Viking Link Interconnector is a 767km-long, high-voltage direct current (HVDC) transmission link under construction to interconnect the electricity networks of Denmark and Great Britain. It will be one of the world’s longest interconnectors following its completion.
National Grid Viking Link, a subsidiary of the UK’s National Grid, and Energinet, the Danish national transmission system operator (TSO), are developing the interconnector project through a 50:50 joint venture (JV) partnership.
The total investment in the project is estimated at about €2bn ($2.25bn). Construction of the interconnector began in July 2020 and is expected to be completed in 2023.
The Viking Link HVDC Interconnector will allow the bi-directional transmission of up to 1.4GW of clean energy between the UK and Denmark, ensuring a reliable electricity supply in both countries.
The cross-border electricity trade opportunity delivered by the project is expected to help bring down the wholesale price of electricity in the UK.
The project will provide the UK access to Danish wind power resources and is expected to supply renewable energy to 1.5 million UK homes upon completion.
Viking Link interconnector project design and route details
The Viking Link Interconnector project will connect to the existing 400kV Bicker Fen substation in Lincolnshire, UK, and the 400kV Revsing substation in southern Jutland, Denmark.
A converter station will be built in each country. Two parallel HVDC submarine cables, each 625km long, will be laid in the North Sea to connect the converter stations at both ends.
The project will also involve the installation of underground cables to connect the converter stations to the two countries’ respective substations.
The subsea route of the HVDC transmission system is through the exclusive economic zones (EEZs) of Denmark, Germany, the Netherlands and the UK.
The Danish side of the project includes two 75km-long onshore underground cables that will run between Blåbjerg, on the west coast of Jutland, and the Revsing substation. The cables will take the subsea route from the Blåbjerg landfall site.
On the UK side, the subsea cables will make landfall at Boygrfit, East Lindsey. They will be connected to a converter station at North Ing Drove, South Holland, through two 66.5km-long underground HVDC cables. The converter station will convert the transmitted electricity from DC to AC and vice versa.
From there, the electricity will be transferred to the existing National Grid substation at Bicker Fen.
The project secured a green loan worth $743m in June 2020. Provided by multiple export credit agencies, the loan included $255m from Euler Hermes Export Credit and $488m from Servizi Assicurativi del Commercio Estero (SACE) Export Credit.
The loan facilities were structured by BNP Paribas’ Corporate & Institutional Bank (CIB) and Euler Hermes Agent. HSBC Bank and Natwest provided bookrunner, mandated lead arranger (MLA), lender, and agent services.
Energinet received a ten-year loan of €134.4m ($160.21m) from Nordic Investment Bank (NIB), an international financial institution based in Finland, in March 2021. A second loan worth €201.67m, with a ten-year term, was awarded by NIB in March 2022.
Siemens Energy, a German technology firm, was selected to supply and install equipment for the two converter stations of the project. The company started work on the converter station in Lincolnshire in November 2020.
It also installed a hydrogen fuel cell system to provide off-grid power and heat to the construction site. The fuel cell system was developed by Siemens Energy and its partner GeoPura.
Cables for the project are being manufactured and installed by Italian cable manufacturer Prysmian Powerlink and NKT HV Cables, a Swedish company.
Prysmian was contracted to supply and install 1,400km of submarine and land cables for the project in July 2019. It is using its Leonardo da Vinci cable-laying vessel for the installation.
NKT was contracted to supply 150km of HVDC onshore power cables for the project.
Balfour Beatty, a UK-based construction company, received a €90m ($100.24m) contract to perform civil engineering and installation of 68km of onshore cables across Lincolnshire in December 2019.
Ian Farmer Associates, a land surveyor based in England, was selected to conduct surveying works, and NMCN, a UK-based civil engineering firm, was engaged to construct the access road to the UK converter station site.
Dutch company Fugro conducted a seabed survey for the Viking Link project.
Munck Piping, a Danish company, is responsible for onshore cable installation in Denmark, from the west coast to the Revsing HV substation.
Bravida Danmark was selected by Energinet to install electrical, cooling, plumbing and automation, as well as heating, ventilation and air conditioning (HVAC) systems at the converter station at Revsing.
Intertek and NIRAS were engaged to provide marine consultancy services for the project in December 2015. Intertek was also appointed to provide total quality assurance services to support unexploded ordnance (UXO) survey and inspection activities for the project in September 2018.