'World's longest DC cable' to connect Denmark and UK

EUROPE: The Danish minister for energy, utilities and climate has approved funding for a power cable, more than 750km long, linking Denmark and the UK.

The Viking Link would stretch more than 750km between the UK and Denmark

The Viking Link, a joint project to be carried out by Danish transmission system operator Energinet and the UK's grid operator National Grid, would cost approximately DKK 11 billion (€1.48 billion).

It is believed to be the world’s longest direct current cable (DC), the Danish energy ministry stated.

The cable would stretch from Revsing in the south of Denmark to the UK's national grid substation at Bicker Fen in east England.

The UK connection point is also where power from Innogy's 860MW Triton Knoll offshore wind project is to be connected to the UK’s grid.

The interconnector will have be able to transfer 1.4GW of electricity, the Danish energy ministry added — a little more than a third of the country’s average electricity consumption. Viking Link is expected to be operational by the end of 2022.

Denmark’s energy minister Lars Christian Lilleholt said: "Strong electrical connections abroad are crucial for a small nation like Denmark.

"We get the opportunity to sell our power to a bigger market when we have a surplus of renewable energy. At the same time we get a greater supply of power to Denmark when the wind does not blow and the sun does not shine.

"(This will enable us to supply) strong electricity to our neighbours, thus contributing both to ensuring affordable and reliable power to consumers, and to keeping the wind power value up," Lilleholt added.

The Viking Link would create a security of supply in both Denmark and the UK, increase the value of wind power, create more opportunities to trade electricity across borders, and help meet international and national targets for renewable energy and CO2 emissions, the Danish energy ministry added.

High-voltage direct current (HVDC) cables, 635km long, will be buried in the seabed between the UK and Denmark.

In the east, HVDC cables will stretch from the Danish west coast alongside roads to a 400kV substation in Revsing. There, the current will be changed from direct current to alternating current (AC). 

Meanwhile, a similar process will take place in the UK. HVDC cables will transfer power from the English east coast approximately 50km to a substation in Bicker Fen, where the current will be changed from DC to AC for integration to the grid.