TenneT, as onshore and offshore transmission system operator, will connect 6.1 gigawatts of new offshore wind farms to the Dutch high voltage grid between 2024 and 2030.

TenneT will be using cost-efficient and future-proof technologies for this and the surroundings and environment will be spared as much as possible during construction.

Manon van Beek, CEO TenneT, said, “In doing this we are making an important contribution to accelerating the energy transition. Based on our experiences with innovative technology in Germany, we can now help realize Dutch ambitions for the development of offshore wind power with fewer cables, fewer platforms and with less spatial impact and less disturbance to the surroundings and the environment both at sea and on land.”

The wind power areas Hollandse Kust (west) and Ten Noorden van de Waddeneilanden will benefit from TenneT’s standardized AC-concept with offshore electrical substations of 700 MW. These pool the electricity from the wind farms. 220-kV cables then transport the wind electricity to the coast.

In the IJmuiden Ver offshore wind energy area, two direct current connections (comprising cables and converter stations) will be used; for the first time in the world with a 2,000 MW (2GW) capacity. The cables will have a 525 kV (525,000 V) voltage level. This makes optimum use of the area's scale and also corresponds with the wind industry wishes for larger wind farms. For a larger capacity of 2 gigawatt, just two instead of six cables are needed (lower costs) and this also takes up less space. Fewer routes will be required onshore and therefore the environment will be spared as much as possible.

csm 20190405 IJmuiden Ver offshore converter station 1 ec56f59282

Artist impression of a 2GW offshore converter platform for IJmuiden Ver

The step to realizing 2 GW power connections is possible because of TenneT’s unique experience with HVDC network connections in Germany. There, TenneT is connecting large-scale offshore wind farms based on direct current. Direct current cables of 2 GW on land also form the basis for the yet-to-be-constructed SuedLink and SuedOstLink. TenneT is using the high voltage level of 525 kV for the new international connection between Germany and Norway, NordLink.

In connecting the wind farms at IJmuiden Ver, two 2 GW offshore converter stations will be constructed to convert the alternating current generated by the wind farms into direct current. This technology prevents transmission losses. On land, converters will then convert the direct current into alternating current for further transmission and distribution to companies and households. Connecting to the most sensible points in the grid can also prevent large investments in the national high voltage grid. The offshore converters and wind turbines at IJmuiden Ver (approximately 80 km off the coast) will not be visible from land.