H-BRS student calculates efficiency of river heat pumps at low water levels

In view of the rise in global temperatures, the use of renewable energies is more important than ever. In 2023, only just under a fifth of heat in Germany came from renewable sources. Electric flow heat pumps could help to increase this proportion. They work in a similar way to heat pumps in buildings. The heat is not extracted from the air, but from a small amount of river water. The temperature of the pumped water is then increased by a thermodynamic process. The heated liquid can then be fed into the heating system of a building, for example. Once the heat has been released, the cooled water is returned to the river. The water does not come into contact with the refrigerant or other chemical substances.

River heat pumps are particularly effective in regions with stable water levels and temperatures. This is where Antonius Ashadhiarto Wiryanto's scientific work comes in. In his Bachelor's thesis at H-BRS, the economics student calculated whether river heat pumps also work efficiently at low water levels and what impact this could have on the water. His analysis of a section of the Rhine near Cologne was based on a river heat pump that was put into operation on the Rhine near Mannheim in October 2023.

“The use of three river heat pumps with a total output of around 60 megawatts could supply around 10,000 households in Cologne for the next 30 years.