E.ON Fernwärme GmbH ranks among Germany's largest district-heating utilities. The company supplies heat directly to private households, residential property management companies, municipalities as well as to industrial, commercial, and retail customers located in numerous cities in the center of Germany's Ruhr region. It also supplies five other urban areas indirectly by feeding heat into third-party distribution networks.

E.ON Fernwärme GmbH uses decentralized heat generation plants to supply local area heating in regions of North Rhine-Westphalia that are not serviced by the state's district-heating transmission infrastructure. Renewables represent a significant part of its decentralized heat generation mix.