In a significant leap towards sustainable energy, TenneT, the European grid operator, has successfully completed the DolWin6 project. This 90km-long direct current (DC) connection boasts a transmission capacity of 900MW, linking the North Sea Cluster 3 offshore wind farms to the German power grid. The project, initiated in July 2017, reached its completion milestone in September 2023, marking TenneT's 13th German offshore grid connection.

At the heart of DolWin6 is the DolWin kappa offshore converter station, connected by a sea cable and a 45km underground land cable. This comprehensive transmission project also includes a land converter station and a transformer station, contributing to TenneT's increased offshore transmission capacity, now exceeding 11.5GW.

The DolWin6 transmission cable features advanced technology with two parallel 320kV high-voltage direct current (HVDC) cables, offering efficient and reliable power transmission. Siemens' HVDC Plus converter technology is a key component, utilizing a modular multilevel converter design and significantly reducing space requirements.

The DolWin kappa platform, weighing 11,000 tonnes, is a marvel of engineering, designed for a 30-year operational life at water depths of approximately 29m. Connected to the existing DolWin beta platform, it eliminates the need for permanent diesel generators through a direct 10kV cable connection.

Major contributors to the DolWin6 success include Siemens, Nexans, Dragados Offshore, Allseas, DEME, Matthäi, Heinen & Hopman, Teknotherm, and SeaRenergy. This collaborative effort showcases the integration of cutting-edge technology and expertise in the renewable energy sector.

Source: power-technology.com