Geothermal energy is increasingly contributing to the power supply worldwide. Iceland is world-leader in expanding development of geothermal utilization: In recent years, the annual power supply there doubled to more than 500 MW alone in the supply of electricity. Germany also has seen a dynamic development: More than 100 MW of heat currently is being provided through geothermal energy.

In Travale, Italy, a team of European scientists has localized geothermal reservoirs that offer energy potential comparable to that of 1,000 wind power plants. This is one of the results presented at the final international conference of the project I-GET (Integrated Geophysical Exploration Technologies for deep fractured geothermal systems) in Potsdam, Germany. Seven European nations participated in the project to develop cutting-edge methods with which potential geothermal reservoirs can be safely explored and directly tapped.

“The new methods deliver important decision-support for the selection of sites for future geothermal projects. With this, we can considerably reduce the risk of expensive mis-drills,” explains Dr. Ernst Huenges, head of geothermal research at the host institute GFZ, German Research Centre for Geosciences.  

The newly developed approaches have been tested at four geothermal locations with different conditions. High-temperature reservoirs have been examined in Travale/Italien (metamorphic rocks) and in Hengill/Island (volcanic rocks). Scientists also are exploring two deposits with medium-temperature in deep sediment rocks in Groß-Schönebeck/Germany and Skierniewice/Poland. The methodology is based on the measurement of seismic velocities and electrical conductivity underground, which deliver information on the rock-physical characteristics at depth. In addition to performing borehole measurements and rock-analysis, different methods have been combined.  

I-GET experiments have been carried out using a case study at the GFZ research borehole at Groß Schönebeck, northwest of Berlin. There, extensive data from experimental investigations conducted at the in-situ geothermal laboratory at Groß Schönebeck already are available. The geological conditions of the North German Basin are representative for other parts of central Europe, therefore, research results are of high interest beyond Germany's borders. In fact, the implications of the results of I-GET would be felt worldwide. Experts from Indonesia, New Zealand, Australia, Japan and the United States also participated in the project. In total, there were 120 scientists and industry representatives from the 20 countries.  

“Reliable geothermal technologies are in demand worldwide. Even countries with a long experience in geothermal energy such as Indonesia and New Zealand are interested in the results acquired in I-GET,” says Dr. Ernst Huenges. The GFZ continuing its geothermal research and currently is establishing an International Centre for Geothermal Research, which, in particular, will carry out application-oriented large-scale projects on a national and international level.