Atlas Copco to provide turbine for Garching geothermal project in Bavaria, Germany

Drilling rig on site in Bavaria, Germany (source: Silenos Energy)

Alexander Richter 20 Oct 2019

During a press briefing this week, the managing directors of Silenos Energy GmbH presented on the planned plant installations and the current status of the construction work at its Bruck geothermal project in Garching, Bavaria. They presented on the specifics of the planned co-generation plant, water cooling and the cogeneration thermal plant (Blockheizkraftwerk, BHKW) with black start capability, allowing the plant to be started without relying on external electric power network to recover from a total or partial shutdown.

The Managing Directors of the Joint Venture, Christian Steinbauer of Strabag and Oliver Friedlaender of RAG, explained in detail the use of the planned buildings, which are currently being errected on site of the drilling site in Garching. They further highlighted that they welcome the initiative of Minister of State Hubert Aiwanger (we reported): “With a Bavarian master plan for the expansion of geothermal energy and the promised funding, regenerative technology can exploit its strengths in combined power and heat generation,” said Christian Steinbauer. “Thus, the Bavarian state government provides a template for the heat turnaround and Bavaria is a pioneer in Germany,” said Oliver Friedlaender the importance of the speech of state ministers Hubert Aiwanger.

Water cooling and black start capability

Special attention was paid to the planned water-cooling, as the managing directors pointed out. This increases the efficiency of the plant and the guarantee of continuous plant operation. Three gas-powered cogeneration units, each with a capacity of 900 kW, are provided to the pump and power plant. During the planning, care was taken to ensure that the system can be supplied with liquified (LNG) or compressed natural gas (CNG) even in the event of a blackout and is thus able to start black.

The heat from the CHP can then be used together with the decoupled district heating. However, no specific plans have yet been mentioned. Silenos Energy GmbH intends leave the utilisation of the heat for the district heating network of up to 6.9 MW thermal to an external heat supply operator.

The power plant

The power plant with a capacity of 4.3 MW will be equipped by Strabag Umwelttechnik GmbH with a turbine from Atlas Copco. The commissioning should take place in August / September 2020 and be used with Isobutan as working fluid. “So far, we are on schedule with the project and expect to produce the first electricity in one year,” explains Christian Steinbauer.

Summit ESP delivers the feed pump

Silenos Energy GmbH took over the project in 2017 and successfully completed the drilling work on the doublet in January of this year. The two wells, which were drilled into the same fault zone at almost the same depth, opened up deep underground water at a temperature of 125 degrees Celsius in the Malmkalk of the Oberjuras. The second well is to be used as a production well, the first well for re-injection.

At the Praxisforum Geothermie.Bayern geothermal conference earlier this month, Oliver Friedlaender announced that the pump was purchased from Summit ESP.  “Summit has made a best offer with a very good service package,” emphasized Oliver Friedlaender. “We expect a significantly improved pump operation due to the many years of experience of the employees.” Silenos Energy GmbH expects an average of 8,300 full-load hours per year for system operation. As the operator survey at the Geothermie.Bayern practice forum has shown, this is a realistic assumption.

Source: Our German partner website of TiefeGeothermie