G.E.O.S. now also on the job for 525 kV connection systems for offshore wind power

G.E.O.S. has been commissioned by grid operator TenneT with planning works for the land cable sections of the NOR-9-3 and NOR-12-1* wind power plants - Planned total capacity of 4 gigawatts

The NOR-9-3 and NOR-12-1* systems are part of the 2035 grid development plan confirmed by the Federal Network Agency. The submarine cable routes run from the north across the North Sea island of Baltrum and arrive on the mainland in the area of Dornumersiel (West of Bremerhaven). This is where the planning section for which G.E.O.S. is responsible begins. Over a distance of about 100 kilometres each, the land cable section leads to the grid connection point, which is located at the site of the former Unterweser nuclear power plant. The regional planning procedure will be completed by the end of 2022, which means that several other variants will have to be planned by that time.

NOR-9-3 and NOR-12-1 will be designed in direct current technology at a voltage level of 525 kilovolts for a transmission capacity of 2 gigawatts each. Thus, the planned transmission capacity will be twice as large as the grid connection systems for offshore wind farms that have been realised in Germany so far. The cable systems will be designed as a bipole with a metallic return conductor. This means that three cable strands are installed per system.

NOR-9-3 and NOR-12-1 are the first German projects to be part of TenneT's transnational innovative 2GW programme. Under this programme, at least nine offshore grid connection systems with this high transmission capacity are to be installed in Germany and the Netherlands by 2030.

* According to the current draft of the area development plan of the Federal Maritime and Hydrographic Agency.


G.E.O.S. takes over planning works for the land cable section

The scope of work for G.E.O.S. includes the full technical approval planning, the necessary steps before, during and after the approval of the plan as well as the project coordination. In the course of the basic investigation, the scope of services commissioned includes, among other things, a preliminary subsoil investigation and surveying work. Engineers from the branches in Halsbrücke, Chemnitz and Lehrte are involved in the realisation of the contract. G.E.O.S. is supported by an engineering company from Grimma (Weishaupt Planungen GmbH).

The schedule envisages that the planning approval applications will be submitted in the first quarter of 2024. Decisions are then expected in the second quarter of 2025.

Having assisted TenneT with a large number of land cable projects in Schleswig-Holstein, G.E.O.S. is now extending its planning activities to the federal state of Lower Saxony with this project. This means that G.E.O.S. continues to be significantly involved in the development of grid expansion in the German North Sea.