Fonroche required to do additional test on its Vendenheim geothermal project in Alsace, France

Drilling rig on site of Vendenheim project, Alsace/ France (source: Fonroche)
Alexander Richter 26 Sep 2020

To better study potential risks in stimulation efforts, French developer Fonroche has been tasked to conduct a study before it potentially can restart work on its geothermal heat and power project in Vendenheim, Alsace/ France.

In November 2019, an earthquake north of the Eurometropolis of Strasbourg, in Alsace/ France temporarily stopped the geothermal project by French developer Fonroche.  With a concern that this could be connected to the geothermal project by the company, there is no certainty still nearly a year after it occured.

In a press release the prefecture of Bas-Rhin announced that it requires Fonroche to conduct additional tests. The company will now add coloured fluids into groundwater starting October 1 with the goal to produce a hydrogeological map and detect new tensions of the subsurface below Vendenheim.

Consequently, Fonroche cannot resume its exploitation of the heat drawn from 5,000 meters below the earth’s crust. The company had planned to install the a geothermal electricity production plant on the site of the former Reichstett refinery (in Vendenheim). The equipment was supposed to provide electricity to the equivalent of 10,000 homes and the equivalent of 26,000 homes or 70 ha of agricultural greenhouses with direct heat.

But earthquakes came as a reminder on November 12, 2019 that underground cavities did not like to be disturbed by high pressure … Water injections from the Vendenheim plant have since been suspended , pending measures to impact that seem complex to establish. The analysis of the seismic event was entrusted to the National Institute for the Industrial Environment and Risks (Ineris) and to the Bureau of Geological and Mining Research (BRGM). They worked using data from Fonroche and the School and Observatory of Sciences and Earth (Eost). However, it was not possible to link the geothermal operations of Vendenheim to the seismic activity observed that day.

All these experts proposed to the prefecture that a “map” be made of the hydrogeological compartments under Vendenheim and Reichstett. From October 1, 2020 a colored and inert material will be injected in order to better know the water circulation conditions in depth. It will be a question of checking whether tensions accumulate in the basement, which could create seismic movements.

If all these tests prove to be favourable and demonstrate that the risks are under control, industrial operation of the geothermal power plant could be considered at the end of the first half of 2021.

Source: Rue89 Strasbourg