State of knowledge about the risks, impacts and potential inconveniences associated with deep geothermal


Deep geothermal is a renewable and non-intermittent source of energy that can contribute to the global transition towards a lower emission of carbon and less greenhouse emitting energy mix. Only a small share of the world's geothermal potential is being exploited today and many countries, including France, have included in their objectives an accelerated development in this area for the coming decades.

Like any industrial activity, deep geothermal drilling is accompanied with potential inconveniences and possible risks for people and the environment, which must be clearly identified and controlled in order to make this industry fully compatible with the expectations and the needs of the citizens, especially those living near such facilities. In past years, some concerns have been expressed by local authorities regarding the development of deep geothermal projects, particularly in the field of high temperature, based on the risks associated with such underground operations.

This report is intended as a scientific and objective contribution to this matter. It aims to present, in a factual and practical manner, the current knowledge about the risks, impacts and potential inconveniences associated with deep geothermal. In addition to the scientific literature, it is based on the feedback from incidents or accidents already recorded in this field. It also capitalizes on INERIS's expertise in the field of risks related to other sectors, such as oil and gas wells, to provide a larger perspective of deep geothermal technologies.

The main findings from this study are provided in the synthesis chapter at the end of the document. The reader will specifically find a global and comparative analysis of all risks, impacts or potential inconveniences linked to this sector.

Given the large amount of work published in the field of deep geothermal energy, whether in the fields of research or engineering, the authors do not claim to have exhausted this subject. They have tried to cover the available sources of information in a way that gives the benevolent reader what they consider to be a relatively comprehensive overview of the main safety and environmental issues, associated with this industry