TenneT’s OSS-Less Connection for Ørsted and EnBW German Projects

TenneT has entered into agreements with Ørsted and EnBW to use a grid connection concept on future wind farms in the German North Sea which will link the turbines directly to the converter platforms.

Under the deals, Ørsted’s Borkum Riffgrund West 1 & 2 and OWP West, as well as EnBW’s He Dreiht offshore wind projects will be connected directly from the turbines to the offshore converter platform via 66kV cables.

This brings to the possibility of not having to construct an offshore substation at the wind farms, nor the export cables, TenneT said.

“This connection concept leads to an enormous cost reduction in the wind farms and for the grid connection. With the 66 kV direct connection, we have developed a new generation of cost-efficient offshore grid connections for the German North Sea, which will make an important contribution to the energy transition,” said Tim Meyerjürgens, Managing Director of TenneT.

According to TenneT, Germany’s Federal Maritime and Hydrographic Agency (BSH) will use the concept for respective approval procedures regarding the grid connections for the planned wind farms, while initial discussions were already held.

The transmission system operator believes that the concept will be a standard alternative to 155kV connections featuring an offshore substation as of 2026, if the distance between turbines and the converted platforms permits.

To remind, at Germany’s first competitive tender, held in 2017, EnBW secured the rights to develop the 900MW He Dreiht wind farm and Ørsted won contracts for its 240MW OWP West and 240MW Borkum Riffgrund West 2 wind farms. The next year, in the second auction round, Ørsted secured the rights for the 420MW Borkum Riffgrund West 1.

The projects will be built without subsidies and are expected to be commissioned by 2025.