Heat from sump water: Heating seven municipal buildings

The sump water drained from the Hambach open-pit mine flows past the obsolete local heating network for the city of Bergheim into the River Erft. When the heat generators and network needed to be updated, Stadtwerke Bergheim municipal utilities in cooperation with RWE Power found an innovative solution for providing seven municipal buildings with climate-friendly heat.

Stadtwerke Bergheim municipal utilities are the first: The supplier has implemented the first municipal project for space heating using sump water from an open-pit mine. Sump water is groundwater that is pumped up for coal production in open-pit mining. By extracting water at temperatures of up to 26 °C, which is made available free of charge by the energy provider RWE, not only have the municipal utilities been given access to a climate-friendly, economical and reliable heat source. The local heating network that was in need of renovation has also been updated. Further expansion of the network will be pursued...

Engine for progress:

  • efficient, economical and environmentally friendly use of local heat
  • a reduction in CO2 emissions of 37 per cent
  • heat supply for seven municipal buildings
  • a pioneering role for other open-pit mining regions

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Photo: Stadtwerke Bergheim

In April 2014, the Managing Director of Stadtwerke Bergheim municipal utilities, Volker Mießeler, together with District Administrator Michael Kreuzberg, Mayor Mary Pfordt and RWE Lignite Planner Lars Kulik (from left to right) started work on the new central heating station that converts heat from sump water for use in public buildings.

And this is how the sump water system works

A heat pump recovers the heat energy from the sump water and contributes to meeting the base-load and medium-load requirements of seven municipal buildings: Three sports halls, three schools and the District Administration Centre for Rhine-Erft. The heat pump is supplied with power via a CHP unit, which also contributes to supplying the basic heat requirements of the buildings.
Peak demand is still covered using natural gas. In addition, two heat storage units were installed, which store heat when there is limited demand.

More than one third of CO2 is saved, a model project for open-pit mining regions

The balance is clear to see: The novel heating supply concept reduces fuel consumption by 30 per cent and CO2 emissions by around 37 per cent or 740 tonnes per year. The innovative and economical solution allows the building to be jointly supplied based on local heat sources. The concept is of interest to many similar open-pit mining regions and demonstrates how one can incorporate resource efficiency into public planning, thus making a contribution to climate protection.

Photo: Stadtwerke Bergheim

"At Stadtwerke Bergheim GmbH, not only do we understand the motto "ENERGY FROM BERGHEIM FOR BERGHEIM" to mean the advancement of wind and solar energy, but also the evaluation and improvement of existing systems through the use of innovative technologies." (Bild: Stadtwerke Bergheim)

Volker Mießeler, Managing Director Stadtwerke Bergheim

Partners and sponsors

  • Stadtwerke Bergheim
  • RWE Power AG
  • Ministerium für Klimaschutz, Umwelt, Landwirtschaft, Natur- und Verbraucherschutz (MKULNV)