ABSTRACT
The thermal activation of foundation elements through the installation of absorbers in components being in contact with the underground has become state-of-the-art. A new approach involves the thermal activation of sewers as a part of the urban hydraulic infrastructure. These so called ´hybrid sewers´ enable energy extraction or storage from both the inner sewer climate and the subsoil in which the sewer is embedded. The wastewater flow continuously supplies thermal energy, so that a higher thermal energy can be obtained than from usual activated foundation elements. Consequently, the system is base load-capable and is therefore suitable as the basic system of a regenerative heating network. The thermal performance of hybrid sewers, previously unexplored, has now been validated using numerical simulations and measurements.
