Episode: Geoven geothermal project at Vendenheim

Geoven (http://www.geoven.fr) is a geothermal powerplant project led by Fonroche Géothermie now Arverne (https://arverne.earth/). The project is implemented on the site of the Rhenan Ecoparc at Vendenheim, north of Strasbourg. The geothermal powerplant produced 6 MW of electrical energy and 40 MW of thermal energy. To this end, two wells were used to draw the hot water and reinject it at more than 4000 meters deep. The two wells VDH-GT1 (https://cdgp.u-strasbg.fr/geonetwork/srv/eng/catalog.search#/metadata/VDH-GT1) and VDH-GT2 (https://cdgp.u-strasbg.fr/geonetwork/srv/eng/catalog.search#/metadata/VDH-GT2) had been drilled and some tests had been conducted (5 injectivity and productivity cycles between 02/2018 and 11/2019). A first interruption occured after a first period of seismicity (11/2019 – 01/2020, MLv=3.0 max) at Strasbourg and Vendenheim, to allow a third-party scientific expertise. During this period, the well was deepened of 450m to reach 5000m. New tests were authorized starting 10/2020, but were stopped on 28/10/2020 after a new period of seismicity with quake reaching 3.6MLv (04/12/2020). Authority decided on 07/12/2020 to definitely stop the project. Another earthquake of 3.9 ML (https://www.franceseisme.fr/donnees/intensites/2021/210626_0300/Rapport_BCSF-RENASS_2021R1_EVT210626-DPT67.pdf) occured on 26/06/2021. Authorities set up a committee of experts that delivered a first report (https://www.bas-rhin.gouv.fr/Politiques-publiques/Environnement/Geothermie/Rapport-du-comite-d-experts-cree-en-appui-a-l-administration-sur-la-boucle-geothermique-GEOVEN).