References

The converter platform “BorWin beta” connects the North Sea offshore wind parks “Global Tech I” and “Veja Mate” via an HVDC submarine cable to the high-voltage network of the network operator TenneT TSO located on the mainland.

Main characteristics of the platform
Total weight: 16,550 tonnes (11,900 tonnes topside, 4,650 tonnes jacket incl. foundation piles)
Foundation: 6 piles (total length 83.5 metres)
Integration into the seabed: 50 Meter
Total height topside: 39 metres
Transmission technology: direct current
Distance from the mainland: 110 kilometres
Power: 800 megawatts

The HVDC converter platform “HelWin alpha” was built by Nordic Yards on behalf of Siemens Energy and was set up as part of the offshore windpark network connection project within the Helgoland windpark cluster (“North Sea East” and “Sea Wind South / East”) in the North Sea, north of the island of Helgoland.
 

Main characteristics of the platform

Total weight: 17,300 tonnes (13,000 tonnes topside, 4,300 tonnes jacket incl. foundation piles)
Foundation: 10 piles (total length 96 metres)
Integration into the seabed: 66 metres
Total height topside: 41 metres
Transmission technology: direct current
Distance from the mainland: 85 kilometres
Power: 576 megawatts

The HVDC converter platform “SylWin alpha” was built by Nordic Yards, on behalf of Siemens Energy. Like both of its predecessors, SylWin alpha consists of two main components – the foundation (jacket) and the topside with the areas for the following facilities: those for platform own systems, and those for HVDC technology and the helicopter deck. The platform which lies approx. 70 kilometres west of the island of Sylt was anchored in the North Sea for the connection of the OWP DanTysk”, “Sandbank” and “Butendiek”. With a height of more than 90 metres, a width of 56 metres and a length of 82 metres, SylWin alpha is larger than the predecessor projects BorWin beta and HelWin alpha, completed by Nordic Yards. SylWin alpha is able to supply more than a million households with green wind energy.
 

Main characteristics of the platform
Total weight: 25,500 tonnes (15,400 tonnes topside, 10,100 tonnes jacket incl. foundation piles)
Foundation: 9 piles (total length 106 metres)
Integration into the seabed: 69 metres
Total height topside: 26 metres
Transmission technology: direct current
Distance from the mainland: 70 kilometres
Power: 864 megawatts

The HVDC converter platform “DolWin gamma” was built by Nordic Yards, on behalf of Alstom Grid/GE Renewable Energy. The platform was connected to the OWP “Borkum Riffgrund 2” and “Merkur Offshore” in the South West part of the German North Sea. The “DolWin gamma” is the fourth HVDC (High Voltage Direct Current) converter platform established by Nordic Yards across Germany as a market leader in the construction of converter platforms.

The offshore platform was set up on a two-part foundation anchored in a water depth of 27.5 metres. The exact alignment of the two foundations in relation to each other and to the topside was done by using a steel template, which was removed from the seabed again after the installation was completed. In addition to the design and the manufacture, this contract, for the first time, also included the full scope of the work package for transportation and installation of the platform in the North Sea.
 

Main characteristics of the platform 
Total weight: 34,700 tonnes (18,450 tonnes topside, 16,250 tonnes jacket incl. foundation piles)
Foundation: 18 piles (total length 78 metres)
Integration into the seabed: 62 metres
Total height topside: 76 metres
Transfer technology: direct current
Distance from the mainland: 80 kilometres
Power: 900 megawatts