Badische Stahlwerke
To District Heating Network Strasbourg
District Heating Network Kehl
The coordination effort is very high, given the many players from both countries involved. In the practical implementation, many organisational and legal issues must be solved. This in- cludes a suitable binational organisational structure. For the construction and operation of the necessary pipeline, a mu- nicipal public company was founded under French law, al- lowing foreign local authorities to participate. In this “Société d’économie mixte locale Calorie Kehl-Strasbourg” (SEML CKS), the Eurometropolis of Strasbourg has the largest share of 47 %. Smaller shares are also held by the city of Kehl (12.75 %), the region Grand Est (12.75 %), the state of Baden Württem- berg (12.75 %), and the French Banque des Territoires (CDC) (15 %). Badische Stahlwerke (BSW) also holds one share and is involved as an observer. The general director of Calorie Kehl-Strasbourg, Sabine Schimetschek, was born and raised in Germany but worked most of her professional life in France. Thus, she embodies the cross-border character of the project. Since the common goal is to start operating the system by 2027, CKS pushes the design and planning process forward. The rise in construction costs combined with increasing ener- gy prices due to the energy crisis of 2022 requires an update of the calculation of project economics. Now, an engineering company analyses the outline of the pipeline with the need to minimize construction costs and the requirements in the approval process at the same time. The initially preferred micro tunnelling minimizes the interference with existing infrastruc- ture but is the most costly solution. Therefore, alternative con- struction methods are investigated.
generation plant and the municipal waste incineration plant. This means about 60 percent of the heat is already provided by renewable or CO2-neutral energy sources. As the heat from the biomass cogeneration plant is still subject to a multi-year pur- chase obligation, the waste heat from BSW will only be able to replace a significant part of the heat produced by gas boilers in the winter months. The planned increase in annual district heating sales from the current 256 GWh to 318 GWh in 2030, however, allows for more and more waste heat use, especially in the transitional months of the year. With the expansion of Strasbourg’s heating system in mind, further sources of excess heat from the steel mill can be used. Furthermore, the opera- tor of Strasbourg’s district heating system intends to lower the operating temperature in the long run. In the coming years, the new development “Zollhofareal” will also be built in Kehl, on the southern Rhine harbour near the main station, which will also be supplied with waste heat from BSW. Accordingly, at least 70 GWh of the total available waste heat of 135 GWh can be used in the district heating networks of Strasbourg and Kehl. 7,000 households can be supplied with this energy, thus saving almost 20,000 tons of CO2 emissions per year. Kehl’s district heating system is already at a much lower temperature level. With a maximum temperature of 90 degrees, the return flow from Strasbourg can be used today as a supply for Kehl. This leads to an increased temperature spread in the transport pipe and reduced pumping energy. Should the return temperature from Strasbourg be below Ke- hl’s operating temperature in the long run, an injection system can raise the temperature level for Kehl. Implementing district heating projects using industrial waste heat is complex and costly. The cross-border dimension of the project faces additional challenges. The different languages spoken on the two sides of the Rhine and the different cultures of project management require additional effort to make the project successful.
For further information please contact: Volker Kienzlen, volker.kienzlen@ kea-bw.de
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HOTCOOL SPECIAL COLLECTION no.2 / 2023
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