Paper short abstract:

High-temperature geothermal energy is a pioneering case of deep-rock geoengineering that emerged in the 1980s. We follow the confrontation between human attempts at structuring new productive 'strata' and terrestrial intensities that possess their own dynamics.

Paper long abstract:

This contribution looks at the history of high-temperature geothermal energy (HTG), a pioneering case of geoengineering that emerged in response to the oil crisis in the 1980s. GHT aims at creating geothermal "loops" in the deep underground, thanks to the collaboration of various engineering fields (oil fracking, nuclear waste burial). The operation seeks to passage open passages in the deep rock by fracturing it, and to create circulations that allow fluids to be injected and the high temperatures of the deep rock to be recovered. It takes us from the concept of High Dry Rock [HDR], which originated in Los Alamos in the 1970s-80s, to the later Enhanced geothermal system [EGS], in Europe in the 1980s.

We follow the ups and downs, but also the international structuring of this technology and its transformations in the face of the failing response of the successive sites (anomalies, basement outcrops) to which it is applied. The inconsistencies between the scientific vision of and experience with the (sites) deep rock prompt disciplinary shifts (solid mechanics, geology, hydrogeology) and a further exploration of the complexity of underground circulations, opening up to geological knowledge.

The analysis takes a "political geology" approach, and questions the way in which humans articulate themselves with terrestrial intensities that possess their own dynamics (Clark, Neyrat). It questions the possibility of knowledge and power over these entities, and the way in which their materiality challenges both scientific visions and the ambition to constitute new productive 'strata' (Clark; Yusoff).