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  • STEAG builds the heating supply system of the future

    In order for the energy transition to succeed, there is a need to restructure not only electricity production, but also heat generation and distribution. District heating is a central component in this process. With the construction of the Eastern Line in Essen, STEAG is demonstrating how heat supply can be designed for the future.

    This project definitely belongs to the 'ambitious' category: Six kilometers of district heating pipelines will be laid at depths of up to 2.50 meters across the east of the second largest city in the Ruhr area. Nine districts of Essen are to be fully or partially connected in this way by the end of 2020. 
    STEAG Fernwärme Essen GmbH & Co. KG, a joint venture of STEAG Fernwärme GmbH and Stadtwerke Essen AG, is investing around 20 million euros in the Eastern Line project. And last but not least: "With the expansion of the distribution network, we will achieve a prospective reduction in the emissions of environmentally harmful CO2 in the east of the city by up to 30 percent.

    Residents in the districts of Frillendorf, Kray, Südostviertel, Huttrop, Bergerhausen, Rüttenscheid, Stadtwald, Margarethenhöhe and Bredeney will then be able to take advantage of the climate-friendly, safe and convenient heat supply and support the local transformation in the heating sector," says Markus Manderfeld, Managing Director of STEAG Fernwärme Essen. The Eastern Line is also a challenge in terms of planning and construction. In order to lay the 12,000 meters of pipes - 6,000 meters for the hot water supply to the customers and 6,000 meters for the return to the heating plant - with a diameter of 80 centimeters each, six kilometers of streets literally have to be torn open in Essen's city Center.

    "By expanding the distribution network, we will reduce emissions of environmentally harmful CO2 in the east of the city by up to 30 percent in the Long term."

    Markus Manderfeld, Managing Director of STEAG Fernwärme Essen

    In order to keep the inconvenience for local residents as well as commuter and delivery traffic as low as possible, the managers at STEAG Fernwärme Essen have divided the entire line into three construction phases, otherwise known as construction lots. “We started with lots 1 and 3 in June and August respectively, and since the beginning of October we have also been working on lot 2,” explains project manager Georg Röttgers, who shares the site management for the Eastern Line project with his colleague Hartwig Wolowski. “The plan to work on three project phases in parallel is an ambitious one. The first two sections are on schedule, and we expect that to be the case in the third section as well.”

    In spite of careful planning and coordination with the municipal authorities, the speed at which the construction measures are actually carried out always becomes apparent at the construction site. “There’s a nice saying in the Ruhr district that still comes from the mining industry: ‘It’s always dark before the pickaxe strikes’,” says the STEAG supply systems engineer, who has spent every day on the construction sites since the project began. “And that also applies here: No-one can say exactly what there is beneath the asphalt. We have to be flexible and sometimes rethink.”

    In sections up to 250 meters long, three civil engineering companies commissioned by STEAG are digging the trenches for the new district heating pipes. These are then stabilized with special support walls. “This is a kind of travelling construction site,” Georg Röttgers explains. “If we were to lay the pipelines on a greenfield site, we would be able to deploy many more construction crews and would also make much faster progress. But we have to take the circumstances into account. In Essen, traffic is already heavy anyway. And there is a limit to what is reasonable.”

    In the trenches, which are 3 meters wide and up to 2.50 meters deep, the 12 meter long district heating pipes are lined up piece by piece by employees of the pipe construction company commissioned by STEAG and then joined together by the vertical-down welding process. Inside, there is a steel pipe with a diameter of 60 centimeters which is encased in 10 centimeter thick polyurethane insulation. “This is all purely manual work, carried out by specialists with many years of experience,” says Georg Röttgers. “It will last for at least 50 years, and probably even 30 years longer.” In addition, wires will be installed for a leakage detection system. This system makes it possible to locate potential leaks in the pipeline, caused for example as a result of external damage during road construction work, to within one meter.


    “In terms of its significance for the heating transition, district heating is active climate protection, and with the Eastern Line in Essen we are virtually laying the backbone for the future district heating concept of STEAG Fernwärme Essen.”

    Georg Röttgers, Project Manager

    In the Ruhr district city, which was awarded the title “Green Capital of Europe” in 2018, the municipal administration is adopting a benevolent approach to the construction of the Eastern Line despite the temporary restrictions in the inner city: “With the expansion of district heating, we are ensuring a better quality of life, because the use of climate-friendly district heating significantly improves the carbon footprint of our city,” says Essen’s Mayor Thomas Kufen. “With an eye to this common goal –saving around 11,000 metric tons of CO2 per year – we are supporting the complex construction work.

    And the expansion of the district heating network in Essen is also seen by the State Government of North Rhine-Westphalia as a significant contribution to the heating transition and climate protection in the state. For this reason, the construction of the Eastern Line will be subsidized with eight million euros from the European Regional Development Fund (ERDF), which will be awarded by the State of North Rhine-Westphalia as part of the ‘progres.nrw’ funding program – a contribution with a long-term effect, because the Eastern Line marks the beginning of the heating transition in Essen. Over the next 15 years, STEAG Fernwärme Essen’s district heating network is to be extended to a total length of 90 kilometers. Via the extended pipeline network, as calculations show, it will then be possible to distribute climate-friendly district heating to up to 20,000 additional households.

    In this way, STEAG is pushing ahead with a development in the company’s headquarter city that is urgently needed to achieve the goals that the German government has set in its ‘climate package’. For up to now, the energy transition has almost exclusively addressed the electricity sector, although that only accounts for about 20 percent of final energy consumption, while heat generation accounts for about half of it. District heating networks such as the one in Essen can significantly reduce the emission of climate-damaging CO2, which is produced, for example, by old heating systems. In this respect, district heating is an important building block in combating climate change – especially since more than 90 percent of the heating energy is generated using the environmentally friendly cogeneration process.

    “In terms of its significance for the heating transition, district heating is active climate protection,” says Georg Röttgers, “and with the Eastern Line in Essen we are virtually laying the backbone for the future district heating concept of STEAG Fernwärme Essen.”