Testing and installation of the world’s longest onshore and subsea power cable, which connects Denmark and the UK, is complete.

Viking Link is a £1.7 billion ($2.15 billion) joint venture between the UK’s National Grid and Denmark’s Energinet, and it’s due to come online by the end of this year.

Italy-based principal contractor Prysmian Group, responsible for designing, manufacturing, and installing most of Viking Link, announced today that it has completed the installation and high-voltage testing of both its land and subsea power cables. Copenhagen-based NKT also worked on cable installation.

The Prysmian Group manufactured the cables at its factory in Arco Felice, near Naples. The Leonardo da Vinci (pictured above), a cable-laying vessel, was used in its first-ever offshore campaign, along with the vessel Cable Enterprise.

The 765-kilometer-long (475-mile-long) onshore and subsea high voltage direct current (HVDC) interconnector joins Lincolnshire in the UK with Jutland in Denmark. The single-core, mass-impregnated, paper-insulated submarine cables pass through British, Dutch, German, and Danish waters.

The HVDC interconnector will allow up to 1.4 gigawatts (GW) of clean energy to move between the two countries. That’s enough to power approximately 1.4 million UK homes.

Viking Link’s website says, “The cable was tested to 735,000 volts equivalent to 1.4 times its operational voltage of 525,000 volts, which proved the cable terminations, land, and submarine joints.”

Viking Link project director Phil Sandy said:

We are delighted to have successfully completed the final cable test. This means the cable is ready to operate once the commissioning process is complete. This is a key milestone in the project and marks the end of the cable installation process.

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Photo: Port of Middlesbrough; Map: Prysmian Group

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