National Grid, Tennet to study joint GB-NL offshore wind/interconnection project

London — National Grid Ventures and Tennet are to study development of 2 GW of interconnection between Britain and the Netherlands connecting up to 4 GW of offshore wind, the network companies said Sept. 22.

The two companies aim to have a "path-finder" project defined by the end of 2021 with a view to delivering an operational asset by 2029.

"The development would be the first of its kind for the UK and the Netherlands in the North Sea," the companies said.

The UK targets 40 GW of offshore wind by 2030, while the Dutch have targeted 11.5 GW by 2030 and 20 GW-40 GW by 2050.

"Delivering such large-scale offshore wind growth efficiently will require significant amounts of new infrastructure and close cooperation between countries around the North Sea," the partners said.

The plan follows a decision by the Dutch government to future-proof 2 GW of HVDC offshore grid planned for the IJmuiden Ver Wind Farm Zone, 80 km off the country's northwest coast.

"By connecting into both systems, the multi-purpose interconnector will enable spare transmission capacity to be used to trade electricity between the countries, thereby increasing the potential utilisation of offshore infrastructure," they said.

The meshing of interconnection with offshore wind mitigates the environmental impact on coastal communities versus the current approach in which interconnectors and wind farms are developed and connected separately, they said.

Round 4

The project could entail four convertor stations, one each onshore in the UK and the Netherlands, and two offshore -- one in UK waters connecting UK wind farms, and one in Dutch waters connecting Dutch wind farms, National Grid Ventures told S&P Global Platts.

HVDC subsea transmission worked best when wind farms were at least 50 km offshore, "and the radial connection being displaced would have been longer," it said.

Offshore convertor stations would be positioned as close to windfarms as possible, allowing for technical restrictions and the best route for the overall project.

"UK windfarms which are in early or mid-development would be natural partners," National Grid said, noting in particular projects that may come out of The Crown Estate's Round 4 seabed leasing process.

Round 4 is to make at least 7 GW of new seabed rights available in UK waters for construction to 2030.