The overall objective of the research project is the development of a geothermal heat supply concept for urban areas using the example of a site in Berlin. The lack of interest of energy suppliers in the hydrothermal resources and heat supply in Berlin is a major reason for the lack of a geothermal heat supply concept. Aquifer heat storage can be explained by the structurally disadvantageous comparison to fossil energy sources and conventional thermal storage. High investment costs and long amortisation periods offer little incentive to develop hydrothermal supply technology or aquifer heat storage technologies. Above all, however, an existing exploration risk represents a significant investment risk, which has so far prevented the commercial development of these technologies. The objectives of the project are therefore (1) to reduce the exploration risk for aquifer heat storage facilities in the Berlin urban area by means of drilling and innovative exploration methods and (2) to provide the planning basis for efficient system integration with reliable and safe operation in the Berlin district heating supply.