Transmission system operator Amprion has received planning approval for the offshore grid connections BalWin1 and BalWin2 within the territorial waters off Lower Saxony. Construction works on the island of Norderney are expected to begin in July. BalWin1 and BalWin2 will connect wind farms in the North Sea to the onshore transmission grid.
Amprion will install submarine cables covering approximately 155 km and 165 km respectively, alongside over 200 km of onshore underground cables for each project. The approved section spans 34 km in the coastal sea, including drilling under Norderney and the coastal dike near Hilgenriedersiel. The approval also covers cable installation between the shoreline and the 12-nautical-mile boundary.
Construction will use horizontal directional drilling (HDD), allowing protective ducts to be laid underground before the direct current cables are inserted. Work is restricted to a permitted period between July and September. Drilling will begin in summer 2025, with six of a total of 18 drillings carried out that year, starting from the centre of the island towards the southern intertidal flats. In 2026, drilling will shift from the island centre to the northern beach, followed by drilling under the mainland dike in 2027. Cable installation is scheduled for 2028 and 2029.
To minimise environmental disruption, Amprion is combining both projects into a single construction effort. This approach allows six drillings per season and improves efficiency. The construction site on Norderney was prepared before the bird breeding season, ensuring that major earthworks and material transport were completed ahead of the summer tourism peak.
BalWin1 and BalWin2 will each transmit up to 2,000 MW of power from North Sea wind farms to the grid. Submarine cables will extend 155 km (BalWin1) and 165 km (BalWin2) before reaching land via Norderney. Onshore, the cables will run approximately 205 km and 215 km, respectively. While both routes will be largely parallel, they will diverge towards their respective grid connection points in Wehrendorf (BalWin1) and Westerkappeln (BalWin2). Commissioning is planned for 2030 and 2031.
