A project to emulate: Joint project brings sustainable heat supply for a climate-friendly future

Thanks to a collaboration between chocolate manufacturer Ritter and Stadtwerke Tübingen, a heating solution implemented in Dettenhausen in Baden-Württemberg can be seen as a best practice for the rest of Germany. Developed as a joint project, the new heating concept is efficient, sustainable, and ecological. The Dettenhausen energy center includes one of the largest solar thermal roof systems in Germany as well as a highly efficient Jenbacher combined heat and power (CHP) plant from the INNIO Group.

Sustainability

Dettenhausen is an impressive example of what is possible when companies work together constructively with the community's supply future in mind.

Ortwin Wiebecke, Managing Director of Stadtwerke Tübingen

Sustainable heating solutions are one of the major tasks that municipal energy supply companies must tackle. Dettenhausen, near Tübingen, shows how this challenge can be solved with its new energy center. The future-proof heating concept was made possible by the constructive collaboration between chocolate manufacturer Ritter and the municipal utilities company Stadtwerke Tübingen. Ritter, which is firmly rooted in the region, built one of Germany’s largest solar thermal systems on the roof of one of its warehouses. With 468 collectors on a total collector area of 2,312 square meters, it meets around 20% of Dettenhausen’s heating requirements. The rest is supplied by Stadtwerke Tübingen’s newly built energy center right next door. At the heart of the sustainable heating solution is a CHP plant, installed in 2021 from the INNIO Group with an electrical output of 999 kW and a thermal output of 1,232 kW. In addition to a Jenbacher JMS 416 GS, the plant includes two heat exchangers, which also use the thermal energy from the Jenbacher module’s exhaust gas.

999 kW

Electrical output

1,232 kW

Thermal output

0.28

Primary energy factor

1,000t

Annual CO₂ savings

Outstanding waste heat use

An additional 92 kW of thermal output is fed into a low-temperature circuit via a third heat exchanger, which serves as a heat source for a Combitherm heat pump. Another 83 kW of thermal output is available to the heat pump from the CHP plant’s waste heat, which is recovered by room coolers in the CHP room. The heat pump raises an additional 175 kW of thermal output to a higher temperature level, also making it usable. A 3,000 kW peak load boiler and two large heat storage tanks complete the system.

Numbers that speak for themselves

At commissioning, the system’s primary energy factor was already a low 0.28, meaning that throughout the entire generation chain only 0.28 kWh of primary energy was used to supply the end consumer with 1 kWh. By comparison, the primary energy factor for the current German electricity mix is 2.4. Another impressive figure: Compared to individual gas heating systems, the new heating concept in Dettenhausen saves 1,100 metric tons of CO₂ per year.

With our Jenbacher CHP plant in Dettenhausen, we are proud to contribute to a heating solution that is an example of a best practice for all of Germany.

Joachim Maier, responsible for the Jenbacher product brand’s German business at the INNIO Group