Challenges of Geothermal Energy Projects
The Nov. 2017 Mw 5.5 Pohang earthquake in South Korea induced during the reservoir creation phase of a deep geothermal energy project represents a major setback and tremendous challenge to future deep geothermal energy exploitation. Enhanced Geothermal System (EGS) projects in deep crystalline rocks are especially under pressure because induced seismicity is strictly linked to permeability enhancement of the reservoir for creating an efficient heat exchanger. However, hydrothermal and geothermal systems are also challenged by induced seismicity, as the strongly felt November 2019 Strasbourg earthquake sequence documented again. Existing and upcoming geothermal projects in DEEP partner countries France, the Netherlands, Switzerland, Germany and the USA will need to present competent answers to the challenges related to induced seismicity and convincingly present more reliable procedures to assess and reduce the seismic risk. Otherwise, they will not be able to maintain their social license to operate and deep geothermal energy growth will be severely scaled down.