Unlocking the Earth's heat: Safe and sustainable geothermal solutions for climate change

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Event details

Date 18.11.2024
Hour 12:0013:15
Speaker Prof. Brice Lecampion Prof. Stefan Wiemer
Location Online
Category Conferences - Seminars
Event Language English
Producing electricity 24/7 from deep geothermal resources without inducing earthquakes?
Presentey by Prof. Brice Lecampion, Head of the Geo-Energy Lab - Gaznat chair, ENAC, EPFL
Geothermal resources exist everywhere at sufficient depth (e.g. 4km+ in Switzerland). However, large fluid fluxes must be brought to the surface to produce electricity (and use the remaining heat). This requires the presence of sufficiently permeable rocks at depth. This last requirement is at odd with the fact that deeper (often crystalline) rocks are very tight.
For decades, the geothermal community has aimed at “stimulating” the pre-existing fractures of these deep rock masses via hydraulic stimulation performed at pressures sufficiently large to shear them but lower than the pressure required to propagate new fractures. This has resulted in mixed results: many projects ended inducing large earthquakes. 
 
De-risking deep geothermal energy projects: The DEEP approach
Presented by Prof. Stefan Wiemer, Chair of Seismology, ETH Zürich
Enhanced Geothermal Systems (EGS), unlike conventional hydrothermal geothermal systems, exploit geothermal resources through hydraulic stimulation that improves the permeability of the reservoir to create a heat exchanger. Induced seismicity is in EGS projects, not an undesired by-product but a necessary tool.
The art of successful EGS stimulation lies in creating an economically viable heat exchanger in the deep underground while avoiding larger and potentially damaging earthquakes. Especially in urbanised areas, deep geothermal resources can only be exploited using EGS technology if induced seismicity is adequately managed and controlled.
This talk will review the progress made in induced seismicity monitoring, forecasting, and mitigation strategies, showcasing the results of the EC GEOTHERMICA project DEEP.