Viking Link: World’s longest undersea power cable connects UK and Denmark

The 764-kilometre-long Viking Link HVDC submarine cable linking the electricity grids of Great Britain and Denmark has been laid, creating a world record-breaking continuous link between the two countries.

The final section of the state-of-the-art high-voltage subsea cable was completed on Tuesday, connecting Bicker Fen in Lincolnshire with Jutland in Denmark. Laying the cable was completed in the North Sea by Prysmian’s Cable Laying Vessel “Leonardo da Vinci” and its team.

Viking Link is UK grid operator National Grid’s sixth interconnector, with the previous operational cables already linking the UK with France (IFA and IFA2), The Netherlands (BritNed), Belgium (Nemo Link) and Norway (North Sea Link).

Once completed, the £1.7 billion (€2 billion) Viking Link project will allow electricity to be transferred between National Grid and Danish system operator Energinet. It will be the world’s longest land and subsea interconnector and will enable the sharing of enough green electricity to power 1.4 million UK homes.

The complex operation to join the cables took place in Danish waters over several days and involved lifting the sections of the cables out of the water to join each conductor strand together on the cable laying vessel.

“This is a fantastic moment for the UK and Denmark, and a key milestone for the world record project as we join the electricity networks of our two countries for the first time,” said Rebecca Sedler, managing director for Interconnectors at National Grid.

“After years of planning and construction work, today’s announcement is testament to the hard work and dedication of our team and our partners on both sides of the connection.

“Interconnectors bring huge benefits to the UK, acting as clean energy super-highways, allowing us to move surplus green energy from where it is generated to where it is needed the most. That means that we can import cheaper and cleaner energy from our neighbours when we need it, and vice versa.

“As energy systems build up their offshore wind generation, interconnectors will become critical for transporting clean and green energy and helping to manage the intermittent nature of renewable sources.”

While an impressive milestone, the 764-kilometre-long Viking Link will likely not remain the world’s longest HVDC submarine cable, if the Australia-Asia PowerLink (AAPowerLink) is completed as planned.

Set to connect solar and battery storage capacity in Australia’s northernmost capital city Darwin with both Indonesia and Singapore, AAPowerLink is expected to run a total length of 4,200 kilometres.