HDR - deep geothermal heat

A method which can be used to harness geothermal energy at great depths for power and heat supply worldwide has reached the implementation stage in the Swabian town of Bad Urach: in Germany alone, the Hot Dry Rock method (HDR) could be used in the long-term in 95 % of places and contribute to securing base load.

The HDR system basically consists of at least two depth drillings and one subterranean heat exchanger. The heat exchanger consists of natural joints in plutonite rock which are extended and connected to each other with the help of water pressure (hydraulic simulation). In the Bad Urach heat exchanger temperatures can reach 170 °C.

The plant in Bad Urach will be the first geothermal power station in Europe which generates electricity from the depths of the earth with the help of HDR technology. In the initial stage, the plant will have an electrical capacity of about 1,250 kW which is sufficient to supply about 2,000 households. Additional boreholes, an extended joints system, and larger volumes of circulating water will allow capacity to be further increased.