As part of the research colloquium for final theses, doctoral and habiliation candidates, we cordially invite you on Tuesday, 16.12.2025 at 15:00 in room 3716 (Mönchebergstr. 7). We are pleased to announce the lectures by Dipl.-Ing. Christian Seidel and Dr.-Ing Lars Ostermann from the Regenerative Energies working group at the Institute of Statics and Dynamics at TU Braunschweig. The titles are

"Heat recovery from flowing waters – investigation of the potential for Germany and in the 80 major cities on the basis of level-based flowing water models"

and

"Functional principles and possible applications of large heat pumps for the recovery of heat from flowing waters in local and district heating networks"

We look forward to seeing you there!

Abstract "Heat recovery from watercourses – Investigation of the potential for Germany and in the 80 major cities on the basis of level-based watercourse models"

With over 400,000 km of watercourse network and more than 185 billion m³ of average annual discharge, Germany's watercourses cover a large area and have great potential for heat recovery. Current studies by the Institute for Statics and Dynamics at the TU Braunschweig show that with a temperature reduction of 2 K, a heat potential of 430.8 to 861.5 TWh/a can be tapped in Germany, which corresponds to 36 % of the final energy demand, 64 % of the heat demand and 94 % of the heat demand in the low temperature range up to 100 °C. The stream heat potential in the 80 major cities in Germany was calculated on the basis of level-based stream models. As the investigations show, 41 large cities can cover their entire space heating demand and 58 large cities can cover at least 50 % of their demand from watercourses. The best way to generate heat from running water is via hydropower plants. For example, 33 large cities alone could generate all of their space heating requirements for households from the expansion flow of the hydropower plants in operation, as the studies carried out in the 80 large cities in Germany have shown.

Abstract "Functional principles and possible applications of large heat pumps for the recovery of flow heat in local and district heating networks"

Large-scale heat pumps are a promising technology for utilizing the heat of rivers and streams for the heat transition. They extract the thermal energy from the watercourses via one or more heat exchangers and raise the temperature level in the heating network using a thermodynamic cycle so that the heat obtained can be fed into the local and district heating networks. With output ranges of several megawatts, they are able to supply entire neighborhoods or even cities with heat. Typical areas of application are municipal local and district heating networks, neighborhoods and industrial sites with requirements for space heating, hot water and process heat up to 100 °C. Successfully implemented practical examples of the use of flowing water heat can be found in Lemgo, Rosenheim and Mannheim, among others. The heat pump technology used here has been used successfully and sustainably since the 1930s to generate heat from running water. The coolants play a key role in the design of the heat pump and influence not only the possible temperature ranges but also the effectiveness of heat recovery as well as the source temperature and the flow and return temperature of the heating networks. In addition to the costs of expanding the heating network, the cost-effectiveness of the technology is also an important aspect in the implementation of large heat pumps for recovering heat from flowing water.