ABB has successfully commissioned and handed over the DolWin1 offshore wind grid connection to the Dutch-German transmission system operator TenneT.
The 800 MW HVDC link connects offshore wind farms in the DolWin cluster around 75 km off the German coast with the country’s transmission grid. The DolWin1 grid connection can integrate 800 MW of offshore wind power. It is a contributor to Germany’s ambitious energy transition "Energiewende" policy, which foresees the generation of more than 6.5 GW from offshore wind by 2020 and 15 GW by 2030.
ABB deployed its voltage source converter (VSC) technology, called HVDC Light, for the project and was responsible for the design, engineering supply and installation of the offshore and onshore converter stations, as well as the submarine and underground cable systems.
The wind farms Borkum West II and Borkum Riffgrund I are connected via submarine cables
to DolWin alpha, the offshore converter station. Here the AC wind farm output is converted to DC before being transmitted at ± 320 kV) via 165 km of extruded DC submarine and underground cables to the grid connection point at the Dörpen West substation in Heede, northern Germany.
HVDC is now the most deployed technology for transmitting large amounts of power over long distances efficiently and is therefore a key focus area in ABB’s ‘Next Level’
strategy. ABB pioneered HVDC more than 60 years ago and further developed it in the 1990s by introducing voltage sourced converter technology. With the DolWin1 project ABB has now delivered 16 out of the 22 VSC HVDC projects that are in commercial operation around the world.