Study «Energy from the earth's interior: Deep geothermal energy as the energy source of the future?»
What is deep geothermal energy?
Geothermal energy is thermal energy which is generated to a large extent below the surface of the earth. Geothermal energy close to the surface is already well established, i.e. the use of thermal heat captured within 400 m of the upper surface in the form of hot water or steam is widespread in countries such as the USA, the Philippines or Italy to produce thermal heat and electricity. Deep geothermal energy (deeper than 400 m) is increasingly regarded as a source of energy for Switzerland that is theoretically boundless, renewable and low in CO2. Deep geothermal energy is divided into hydrothermal and petrothermal geothermal energy. In hydrothermal systems available deep water or steam is used, but in petrothermal systems (also known as "Enhanced Geothermal Systems" EGS) the water first has to be pumped into the rock from outside. To do that, it is injected under high pressure into artificially enlarged fissures and fractures.
Opportunities and risks of deep geothermal energy
Deep geothermal energy is promises to be a renewable, clean form of energy with a low environmental impact (no effects on biodiversity, small ecological footprint). It can deliver energy and/or electricity constantly, independently of sunshine, precipitation, wind and weather, and is a domestic source which guarantees high security of supply. In addition, it can be used both for heating and for cooling.
Petrothermal systems however are still in their infancy and present a number of technological challenges. For instance, EGS technology can cause microseismicity (small earthquakes), which makes its acceptance problematic. Harmonisation and clarification of the legal framework conditions at federal government level are therefore also required, because there are no guidelines on the ownership of geological data, which are also often difficult to access. In addition, there is currently no detailed evaluation of deep hydrothermal and petrothermal resources, or of their potential for producing heat and electricity. Because the level of knowledge is low, the financial risks are still considerable, and EGS technology remains undeveloped commercially. Investigations have also still to be done on the consequences (advantages and disadvantages) for the environment of developing deep geothermal energy.
Why conduct a TA-SWISS study on this subject?
This form of energy is also currently popular in political circles, although there are no reliable empirical findings on the challenges posed by the exploration methods. Before deep geothermal energy plants are built, there are a number of questions to be clarified (see “Aims of the study”). While there are already individual reviews of specific aspects such as technology used or acceptance, there is no comprehensive interdisciplinary analysis.
Aims of the study
The key focus points of this study are:
- Clarification of the future prospects (opportunities and risks) of deep geothermal energy
- Evaluation of deep geothermal resources and the potential of geothermal electricity production in Switzerland
- Description of the state of current exploration methods such as hydrothermal and petrothermal geothermal energy and the possibility of developing them
- Evaluation of the prospects of finding suitable resources for geothermal energy projects, drilling capacities and the cost effectiveness of geothermal energy plants (with reference to Switzerland’s energy policy strategy)
- Calculating the environmental consequences (advantages and disadvantages) of developing deep geothermal energy; e.g. CO2 savings potential, triggering of earthquakes
- Investigation of the current legal framework in Switzerland at federal, cantonal and commune level as well as at international level, inc. accessibility of geological data
- Analysis of the public perception of the technology and the examination of its possible dangers (e.g. seismic events) among the public.
The study will be conducted in 8 work packages:
- Resources: Literature analysis to estimate the potential of geothermal resources in Switzerland and updated estimation of the potential of resources
- Technology: Literature analysis and survey with experts on the status of current and projected geothermal technologies
- Economy: Cost model analysis to produce a geothermal ‘cost supply curve’ for Switzerland
- Environment: Life Cycle Impact Assessment methods to quantify the effects on human health as well as on ecosystems and quality of resources
- Risks: Literature analysis of the literature on unintentional geothermal risks, quantification of risk indicators and comparative risk assessment using the PSI ENSAD database; literature analysis on seismic risks and evaluation of their impact on geothermal potential in Switzerland; literature analysis on the risk perception of deep geothermal energy, content analysis of articles in newspapers and official documents
- Regulation: Literature analysis of the literature on the current legal situation in dealing with geothermal energy and survey with experts as well as the authorities
- Public opinion: Focus group to analyse public perception and analysis of the debate on geothermal energy in the social web
- Integration: Incorporation of results, overall assessment based on the evaluation of experts and using theMulti Criteria Decision Analysis (MCDA); formulation of recommendations for different target groups
Project begins: March 2013 | completion: Summer 2014
Results and downloads
Energy from the Earth. Deep Geothermal as a Resource for the Future? TA-SWISS Study TA/CD 62/2015, Stefan Hirschberg, Stefan Wiemer, Peter Burgherr (eds.), vdf Hochschulverlag AG, 524 Seiten, CHF 57.00 / EUR 49.80 (D)
ISBN 978-3-7281-3654-1 (Buch) / Download open access (TA 62/2015 e)
«Tiefengeothermie – Rechtslage und Empfehlungen», deutsche Übersetzung des Kapitels 7 «Legal Opinion» der Studie.
Electric energy from deep below. Abridged version of the TA-SWISS study. Centre for Technology Assessment (ed.), TA-61A/2014,
Bern, 2014 (TA 62A/2014 e)
Available at project completion
- Centre for Technology Assessment TA-SWISS
- Swiss Federal Office of Energy SFOE
- Commission for Technology and Innovation CTI
- Swiss Academy of Engineering Sciences SATW
TA-SWISS Project Supervisors
- Dr Christina Tobler, TA-SWISS. E-Mail
- Dr Stefan Hirschberg, Head of Laboratory for Energy Systems Analysis, energy research section, Paul Scherrer Institute PSI, Villigen
- Prof Dr Stefan Wiemer, Swiss Seismological Service SED, Swiss Federal Institute of Technology, Hönggerberg Campus, Zürich
- Prof Dr Dr h.c Ortwin Renn, Scientific Director and Managing Director, Dialogik, Stuttgart, Germany
- Dr Gunter Siddiqi, Swiss Federal Office of Energy SFOE, Bern, chairman of the supervisory group
- Jürg Balmer, Swiss Federal Office for Civil Protection – BABS, Bern
- Willy R. Gehrer, Siemens Schweiz AG, Electrosuisse, Zürich, SATW delegate
- Dr Monika Gisler, Unternehmen Geschichte & Entrepreneurial Risks, ETH, Zürich
- Elmar Grosse Ruse, WWF Schweiz, Zürich
- Dr Rolf Hügli, Swiss Academy of Engineering Sciences SATW, Zürich
- Dr Peter Meier, Geo-Energie Suisse AG, Zürich
- Thomas Müller, Schweizer Radio DRS, Basel
- Dr Kurt Nyffenegger, Groundwater & Water Supply Section, WWEA, Zürich
- Prof Dr Etienne Poltier, Lausanne Faculty of Law, University of Lausanne
- Prof Katharina Prelicz-Huber, Vpod, Zürich
- Dr Berthold Schmidt, KTI Delegate, Bern
- Jörg Uhde, Axpo Power AG | Neue Energien, Glattbrugg
- Dr Pascal Vinard, BKW Energie AG
- Dr Felix Würsten, science journalist, Zürich
- Dr Roland Wyss, GEOTHERMIE.CH, Swiss Society for Geothermal Energy SVG - SSG, Frauenfeld
- Olivier Zingg, Geo-Energie Suisse AG, Zürich
Website of the Swiss Federal Office of Energy SFOE «Geothermie»: www.bfe.admin.ch/php/modules/publikationen/stream.php?extlang=de&name=de_394691090.pdf
Report by the Office of Technology Assessment at the German Bundestag TAB (2003): «Possibilities for geothermal electricity generation in Germany»:http://www.tab-beim-bundestag.de/en/publications/reports/ab084.html
CH-3011 Bern T + 41 31 310 99 60
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The project in brief
The study will investigate the reporting of Synthetic Biology in selected print media from the German- and French-speaking parts of Switzerland. Discussions with experts should then enable any misunderstandings in conveying this newly evolving scientific discipline to be clarified.
Project: November 2012 – February 2014
Products: Code book and working report on the content analysis and the expert workshops held.
Project management: Institute of Clinical Molecular Biology at the Christian-Albrechts-University in Kiel IKMB