The world’s longest land and subsea interconnector began commercial operations on 29 December 2023. 

National Grid’s new Viking Link electricity interconnector became operational this afternoon, transporting power between the UK and Denmark. The link has a capacity of 1.4 GW and stretches 475 miles under land and sea, connecting Bicker Fen substation in Lincolnshire with Revsing substation in southern Jutland, Denmark. 

The £1.7 billion project is a joint venture between National Grid and Danish System Operator Energinet and has the capacity to transport enough electricity for up to 2.5 million* UK homes, bringing over £500 million of cumulative savings for UK consumers over the next decade* due to cheaper imported power from Denmark.

Construction on Viking Link, National Grid’s sixth interconnector, started in 2019, with more than four million working hours spent to date. 

National Grid’s interconnector business is run by National Grid Ventures (NGV), which operates outside of National Grid’s core regulated businesses in the UK and US. NGV develops, operates and invests in energy projects, technologies and partnerships to accelerate the development of our clean energy future.

Viking Link will bring huge benefits for UK consumers, including cheaper, lower-carbon power and increased energy security, as the UK can call on additional power from Denmark when needed. 

Initially, Viking Link will be operating at a capacity of 800MW before increasing over time to 1.4GW. National Grid and Energinet will work together to bring the asset to full capacity over the coming year. 

In its first year of operation, Viking Link is expected to save approximately 600,000 tonnes of carbon emissions – this is equivalent to taking roughly 280,000 cars off the road.

Viking Link has a converter station at each end of the cable, where the power is transformed to the correct frequency before being fed into each country’s transmission system. Principal Contractor Siemens Energy built the converter station in the UK, while Energinet built the Danish converter station. Siemens Energy designed, installed and commissioned the electrical assets on both sides.

Prysmian Group manufactured and laid the HVDC offshore cable. The cable was laid on the seabed using a custom-made vessel, The Leonardo Da Vinci, which was then buried using Asso trenchers.   

Prysmian Group manufactured the HVDC land cable, which Balfour Beatty installed; Prysmian Group manufactured and installed the offshore section in the UK, and NKT manufactured the Danish land section, which Monck installed. 

The UK land cable comprised 118 sections stretching for 67km between Bicker Fen and Sutton-on-Sea, where the subsea cable begins. It was connected to the UK’s National Transmission Network by National Grid Electricity Transmission at the existing Bicker Fen substation. 

Interconnectors enable fast, flexible energy sharing between countries, making them an ideal tool for managing the intermittent nature of renewable energy sources. 

National Grid launched the UK’s first interconnector (IFA) to France in 1986. Since then, it has built five more, including a second link with France (IFA2) and further connections with the Netherlands (BritNed), Belgium (Nemo Link) and Norway (North Sea Link).

Between 2020 and 2030, National Grid expects its interconnectors to help the UK avoid around 100 million tonnes of carbon emissions, and by 2030, 90% of the energy imported through the company’s interconnectors will come from zero-carbon energy sources.

Earlier this year (2023), National Grid announced joint plans with TenneT for a new 1.8GW interconnector between the UK and the Netherlands called LionLink. The link would not only join the two countries but also connect to offshore wind generation. LionLink would be the second link between the two countries and is expected to be operational in the early 2030s. A second new link, called Nautilus, is also in the planning phase and could connect with Belgium. 

Original announcement: National Grid 
Image: Courtesy of National Grid

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