Ground broken for DolWin4 and BorWin4

4C Offshore | Tom Russell
By: 19/07/2022 Amprion

Ground has been broken for the
DolWin4 and BorWin4 offshore grid connection systems marking the commencement of construction of the two projects. Both grid projects will connect North Sea wind farms with the German onshore transmission grid.

This summer, Amprion will drill the first four of a total of twelve horizontal wells in the coastal sea. The drilling will be carried out using the HDD (horizontal directional drilling) method. In this process, cable protection tubes are inserted into the drilling channels, into which the DC (direct current) cables are subsequently pulled.

For the construction work, Amprion is using a construction window set by the authorities between mid-July and the end of September. This summer, Amprion will drill a length of around 1,100 meters from the center of the island in the direction of Nordstrand. In 2023, the borehole will be drilled from the center of the island in a southerly direction, before the coastal protection dike near Hilgenriedersiel is finally crossed in 2024.

On Norderney's North Beach, Lower Saxony's Environment Minister Olaf Lies and island mayor Frank Ulrichs symbolically broke ground with employees of Amprion. Representatives of Lower Saxony authorities as well as organizations from the fields of nature conservation and tourism took part in the ceremony.

"The expansion of offshore wind energy is a central pillar of our energy transition. Lower Saxony plays a special role in this. We are becoming the gateway and hub for climate-friendly energy for all of Germany. Particularly in view of the current major energy policy challenges, we need not only expansion, but also grid connection. That's why dates like today send out an encouraging signal. Because progress is also being made with grid connection. That's why I'm particularly pleased to be able to congratulate Amprion on the first construction activities in the offshore sector. We need wind power in particular to ensure a free, clean and independent energy supply," said Lower Saxony's Environment Minister Olaf Lies.

"The majority of previous offshore grid connections run below Norderney," said Frank Ulrichs, mayor of the island of Norderney. "Our island is thus making a major contribution to the success of the energy transition. I am particularly pleased that Amprion already set up the construction site last winter. This meant that many transports could already be handled before the summer season, which is important for us. As an island, we expressly welcome this and are pleased with the good cooperation."

"In the future, the large power plants to supply the industrial regions and citizens will be located in the North Sea" says Amprion CTO Dr. Hendrik Neumann. "DolWin4 and BorWin4 are at the beginning of a series of offshore grid connections that our company will realize in the coming years." Amprion is currently planning five offshore grid connection systems. Others have already been confirmed in the grid development plan."

"For the first time, we are bundling the drilling for two projects within one construction window" said Dr. Carsten Lehmköster, one of the two managing directors of Amprion Offshore GmbH. "This allows us to accelerate the projects while minimizing the intervention." His colleague Peter Barth adds, "We are moving in an extremely sensitive area here in the national park. That required good and intensive coordination with the relevant authorities." However, he also finds critical tones with regard to the tasks ahead: "The expansion targets for 2030 are very ambitious under the current conditions. Especially the crossing of the territorial sea poses a problem for acceleration without an adjustment of the framework conditions."

The
DolWin4 and BorWin4 offshore grid connection systems, which run largely in parallel, are scheduled to go into operation in 2028 and 2029. From the North Sea wind farms, the cables will initially run 60 and 125 kilometers at sea. They cross below the island of Norderney and reach the coast in the Hilgenriedersiel. From there, they run for around 155 kilometers as underground cables toward the Hanekenfähr substation in Lingen (Ems), where Amprion will connect them to its transmission network. There, the Emsland nuclear power plant will be taken off the grid at the end of 2022. They will have the capacity to transmit 1.8 GW off electricity generated offshore.


For more information on offshore wind farms worldwide, click here.