DolWin1 offshore wind energy link hand over

Leading power and automation group, ABB, has successfully commissioned and handed over the DolWin1 offshore wind grid connection to the Dutch-German transmission system operator, TenneT.

The 800 megawatts (MW) High Voltage Direct Current (HVDC) link connects the Borkum West II and Borkum Riffgrund I offshore windfarms 75km off the German coast in the DolWin cluster, with the country’s transmission grid.

The DolWin1 grid connection can integrate 800 MW of offshore wind power, enough to supply around one million households with clean energy.

Claudio Facchin, President, ABB Power Systems division, said: “We are proud to hand over the DolWin1 offshore wind grid connection to TenneT and to make a significant contribution to Germany’s target of increasing its share of renewables in the energy mix.”

The DolWin1 grid connection is part of Germany’s ambitious energy transition roadmap, called “Energiewende”, which foresees the generation of more than 6.5GW from offshore wind by 2020 and 15GW by 2030.

ABB deployed its pioneering 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.

HVDC is the technology of choice for transmitting large amounts of power, over long distances, efficiently and reliably through overhead, underground and sub-sea links with minimum losses.

The windfarms are connected via submarine cables to DolWin alpha, the offshore converter station. Here the alternating current from the windfarms is converted into direct current before being transmitted at a voltage of +/- 320 kilovolts (kV) via 165km of extruded DC submarine and underground cables to the grid connection point at the Dörpen West substation in Heede, northern Germany.

By Anne-Marie Causer