Dortmunder Energie- und Wasserversorgung GmbH(DEW21), the energy and water supply company of the German city of Dortmund,  is improving the supply of climate-friendly heating in downtown Dortmund by restructuring the district heat infrastructure and changing the feed-in system.

The outdated steam grid is being replaced by a modern hot water grid with lower heat loss. The resulting new grid in the city center will then be connected with the existing hot water grid in Dortmund’s Nordstadt district and a new connection which will be constructed to Dortmund’s Lindenhorst district.

In future, DEW21 will increasingly use exhaust heat from the carbon black production facilities of Deutsche Gasrusswerke (DGW), and thus successively phase out the supply of gas-based heat from Dortmund power station. Replacing the supply of gas-based heat by industrial exhaust heat means that about 45,000 tons of CO₂ can be saved per year.

To safeguard the supply of heat, three decentralized energy plants will be installed which are equipped with heat-and-power installations, gas boilers and power-to-heat installations. During the alteration and construction phase these plants will serve to ensure the interim supply of heat to customers. When the alteration work is complete, these energy plants will serve to cover peak consumption periods and to offer a back-up solution to ensure the reliability of the supply of heat.

Up to 2023 the alteration work in downtown Dortmund is due to be carried out successively in the urban districts. The progress of the construction work and the degree of implementation are dependent on the award of grants. Converting an existing supply infrastructure on this scale in an urban setting automatically involves major alteration work in a densely developed urban infrastructure.