Until the end of the 1990s, public and private buildings in Mayen (Rhineland-Palatinate) were heated by distributed facilities based on conventional fuels like fuel oil and natural gas.

A short distance from the city the WEIG-Karton company operates a big paper mill. The mill's production processes give rise to large quantities of waste heat. In order to utilize this waste heat as heating energy, Moritz J. Weig GmbH & Co. KG, today's STEAG New Energies as district heating specialist, and the Mayen municipal utility joined forces.

Their goal was to realize the supply of district heating to the city solely using waste heat from the paper mill. This concept has model character in Rhineland-Palatinate because previously unused energy now is being put to meaningful use on a large scale. As a result, the emissions of harmful carbon dioxide in Mayen have been substantially reduced and air quality in the region improved. The annual CO2 reduction comes to around 5,400 metric tons.

For the project "District Heating Supply in Mayen", in September 2014 STEAG New Energies and the City of Mayen received the Tandem Award for exemplary cooperation projects with enterprises, as part of the "SME-friendly Communities 2014" competition of the State of Rhineland-Palatinate.