Construction start of DolWin 6 converter station


The so-called DolWin wind farm cluster in the southwestern part of the German Bight is an important component of Germany’s future regenerative energy supply. TSCNET shareholder TenneT, the Dutch-German transmission system operator (TSO), is responsible for transferring the DolWin energy ashore. The DolWin1 and 2 onshore connections are in operation since 2015 and 2016 respectively, and DolWin 3 is ready for feed-in since September 2018. The other ongoing projects, DolWin 5 and 6, are also making good progress.

DolWin6 is a 900MW DC connection with a length of 90km. The associated offshore platform to convert the three-phase current generated by the wind farms into DC is DolWin kappa. Half of the 90km distance is covered by submarine cables and the other half by underground cables to transport the electricity from the landing site in Hilgenriedersiel to the TenneT facilities in Emden in the Lower Saxony region of East Frisia.

On the grounds of the Emden/Ost substation, the TSO is building a converter station and a transformer station to convert the DC back into three-phase current and feed it into the onshore grid. The first construction phase of the DolWin6 onshore converter station has now begun with the foundation work. In the next 6 months, 1000 piles with a length of up to 24 meters will be drilled into the ground to create a stable foundation for the station.

TenneT begins construction of the DolWin6 onshore converter station (pictures: TenneT)

> See TenneT Tweet, in German (html)

See article on single page

DolWin gamma successfully installed


The Dolwin3 grid connection for offshore wind farms in the south-western part of the German Bight has the capacity to supply more than one million households in Germany with green energy. The 900MW DC connection – the third in the DolWin cluster – is carried out by TSC member TenneT, the Dutch-German transmission system operator (TSO), and GE, the general contractor of the whole offshore project. With the installation of the DolWin gamma converter platform, another major step towards the successful completion of Dolwin3 has now been taken.

DolWin gamma was shipped on 15 June in Warnemünde harbour in the German federal state of Mecklenburg-Vorpommern. From here it took six days along the German and Danish coast to reach the final destination in the north of Borkum island within a distance of 80 kilometres to the coastal line of Germany. During spells of fine weather the platform was installed onto the so-called jackets, the platform substructure that already had been erected in 2016.

DolWin gamma converts the AC produced by the wind farms into DC, which is transported via submarine and underground cables to the onshore converter station Dörpen West, where the reconversion into AC takes place. Wilfried Breuer, member of TenneT’s executive board and Director Offshore, declares: “The converter platform is one of the largest visible indicators of the German energy transition. Flagship projects such as DolWin3 are essential to provide customers from the north with wind power and to make renewable energy a reality.”

> See TenneT press release, in German (html)

Picture: TenneT


See article on single page