TenneT delivers grid connection three months ahead of schedule

Monday 15 January 2024

After extensive preparation and three years of construction on land and sea, the grid connection for Hollandse Kust (west) Alpha is officially ready for commissioning. This means that Ecowende can connect the wind turbines, which will be located about 50 kilometers off the coast of Egmond aan Zee, to grid operator TenneT's 'socket' at sea.

Whereas completion was scheduled for the first quarter of 2024, TenneT received the grid readiness certificate from DNV before the holidays in 2023. This makes the grid connection of the 'socket at sea' to the national electricity grid officially ready for use after a series of extensive tests. Via the cable connection coming ashore at Heemskerk/Wijk aan Zee, power has been put on this new part of the grid from the high-voltage substation along the A9 near Beverwijk.


"With this, we finished three months ahead of schedule," TenneT interface and system integration manager Anne-Marie Taris announced. She is responsible for the system integration and flawless cooperation of the transformer station in Wijk aan Zee, the underground (sea) cable connection and the platform at sea. "A fine achievement that the Equans/Smulders contractor combination can also be proud of. Both the teams at sea and on land have done a great job in recent months."

Ecowende, as developer of wind farm Hollandse Kust (west) lot 6, has already installed, integrated and tested communication equipment on the Hollandse Kust (west) Alpha platform. Folkert Visser, CEO and Project Director at Ecowende: "Our congratulations to TenneT on this great milestone! This delivery gives us the certainty that we can connect our wind turbines as soon as they are ready. The good cooperation we have had so far with TenneT gives us great confidence for the successful implementation of the next milestones."

A connection every year

In 2016, the national government designated TenneT as the offshore grid operator. This means that TenneT will connect the new offshore wind farms to the national high-voltage grid. The Ministry of Economic Affairs and Climate commissioned five standardized grid connections of 700 megawatts by 2024. A connection from sea to land has been completed every year since 2019.

Within schedule and budget

Taris: "In the Energy Agreement ten years ago, it was agreed that by the end of 2023 at least 4.5 gigawatts of installed capacity for wind at sea had to be realized. That is equivalent to the annual consumption of five million households. That assignment has been achieved on schedule and on budget by all parties involved. Earlier than planned, grid connection number six has now been added with Hollandse Kust (west) Alpha."

Second platform

Last September, the more than 3,600-ton superstructure (topside) of the offshore socket was placed on the undercarriage (jacket). Almost two years earlier, the first steel cut took place in Antwerp for this second transformer platform built by Equans/Smulders for TenneT. Sustainable electricity is already being brought ashore from the first platform for wind farm Hollandse Kust (north).

Timely completion

Following the installation of the topside, a hotel ship was placed next to the platform so that the Equans/Smulders team could carry out the welding work and further installation. Earlier, Jan de Nul Group and LS Cables installed the two sea cables that will soon bring the green power ashore in 2023. "Despite the challenging weather conditions of recent times, we managed to perfectly complete the installation of the platform and all the test work for the connection in a timely manner," Taris said.

© Images and copy in collaboration with TenneT and Flying Focus