Erding, Germany

Geothermal energy for district heating

Erding, in Bavaria, lies in one of Germany's three major geothermal zones, the Molasse Basin. Since 1989, geothermal water has been used there to meet a demand for heating that keeps growing.

A custom-designed BROAD absorption heat pump recovers heat from geothermal water, drawn from a depth of about 2,300 m at 63 °C, and cools it down to 25 °C before it is reinjected into the ground. It runs on steam from a nearby combined heat and power (CHP) plant and heats the district heating water from 62 °C to 80 °C.

Thanks to its titanium tubes, the geothermal water enters the unit directly, without an intermediate heat exchanger, while corrosion and the impact on water quality are kept to a minimum. The resource is preserved and can be used sustainably.

• Unit type: single-effect steam absorption heat pump × 1 unit
• Heating capacity: 7.4 MW
• Heat source: 10 bar(g) steam from a nearby CHP plant
• Geothermal water: inlet 61 °C, outlet 25 °C
• Heating water: district heating network (inlet 62 °C, outlet 80 °C)
• Use: district heating
• Equipment: titanium tubes, double-section technology, custom monitoring instruments
• Payback period: 2 years