Geothermal resources for power production in Germany

Abstract

Organic Rankine and Kalina cycle technique allow efficient electric power production at temperatures
as low as 100 ?C and makes geothermal power production attractive even for countries
like Germany lacking high enthalpy-resources at shallow depth. In a study performed in
2002 the geothermal resources for geothermal power production in Germany were estimated.
Three types of reservoirs were considered: hot water aquifers, faults and crystalline rocks with
temperatures above 100 ?C and at depths down to 7000 m. Assuming realistic values for the
recovery factor and the efficiency the accessible electric energy was calculated. The electrical
energy was estimated to 10 EJ (1 EJ = 1018 J) for the hot water aquifers, to 45 EJ for deep
reaching faults, and to 1100 EJ for crystalline rock. This corresponds to an annual power consumption
of 2 EJ for Germany. These huge resources justify further F&E developments especially
for the exploitation of heat from faults and crystalline rocks.