Sewage treatment plants are among the largest municipal energy consumers. At the same time, sewage treatment plants are able to provide energy because they produce biogas independently. The progressing energy turnaround poses unsolved problems for fossil fuels in particular. According to the current state of technology, the demand for crude oil and natural gas can be replaced in large quantities but not completely by alternatives such as electricity and heat. However, the residual non-substitutable demand for hydrocarbons far exceeds the capacities of current technology (source: Fraunhofer IWES). Sewage treatment plants as an existing and ubiquitous infrastructure worldwide, which are also characterized by their similarity, could make a valuable contribution in this area in the future. The wastewater associations have not yet recognised this responsibility, as they rightly see their main responsibility to date in the quality of wastewater treatment. However, by increasing energy efficiency, i.e. reducing own demand and increasing gas production, sewage treatment plants could increasingly do justice to this task. At the same time, however, effluent values and total operating costs are to be optimised. The Interreg region is very similar here in terms of comparable infrastructure, legal and ecological guidelines and wastewater characteristics. Thus, the transfer of technology and methods is theoretically easy to implement and makes sense, since in past projects (EnerWater) geographical differences and overall great potentials were also identified.