Over 50% of the world’s energy demand is used for heating and cooling, including water heating. In households, the percentage is as high as 73% of total energy consumption. To date, almost exclusively CO2-critical energy sources have been used for this purpose.

The so far largely unused wastewater is available as a renewable energy source all year round, around the clock. The temperature in the sewer is between 12 and 18 °C throughout the year and is thus higher than the temperature of outside air, geothermal energy or groundwater, even in winter. If a farm is located nearby, the temperature of the wastewater can rise up to 30 degrees.

Studies show that up to 25 % of the required heating/cooling demand in buildings can be covered by wastewater as an energy source. This makes an important contribution to the decarbonization of the heating sector.

The technology for generating energy from wastewater is simple and proven. At its heart are innovative heat exchangers that extract energy from wastewater and special wastewater heat pumps that harness the energy for heating and cooling larger buildings. In summer, wastewater energy systems can also be used to cool rooms. In this case, the heat pump acts as a chiller in a “reverse” manner.

Essential requirements are:
Sufficiently large sewer, DN 400 or larger
Available wastewater volume > 10 l/s
Temperature > 8°C
Proximity of consumer to sewer (depending on temperature level in sewer)
max. distance 900 m
Demand for heating load/cooling load > 50kW
Coordination with or approval of the sewer operator