The 380kV line from Wahle in the German federal state of Lower Saxony to Mecklar in the state of Hesse is one of the underground cable pilot projects laid down in the German Power Grid Expansion Act (Gesetz zum Ausbau von Energieleitungen – EnLAG). For the construction of the line, TSCNET shareholder TenneT, the Dutch-German transmission system operator (TSO), is testing a new ploughing technology for laying empty conduits, into which the three-phase underground cables will later be inserted.
The so-called multiple ploughing method was presented today in the Lower Saxony village of Wartjenstedt (near Hildesheim) to representatives from politics, authorities, associations and the media, as well as farmers and land users. At a test track of around 200 metres, the cable plough specialist company Frank Föckersperger and TenneT demonstrated how the specially developed cable plough can be used for the Wahle-Mecklar project.
Olaf Lies, Minister for the Environment, Energy, Construction and Climate Protection of Lower Saxony, was impressed by the demonstration: “The test in Wartjenstedt shows that when installing underground cables, it is possible to minimise interference with the existing soil structure and reduce construction costs and time by using new laying techniques.” TenneT Managing Director Tim Meyerjürgens complements: “TenneT aims to introduce the multiple ploughing method to the state-of-the-art technology to accelerate the grid extension. After about three years of research, it is a great success to test this important innovation on site for Germany’s longest 380kV underground cable section.”
If the test phase for the plough, which is to last until mid-October 2019, is successful, TenneT intends to use the new method on suitable sections of the Wahle-Mecklar project on a trial basis in spring 2020. Depending on the test results and the respective local conditions, TenneT expects a significantly reduced construction time for underground cable lines when using the multiple plough. Since experience with cable ploughing technology has so far only been available for lower voltage levels, TenneT is once again doing pioneering work to design the energy transition grid and establish new technologies.