ABB reaches offshore milestone

The 320-kilovolt converter station, housed on an offshore platform, has a 916 MW power transmission capacity, making it the world’s most powerful installation of its kind, enough to power more than 1,000,000 households with clean energy.

“After the successful handover of the DolWin1 link in July, this is another key milestone in the execution of our offshore wind projects,” said Ulrich Spiesshofer, CEO, ABB. “It is a further example of our focus on relentless execution and of the ongoing progress in the Power Systems division’s Step Change programme.”

It’s part of the DolWin2 project which will be operated by transmission system operator TenneT and will connect offshore windfarms in the North Sea’s DolWin cluster, currently the largest offshore wind farm cluster worldwide, with the German grid. The main function of the station will be to convert the electricity generated by the offshore windfarms from alternating current (AC) into high-voltage direct current (HVDC) for efficient and reliable transmission to the mainland.

DolWin2 is part of Germany’s energy transition roadmap, ‘Energiewende’, which foresees the generation of more than 6.5 gigawatts (GW) from offshore wind by 2020 and 15 GW by 2030. The DolWin1 grid connection, which ABB commissioned and handed over to transmission system operator TenneT at the end of July 2015, also contributes to this goal.

The complete platform including substructure weighs around 23,000 tonnes and is around 100m long, 70m wide and 100m tall. DolWin beta uses a self-installing gravity-based structure (GBS) concept, whereby the platform is slowly ballasted down to the seabed by filling the six columns with water, which will in the coming weeks be completely replaced by gravel to permanently secure the platform.

By Rachael Doyle