The first electricity network plan for the German North Sea has been released by the country's federal shipping office, the Bundesamt für Seeschifffahrt und Hydrographie (BSH). It will act as a building block towards creation of an transnational North Sea transmission grid.
The plan is based around the German government’s target of achieving 25GW of offshore wind installed capacity by 2030, of which 21GW is expected to be located in the North Sea. This will require 25 offshore converter platforms and 3,880km of marine transmission cables in the German North Sea, concludes the plan.
The offshore network plan organises all planned and permitted North Sea wind farms, up to a maximum distance from shore of 120km, into 13 clusters and specifies cable routes or route corridors for the subsea cables that will connect these clusters to the onshore transmission system.
It sets out the sites for offshore transformer stations and converter platforms, the routes for maritime cables that cross national borders, and the cable crossing points from the German exclusive economic zone into the German 12 nautical mile (coastal) zone.
The plan defines a standard system capacity of 900MW for each of the converter platforms and a 900MW transmission capacity for each 320kV cable system. These parameters provide a framework for connecting converter platforms to each other that, in future, will allow the transmission system operator to transmit electricity via an alternative converter platform and route if there is a problem with any part of the system.
Standardising technical parameters also opens up the possibility of connecting the German offshore network with a transnational North Sea network, emphasises the BSH.