Heating and cooling with energy from wastewater are possible in any building with a power requirement of around 50 kW or more. That is around 15 accommodation units. The largest system constructed to date has a heat extraction rate of 2.1 MW and supplies a district with over 450 accommodation units plus commercial users. Commercial buildings are also easily heated and cooled using wastewater energy. The aim is that energy from wastewater will reach a temperature of 35 to 55 °C using heat pump technology. However, there are now also many projects when energy is stored at a higher temperature. It is always a question of competition and the next best option. Wastewater heat is also particularly suitable for storage in local authority or municipal heat networks.
