Geothermal power plant Unterhaching
| Geothermal power plant Unterhaching | |||
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| location | |||
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| Coordinates | 48 ° 3 '25 " N , 11 ° 35' 53" E | ||
| country | Germany | ||
| Data | |||
| Type | Geothermal power plant | ||
| Primary energy | Geothermal energy | ||
| power | 3.36 megawatts electrical 70 megawatts thermal |
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| operator | Geothermal energy Unterhaching GmbH & Co. KG | ||
| Project start | 2004 | ||
| Start of operations | 2007 | ||
| Website | www.geothermie-unterhaching.de | ||
The Unterhaching geothermal power plant is a geothermal power plant with an electrical output of approx.3.36 megawatts and, in the final stage, 70 megawatts of thermal output. The project in Unterhaching , Bavaria , was started in 2004 as the Unterhaching geothermal project and has been supplying district heating to the community's households since 2007 .
aims
On the one hand, the aim was to use the thermal water area of the southern German Molasse basin, which is important from the fundamental discovery, for a combined electricity and district heating power plant in Germany. On the other hand, the Kalina cycle is being used for the first time in Germany in the power generation set up by Siemens , while the first German geothermal power plant, the GKW Neustadt-Glewe , and the first industrial GKW Landau rely on the Organic Rankine Cycle process . While the ORC process uses thermal water to evaporate organic liquids, which then drive a turbine, the Kalina process evaporates an ammonia- water mixture. In principle, the Kalina process enables a higher degree of efficiency , but has not yet been well tested technically. The generation of electrical energy began on June 2, 2009.
The power plant gets its useful heat from the thermal water of a Malmkarst layer through a borehole with a discharge of 150 liters per second. The water extracted from a depth of 3,350 meters has a temperature of 122 ° C. After use, it is injected back into the subsurface in a second, 3,590 meter deep borehole.
The Kalina plant for generating electricity from geothermal energy is to be shut down in 2018. The process had a pilot character and is no longer economically viable. According to the operator, it was interesting in the initial phase, when there were hardly any district heating customers, to convert the energy into electricity. With around 7,000 households, district heating has more participants than ever planned in 2017, so that the focus of energy use has shifted to it.
The operators of the pilot project Unterhaching
The Unterhaching geothermal project was tackled by the community of Unterhaching in close cooperation with the Federal Ministry for the Environment through the specially founded Geothermie Unterhaching GmbH & Co. KG. The project support was provided by the auditing and consulting company Rödl & Partner .
advancement
The way for the project was paved on the one hand by a specially designed discovery insurance and on the other hand by funding from the Federal Environment Ministry.
Project progress
| January 26, 2004 | The starting shot for drilling the first borehole. |
| February 18, 2004 | Drilling kick-off event in Unterhaching with the then Federal Environment Minister Jürgen Trittin, the representative of the Bavarian State Ministry for Economic Affairs, Infrastructure, Transport and Technology Bernhard Wiesner and the then Mayor of Unterhaching Dr. Erwin Knapek. |
| September 27, 2004 | The production well has found discovery. |
| June 2, 2006 | Start of drilling the second hole (injection hole). |
| November 21, 2006 | Topping-out ceremony for the Kalina plant. |
| January 18, 2007 | Reaching the preliminary final depth of the second well. |
| June 18, 2007 | Start of trial operation of the heat supply, initially via the redundant heating plant with heating oil. |
| 4th October 2007 | Heat supply with geothermal energy. |
| June 2, 2009 | Official commissioning of the power supply by the Federal Environment Minister. |
Geology and processes in Unterhaching
The process of hydrothermal geothermal energy is used in Unterhaching : The Malmkarst , a water-bearing rock layer ( aquifer ), is located at a depth of approx. 3,000 - 3,500 meters . From there, the hot water is pumped to the surface for further use. To use the thermal water, a double drilling was carried out: One borehole is used to convey the thermal water, which is very rich in minerals, and the other is used to return it to the rock layer for reinjection. The two wells were connected by a 3.5 km long thermal water pipe.
| drilling | depth | temperature | Bulk |
|---|---|---|---|
| 1st hole (2004) | 3,350 m | 122 ° C | 150 l / s |
| 2nd hole (2007) | 3,580 m | 133 ° C | > 150 l / s |
Generation of electrical energy
.JPG)
The system for generating electrical energy was built by Siemens AG with an installed capacity of 4.1 MW el , the average output is 3.36 MW el . This means that up to 10,000 households can be supplied with electrical energy on a statistical average.
For the first time in Germany, a plant for generating electrical energy using the Kalina process was built in Unterhaching . This technology is particularly advantageous at low thermal water temperatures. As the working fluid in the cycle there is ammonia used since it supports the generation of electric energy to 100 ° C possible from 90th Ammonia has a boiling point of −33 ° C, which is significantly lower than that of water, but the toxic ammonia must be prevented from escaping into the environment in the system with greater safety.
District heating
In 2006, the construction of the district heating network began, which by mid-2008 covered a length of more than 22 km and reached a connected load of almost 40 MW. With the start of the supply by geothermal energy (October 4, 2007), 7,000 tons of CO 2 emissions could be saved in the first heating period up to and including April 2008 . Since geothermal energy can be used at any time and without fluctuations, the base load is covered exclusively by geothermal energy. During peak and downtimes, however, the supply is ensured by a redundant heating plant that is operated with fossil fuels .
Sources and individual references
- ↑ Geothermal energy Unterhaching - data and facts
- ↑ Geothermal plant Unterhaching: Nationwide largest geothermal power plant in operation on klimaktiv.de
- ↑ BINE Information Service: projektinfo 10/09
- ↑ Münchner Merkur: Pilot project failed , December 12, 2017
Web links
- Official website of Geothermie Unterhaching
- Information portal on geothermal projects by Rödl & Partner
- Spiegel online: How a small town supplies itself with clean energy
- Federal Environment Ministry: Demonstration project "Construction and operation of a geothermal power plant for electricity and heat generation" , status: September 30, 2008
- Federal Environment Ministry: Funding recipients: Geothermie Unterhaching GmbH & Co. KG , as of September 30, 2008
- Official website of the community of Unterhaching