At Groß Schönebeck, a location in the North-German Basin, Northeast of Berlin, where a geothermal borehole doublet has successfully been hydraulically stimulated, the proof of concept of a sustainable production and injection of thermal waters from deep sedimentary geothermal reservoirs shall exemplary be led. This confirmation constitutes the prerequisite for a positive classification of the North German Basin as region with a possible domestic economical contribution for the geothermal power supply of the future.