Active the world’s longest underground submarine interconnector

The Viking Link interconnector has a capacity of 1.4 GW

With a length of more than 764 kilometers covered under the surface of the earth and the sea, the Viking Link project has been awarded since the design phase the title of the longest electric interconnector in the world. But for the record to be true it had to wait for 29 December 2023, the date of the beginning of commercial operations. To give news of the operation is National Grid, an energy company operating in the United Kingdom and the United States, and has realized the work in a joint venture with the Danish TSO Energine. The infrastructure connects the electrical systems of Great Britain and Denmark, linking the Bicker Fen substation in Lincolnshire with the Revsing substation in southern Jutland. The objective of the project? Allow more efficient use of renewable energy, access to sustainable electricity production and increased security of electricity supply. With socio-economic benefits for both countries.

How does the Viking Link interconnector work?

Equipped with a capacity of 1.4 GW, the new interconnector is nothing more than a high-voltage direct current (DC) electrical connection. The infrastructure has an offshore portion buried in the seabed 620 km long and an onshore that also includes conversion stations (CC-CA) and underground cables in alternating current (AC) that reach the substations. Construction of Viking Link – National Grid’s sixth interconnector – began in 2019 and the last practical tests were carried out in August 2023. The cable was tested at 735,000 volts, equivalent to 1.4 times its operating voltage of 525,000 volts, proving perfect operation.

Today, however, it has not yet reached full operation. For now, the connection infrastructure will work with a capacity of 800 MW before increasing up to 1.4 GW. Both companies said they were working to bring the plant to full capacity this year. “This new record-breaking link – said Katie Jackson, president of National Grid Ventures – is a fantastic example of engineering and collaboration with our partner Energinet”. “Extending over land and sea more than any of our existing connections, it connects the UK to Denmark’s clean and ecological energy, […] bringing huge CO2 savings and money to UK consumers”.

In early 2013, National Grid announced joint plans with TenneT for a new 1.8 GW interconnector between the UK and the Netherlands, called LionLink. The link would not only link the two countries, but would also link to the wind farms in the marine space between the two. In addition, a new connection, called Nautilus, for the electrical connection with Belgium is being designed. “As we use more wind energy to achieve our climate and energy goals, connections with neighboring countries will play a vital role in increasing security of supply and lowering prices for consumers,” Jackson added.