How can water be used as a climate-friendly heat source? This question will be addressed at the Faculty of Supply Engineering – Energy, Environment, Facility Management's symposium on 8 May 2026 in the auditorium on Salzdahlumer Straße at the Ostfalia Campus Wolfenbüttel. Under the title "Heat from water", the focus will be on the thermal utilisation of groundwater, drinking water, river water, lake water, fjord water and wastewater.
Topic has gained in importance
Oliver Büchel, Dean of the Faculty, emphasised: "The fact that so many participants have turned up shows that the topic of heat from water has become increasingly important in science and practice." Water may be inconspicuous, but its physical and chemical properties mean that it has great potential for a climate-neutral heat supply.
Students at the faculty, such as Ole Mertins (21), agree. He says: "Germany is facing a transformation and there are still many untapped opportunities in water as a resource. What interests me most about using water to generate heat is the associated cooling and its effects on biotopes and the organisms that live there."
Great opportunity for dialogue
Student Tim Langer (21) is delighted to have the opportunity to exchange ideas with experts from local authorities, engineering offices and research institutions at the conference. "I'm particularly interested in the topic of heat from wastewater, which is covered in the first lecture." In it, Dr Hans-Otto Weusthoff from Stadtentwässerung Hannover will present heat recovery in two large sewage treatment plants.
Weusthoff: "We can generate electricity from digester gas. We do this in Herrenhausen with an efficiency of 85 per cent. This produces so much heat that we can completely cover our own heat requirements." However, the heat from the thermal utilisation of around 56,000 tonnes of sewage sludge per year is also fed into the district heating network.
Heat recovery from drinking water
However, the conference is not just about solutions, but also about weighing up the options. Because not every approach comes without challenges. For example, Dr Beate Stawiarski from the DVGW's Northern Regional Group will discuss the potential risks of generating heat from drinking water. This form of heat generation is necessary in order to achieve the climate targets. Stawiarski explains the results of a study, according to which the risk of contamination can be categorised as low.
Higher-level perspectives will also come into focus on "Utilities Day". Dipl.-Ing. Christian Seidel (TU Braunschweig) will talk about the potential of rivers and lakes for supplying heat to entire cities and how such approaches can be integrated into existing infrastructures. Charlotte Stegel (21) was particularly interested in this topic. She says: "I come from Bremen and there is a project there."
The focus is on practical benefits
For the energy and building services engineering student, the conference offers the opportunity to learn about current developments and link them to her own professional practice. "Heat from water is a highly topical issue that also affects my day-to-day work. And of course I want to keep up to date with the latest developments and projects," she says, and is not the only one who sees the conference as a direct link to her own future.
This practical relevance is also emphasised by conference director Prof. Dr.-Ing. Lars Kühl, who heads the Institute for Energy-Optimised Systems (EOS), which has been organising the event for many years. He summarises the aim as follows: "At the end, we will have an overview of the technical possibilities and the benefits that heat extraction from water can have."
