DolWin4 and BorWin4

Bringing North Sea Wind Power on shore

In order for Germany to achieve its climate targets, offshore wind farms are to deliver as much electricity as 40 large coal-fired power plants by 2030. This requires not only new offshore windfarms, but also new cables connecting them to the transmission grid. This is the remit of the DolWin4 and BorWin4 grid connection systems that are planned.

Grid Connection in southern Emsland

Multiple wind farms are already putting the transmission grid in the coastal region of Lower Saxonyunder great strain. The Federal Network Agency has therefore decided to relocate the connection points for two new wind power connections much further inland: to Lingen in southern Emsland (a district which borders North Rhine-Westphalia in the south and the Netherlands in the west). This is where Amprion’s Hanekenfähr transformer station is located. To date, this substation connects the Emsland nuclear power plant to the transmission grid. After the shutdown of this plant in 2022, transmission capacities of 1.4 gigawatts are freed up at this major grid hub. These capacities that will in future be used to transport wind power to the consumption centres in the west and south of the country. To this end, Amprion has been legally mandated to build the grid connection systems DolWin4 and BorWin4 from the North Sea to Lingen. From the wind farms to the coast, these connections will be run as submarine cables, passing under the island of Norderney. On land, the installations will berealised as underground cables.

Going into operation in 2028

The two offshore grid connection systems planned will be installed parallel to one another on land and for the most part at sea, too. DolWin4 is an approximately 215 kilometre-long connection, some 60 kilometres of which will be laid at sea. BorWin4 will have a total route length of around 280 kilometres, with around 125 kilometres at sea. The land sections of both DolWin4 and BorWin4 are planned as underground direct current cables. Each of them will be able to transmit a capacity of 900 megawatts. In total, this corresponds roughly to the needs of a large city like Hamburg with 1.8 million inhabitants. The grid connection systems will go into service in 2028.