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.
