The future provision of electricity will increasingly be provided by volatile generators such as solar and wind, which means that the  provision of balancing power  will become more important. Deep geothermal energy enables the provision of electricity and heat for a base load, this arises the question whether it could in principle also be suitable for the provision of balancing power. The  GeoFlex research project  shows that, from a technical and hydrogeochemical point of view, there is nothing speaks against  the flexible operation of geothermal power-heat systems and thus balancing power can be provided without negatively affecting the district heating supply. This knowledge can be of particular importance for the future electricity market, which will be characterized by volatile electricity supply. In particular, additional flexibility elements such as  heat storage and heat pumps increase  the economic and technical potential and thus lead to behavior that is more beneficial to the system overall. In order to tap the potential and promote the expansion of flexibility options, appropriate incentives must be created under the current market situation.