Development of EGS in the Upper Rhine Valley: from the Soultz EGS pilot project to industrial projects
Dr Albert Genter, Geologist, ES Group, Strasbourg, France
The Upper Rhine Valley is one of the most active areas in terms of deep geothermal project development in Europe. In the 80’, this area was characterized by the failure of deep geothermal projects for exploiting the matrix permeability of deep sandstones in Strasbourg (Cronenbourg project) and the temporary stop of the Bruchsal project exploiting deep sandstones close to Karlsruhe. Thus, the geothermal revival of the Upper Rhine Valley was mainly possible thanks to the French-German pioneer teams which initiated the European geothermal project located at Soultz-sous-Forêts, 50 km NE of Strasbourg. Starting with a typical Hot Dry Rock (HDR) concept at the end of 90’, this pilot project explored deep crystalline basement, reputed impermeable, till 5 km depth through various deep drilling operations, hydraulic and chemical stimulations and hydraulic circulations. Then, it was demonstrated that some geothermal energy could be extracted from the basement, and a first binary power plant was erected. However, as some natural permeability was identified, even in the deepest drillholes, the experimental concept at Soultz significantly evolved from HDR to EGS, meaning Enhanced Geothermal System or Engineered Geothermal System.
In connection to the Soultz learning curve that proved the initial natural permeability can be enhanced in basement like reservoir, a series of industrial projects started on both the German and French sides of the Upper Rhine Valley. At Landau and Insheim, located in the Rhine-Palatinate about 50 km from Soultz, two binary power plants were built between 2007 and 2012 by German industry and are now operating with varying success. The Bruchsal project was redesigned, and a binary plant was also built at the same period and is now operating.
On the French side, a purely thermal project, driven by the ES Group, started in 2011 at Rittershoffen located at less than 10 km from Soultz. Two deep wells were successfully drilled into the basement and are able to produce or reinject expected flowrate of 70L/s and temperature higher than 160°C for feeding a bio-refinery located 15 km from the drill site. The construction of the surface pipe system between the factory and the drill pad is ongoing, and this project will be operational at the beginning of 2016 producing 24MWth.
In the Upper Rhine Valley, several industrial companies (oil companies, energy companies, industrial consortium, public-private joint venture) are looking for electrical or cogeneration projects. For ES group, the Illkirch project located in the suburb of Strasbourg will be the next deep geothermal project developed. In parallel, a new power plant will be erected at Soultz in 2016.
The presentation will provide results and detailed examples about development of deep geothermal projects located in the Upper Rhine Valley.