The grid connection, which is now in commercial operation, can transmit 690MW of clean electricity from wind farms to meet the requirements of around nearly 900,000 households.
The HelWin2 grid connection’s offshore platform is located around 85km off the northwest coast of the island of Helgoland.
TenneT managing board member Lex Hartman said: "Step by step we are implementing the offshore development goals set by the German government.
"The goal of the German government is to have 6.5 gigawatts of offshore wind power capacity installed by 2020. TenneT has already achieved more than 50% of this target."
HelWin2 is the fourth high voltage direct current (HVDC) grid link completed by Siemens after the 800MW BorWin 2, the 576MW HelWin 1 and the 864MW Sylwin 1 links, which were delivered to TenneT earlier this year.
The four links will have a combined transmission capacity of more than 2.9GW, enough to power to around four million German households.
The fifth link, 900MW BorWin 3 is planned to begin operations in 2019. Siemens and its partner, Petrofac, bagged the contract to supply fifth link in spring 2014.
Upon commissioning, the five installed network grids will have a total transmission capacity of 3.8GW, and will be able to offshore wind power to nearly five million households.
