The UK and Norway can now share renewable energy for the first time following the commissioning of the world’s longest sub-sea electricity interconnector. The nationalgrid.com/group National Grid’s 1.6 billion euro North Sea Link (NSL), a joint venture with Norwegian system operator Statnett, started commercial operations at the beginning of October and has taken six years to build.

Laying of the undersea cables began in 2018 and more than 4 million working hours have been spent on the project, including 5,880 working days at sea.

The 450-mile cable, which connects Blyth in Northumberland with the Norwegian village of Kvilldal, near Stavanger, started with a maximum capacity of 700MW and will gradually increase to the link’s full capacity of 1,400MW over a three-month period.

Once at full capacity, NSL will provide enough clean electricity to power 1.4 million homes; it will also be the fifth interconnector for National Grid, which also operates links to Belgium, France and the Netherlands. By 2030, 90% of electricity imported via National Grid’s interconnectors will be from zero-carbon sources.

Norwegian power generation is sourced from hydropower plants connected to large reservoirs, which can respond faster to fluctuations in demand compared to other major generation technologies. However, as the water level in reservoirs is subject to weather conditions, production varies throughout seasons and years.

When wind generation is high and electricity demand low in Britain, NSL will enable renewable power to be exported from the UK, conserving water in Norway’s reservoirs. When demand is high in Britain and there is low wind generation, hydro power can be imported from Norway, helping to ensure secure, affordable and sustainable electricity supplies for UK consumers.

Cordi O’Hara, president of National Grid Ventures, said: “This is an exciting day for National Grid and an important step as we look to diversify and decarbonise the UK’s electricity supply. North Sea Link is a truly remarkable feat of engineering. We had to go through mountains, fjords and across the North Sea to make this happen; NSL is also a great example of two countries working together to maximise their renewable energy resources for mutual benefit.”

Hilde Tonne, Statnett’s CEO, said: “The sharing of renewable energy between countries and regions is a prerequisite for delivering a ‘net zero’ future for everyone. As NSL goes into trial operations, I am proud of the engineering feat produced by our joint team.”