Dutch power transmission network operator TenneT is proposing to develop a new transmission hub in the North Sea to which numerous offshore wind farms could be connected and from which offshore wind power generation could be transmitted over direct current cables to the North Sea countries, i.e. the Netherlands, the United Kingdom, Belgium, Norway, Germany and Denmark.
The project would consist of creating a modular island (each module of 6 km²), to connect around 30 GW of offshore wind capacity. TenneT expects the island project (ideally Dogger bank in the United Kingdom) to reduce connection costs for offshore wind projects by allowing the use of the far cheaper alternating current (AC) connections between wind parks and the island; power would be transmitted to the mainland with direct current (DC) connections. This would increase the present efficient utilisation of a connection between the wind park and the mainland from roughly 40% towards 100%.
TenneT is already developing offshore wind transmission capacities in the areas of Borssele, Hollandse Kust (zuid) and Hollandse Kust (noord), which are expected to be commissioned in 2023. Other areas including IJmuiden Ver (5-6 GW) are under consideration; TenneT is open to international cooperation between IJmuiden Ver and a wind area in the United Kingdom such as East Anglia by 2025-2030. The island could be built on the Dogger Bank between 2030 and 2050.