As part of the DolWin5 project, the “first steel cut” marked the start of the construction of the DolWin epsilon offshore converter platform in Singapore on December 1st.
The event took place on a small scale and under strict hygiene regulations at the Keppel Offshore & Marine shipyard.
The 900 megawatt DolWin5 high-voltage direct current (HVDC) transmission system will connect the Borkum Riffgrund 3 offshore wind farm off the coast of Lower Saxony with the extra-high voltage grid on land.
The wind power produced at sea will be transmitted as three-phase current to the DolWin epsilon converter platform, using the innovative 66-kV connection: the wind farm will be connected directly to the offshore platform.
This eliminates the need for substations in the wind farms. DolWin epsilon converts the three-phase current into direct current and transports it a total of 130 kilometres to the onshore converter station in Emden/East. Here the electricity is converted back into three-phase current and fed into the extra-high voltage grid via the converter station. Due to the distance and the power to be transmitted, direct current is ideal for low-loss transport.
In May 2019, the transmission system operator TenneT selected the consortium of Aibel and Keppel FELS to implement key elements of the DolWin5 offshore grid connection project.
The approximately 80-meter long, 70-meter wide and 80-meter high steel structure of the DolWin epsilon offshore platform is manufactured at the company’s shipyard in Singapore. After completion of the construction work and installation of the better part of the technical equipment DolWin epsilon will be transported from Singapore to Haugesund, Norway.
There the company Aibel will install the converter and transformers. HITACHI ABB will supply the extra-high voltage direct current technology as a subcontractor of Aibel and Keppel FELS. In addition to the converter system, the platform will provide accommodation for 50 people, a helicopter landing pad and a crane and lifeboat.