The North Sea offshore wind farm, which is located 85 km from the island Helgoland, will be connected to the grid via submarine cables and high-voltage direct current (HVDC) transmission technology.

To transport the energy Siemens will supply a voltage sourced converter and develop a connection with the transmission capacity of up to 576 MW.

The converter will be set up on an offshore platform and will convert alternating current into direct current for the transmission. The station will be delivered on a floating self erecting platform and towed by tugs to its destination in the open sea where the water is 23 m deep.

The HelWin 1 project is due to be completed by the middle of 2011 with the entire grid connection for the offshore wind farm to be up and running by 2013.