Modelling of urban excess heat use in district heating systems

Use of low-temperature heat sources in district heating (DH) systems is gaining attention as a climate mitigation measure. Urban excess heat (UEH) from data centres, metro stations, sewage systems and service sector buildings’ cooling system belongs to these sources. The use of UEH affects energy supply systems and system costs. We analyse the long-term system impacts of utilizing the four UEH sources through dynamic modelling of the energy systems. The study draws on data from real cases in four cities and addresses local conditions. The results show that UEH utilization can contribute to increased competitiveness of DH compared to individual heating. The system benefits are larger if UEH replaces boilers in DH system and/or in buildings.