2013 that Daldrup & Söhne, through its subsidiary Geysir Europe GmbH, had also acquired the previous stake in Pfalzwerke and now owns 90% of geo x GmbH. In the same report, the expected electricity (14,000 MWh) and district heating (7,000 MWh) production for 2014 is announced. It is also said that a third well is planned in 2014 and that this and further optimization measures will result in an increase in power plant output of 40 to 50% over the next few years.

Soil elevations in Landau from 2013 and shutdown in March 2014

In October 2013, changes in the terrain were found during survey work on the grounds of the State Horticultural Show . These results were confirmed in December 2013. The elevation of the terrain continued during the two measurements. The city council of Landau was informed in January 2014. Further information was obtained at the end of the month, including from two geologists and the operator of the geothermal power plant. The State Office for Geology and Mining informed the mayor of the city that there was no urgent need for action. In mid-February, decisions are made to expand the network of measuring points and to use satellite images to estimate the period, strength and area of ​​the uplift . Airbus Defense and Space is commissioned for the latter .

At the end of the month, road damage to the road at the geothermal power plant is found. The damage pattern worsened from early to mid-March. On March 14, 2014, horizontal terrain shifts around the power plant were also detected for the first time. Four days later, the State Office for Geology & Mining announced that the operator had shut down the geothermal power plant as a precaution and was now planning various tests. In addition, a committee of experts was set up to investigate the causes of the terrain shifts. According to the state office, this will be carried out in close cooperation with the city of Landau and the Structure and Approval Directorate South .

On March 24th, the State Office for Geology & Mining announced that there could be a connection between the changes in the terrain and the geothermal power plant and that the resumption of power plant operation will only be approved if it becomes clear that the power plant does not pose a threat to the general public. This would be the case, for example, if the power plant was not responsible for the uplift and shifting of the ground or if the problem area in the system can be clearly identified and remedied and a further occurrence of the problem can be excluded. At the same time, a temporal, spatial and causal connection between the changes in the soil in the south of Landau and the oil production in the northern urban area of ​​Landau, which has been carried out there since 1955, are definitely excluded. The uplifts in the north of Landau in the past are most likely not due to oil production. Furthermore, measurements will continue to take place in a tight time frame.

On March 28, the State Office for Geology & Mining also announced that the technical reviews of the geothermal boreholes had not yet been completed and that the groundwater was currently being examined in cooperation with the responsible water authority. Current measurements show further changes in terrain.

Landau's city council also passed a resolution on the geothermal power plant at the end of March in which the state of Rhineland-Palatinate demands that power plant operations only be resumed if the safety of the Landau citizens is ensured. In addition, there is a demand that the permit for the third well be refused and that the geothermal power plant be shut down in the medium term. The reason given is that the Landau power plant provided a lot of knowledge about geothermal energy in the Upper Rhine Graben, but has meanwhile become an “ unacceptable burden ” for the city of Landau.

On April 3, the State Office for Geology & Mining informed the responsible authorities that increased concentrations of salts and heavy metals had been found in the groundwater from the area of ​​the power plant. However, there is no acute danger to the drinking water supply of the city of Landau, according to the responsible water authorities. However, further precautionary measures have been taken. On April 8th, the SGD Süd gave the all-clear and announced that groundwater samples from various extraction points from April 4th show no contamination by thermal water. According to SGD Süd, groundwater samples from April 14th would not show any pollution from thermal water. Only the sprinkling fountain on the state horticultural show grounds showed an increased arsenic content in both samples, which, however, probably had more of a geological cause. The fountain was shut down as a precaution.

Eveline Lemke and Ulrike Höfken announced on April 9th ​​that the State Office for Geology & Mining had found clear signs of leaks at the Landau geothermal power plant, there had probably been a leak in a seal and a deep borehole. The exact location of the leaks is currently being tracked down, the thermal water that escaped as a result may have caused the ground uplift. The investigation of the groundwater would be further expanded, the State Office for Geology & Mining had commissioned an expert opinion to determine the amount and location of the thermal water that had escaped and, together with the water authorities, ordered a 500 m deep borehole for further groundwater investigation; In addition, Minister Lemke initiated the investigation of the power plant in Insheim and similar wells in Rhineland-Palatinate, according to the press release.

The results of the satellite evaluation were available on May 16: they largely confirm the previous findings. At the same time, survey data was published again. There would have been no new horizontal shifts worth mentioning, but the power plant site and the surrounding area have again sunk vertically by several millimeters (up to 9 mm). The area has also sunk by a few millimeters in the wider area surrounding the power plant and at the future “Am Ebenberg” residential park.

The following measurements, the results of which were published on May 30th, showed that the situation was apparently stabilizing, only in the direct vicinity of the power plant (2-4 mm) and at measuring point building 111 of the residential park “Am Ebenberg” (2 mm ) slight subsidence was found.

On June 27, the city of Landau announced that the State Office for Geology & Mining no longer saw any reason not to start construction work in the “Am Ebenberg” residential complex. Only in the direct vicinity of the power plant (up to a maximum of 5 mm) and at the measuring point building 111 (3 mm) were any subsidence found. Vertical movements are still no longer measurable. The measurement data published with this message would thus confirm the reduction in movements observed during the last measurement. The frequency of measurements was then reduced.

On July 1, 2014, Daldrup & Sons announced that the ground uplift had been facilitated by a leak in a seal three meters below the surface. This leakage of the reinjection well would have existed for several years, the consequences of the leakage could have been avoided through proper operational management and monitoring, according to an expert opinion.

The city issued a statement that same day. In this it is described that the main cause of the terrain movements is not the leakage at a depth of three meters, but, according to oral and written reports from the State Office for Geology & Mining, another leakage at a depth of up to 500 meters, because soil movements of this magnitude can only be greater Depth arise. The leakage at shallower depths was repaired at short notice, according to the state office. Incidentally, the ground movements in the immediate vicinity of the power plant have still not completely subsided.

Planning for recommissioning from 2014

The resolution on the geothermal power plant passed by the Landau City Council at the end of March requires that power plant operations only be resumed if the safety of the Landau citizens is ensured.

Daldrup & Söhne announced in July 2014 that it was aiming to resume operations in late summer 2014. Before that, however, new security, monitoring and reporting systems would be installed and further modernizations would be carried out for a total of two to three million euros.

In August 2017, the State Office for Geology & Mining approved the special operating plan for the "construction / revision and recommissioning of the primary circulation system."

At the end of November 2018, operations were resumed on a trial basis, but stopped after two days due to an accident.

By the beginning of 2020, Daldrup & Söhne AG sold its shares in Geysir Europe GmbH, including the shares in Landauer Kraftwerk, to the Luxembourg fund IKAV Invest S.à rl as part of a realignment

Web links

Commons : Geothermalkraftwerk Landau  - Collection of pictures, videos and audio files

Sources and individual references

  • The main source is a lecture by student trainee Andreas Keck in the information room of the power plant and the geox website, see web links
  1. ↑ a b c d Daldrup & Söhne: Daldrup & Söhne AG prepares the restart of the geothermal power plant in Landau - background information on the ground elevation and the restart of the power plant in Landau. Retrieved August 7, 2014.
  2. ^ Energie Südwest AG: Geothermal energy in Landau on the right track , August 2013. Accessed on August 5, 2014.
  3. ↑ Website of geo X GmbH. Retrieved on August 5, 2014. ( Memento from September 22, 2013 in the Internet Archive )
  4. ↑ basisEnergie No. 08: Geothermal energy. on the website of the BINE information service.
  5. ^ Citizens 'Initiative Geothermie Landau eV: Information from the Citizens' Initiative Geothermie Landau eV Retrieved on August 7, 2014.
  6. ↑ a b Daldrup & Söhne AG acquires shares of Pfalzwerke AG in the geothermal power plant Landau id Pfalz - press release Daldrup & Söhne. Retrieved August 6, 2014.
  7. ↑ Daldrup & Söhne AG press release: Daldrup & Söhne AG shortly before two geothermal power plants are in operation . Retrieved August 6, 2014.
  8. ↑ Construction sign
  9. ↑ Der Spiegel 39/2009: The Landau Quake - Von Bethge, Philip and Lauenstein, Christian
  10. ↑ The operator of the Landau geothermal power plant is preparing to recommission it ( Memento from December 13, 2010 in the Internet Archive )
  11. ↑ git: " Very likely", expert commission sees connection between geothermal energy and earthquakes in Landau. In: The Rhine Palatinate . December 9, 2010, page: Südwestdeutsche Zeitung.
  12. ↑ Energy: geothermal power plant probably responsible for quakes. on focus.de , December 8, 2010.
  13. ↑ Landau geothermal power plant: EnergieSüdwest decides against third drilling, press release of the City of Landau from May 14, 2013.
  14. ↑ EnergieSüdwest does not give any money for a third well in Landau - future of the geothermal power plant uncertain. ITG information portal deep geothermal energy, May 15, 2013, accessed on May 23, 2013 .
  15. ↑ Daldrup & Söhne acquires 40 percent of the shares in the Landau geothermal power plant. ITG information portal deep geothermal energy, August 19, 2013, accessed on October 5, 2013 .
  16. ↑ floor elevations Landau: chronology. Retrieved August 6, 2014.
  17. ↑ State Office for Geology & Mining: Site surveys in Landau / geothermal power plant switched off . Retrieved August 6, 2014.
  18. ↑ State Office for Geology & Mining: Site surveys in Landau - Current development - Power plant remains temporarily shut down. Retrieved August 6, 2014
  19. ↑ State Office for Geology & Mining: Terrain surveys in Landau - current development - power plant remains switched off. Retrieved August 6, 2014.
  20. ↑ a b City Council Landau: Resolution on the geothermal power plant . Retrieved August 6, 2014.
  21. ↑ State Ministry for Economic Affairs, Climate Protection, Energy & State Planning: Geothermal power plant Landau: Land checks groundwater contamination at the geothermal power plant. Retrieved August 6, 2014.
  22. ^ Structure and Approval Directorate South: Results of the samples are available. Retrieved August 7, 2014.
  23. ↑ Structure and Approval Directorate South: The result of the reference measurement is available: Public drinking water supply for the city of Landau is still not at risk. Retrieved August 7, 2014.
  24. ↑ State Ministry for Economics, Climate Protection, Energy & State Planning / State Ministry for Environment, Agriculture, Food, Viticulture & Forests: Geothermal power plant Landau: Lemke / Höfken: Leakage at the geothermal power plant suspected - Landau drinking water unpolluted. Retrieved August 7, 2014.
  25. ↑ Stadtverwaltung Landau: Terrain changes in Landau: Final report of the satellite evaluation is available. Retrieved August 7, 2014.
  26. ↑ Landau city administration: New measurement results on changes in altitude. Retrieved August 7, 2014.
  27. ↑ Stadtverwaltung Landau: State Office for Geology & Mining: "From an engineering geological point of view, it is no longer necessary to wait for construction to begin" - New measurement data on the changes in the terrain in Landau. Retrieved August 7, 2014.
  28. ↑ Statement from Lord Mayor Hans-Dieter Schlimmer on the press release of Daldrup & Söhne AG "" Daldrup & Söhne AG prepares the restart of the geothermal power plant in Landau - background to the ground elevation and restart of the power plant in Landau. Retrieved August 7, 2014.
  29. ↑ Daldrup & Söhne: Authorities grant approval of the special operating plan for the construction / revision and recommissioning of the systems of the geothermal power plant in Landau . Press release August 8, 2017.
  30. ^ After an incident: Landau geothermal power plant shut down again , on December 3, 2018 on pfalz-express.de
  31. ↑ Daldrup & Söhne AG press release: Daldrup & Söhne AG: As part of the announced realignment, Daldrup & Söhne AG is selling the Geysir group with geothermal power plants to the IKAV group. In: www.dgap.de. January 15, 2020, accessed January 25, 2020 .