Cascade

Low temperature district heating networks can very effectively utilize renewable heat sources such as solar or geothermal energy, ambient heat or low temperature waste heat. However, the vast majority of urban district heating networks operate on relatively high temperatures. The high-temperature mode of operation has a certain robustness and high-temperature networks cannot be easily transformed into low-temperature networks, for example due to the characteristics of the building stock, the requirement of transporting sufficient amounts of energy with the given capacities and high temperature heat e.g. from waste incineration. CASCADE investigates an alternative approach: the integration of low-temperature district heating networks into the return line of an existing large urban district heating network, thus creating a “sub low-temperature district heating network”. This can be a key enabler for the decarbonization of urban district heating networks by enabling an efficient utilization of local energy sources and have the potential to reduce substantially the overall network temperatures.