Final cable laid for world’s longest subsea electricity link
Work to lay a 450-mile (720km) subsea electricity cable between the UK and Norway is now complete.
The final section of National Grid’s North Sea Link (NSL) interconnector was laid this week, meaning the two countries are now linked for the first time.
Due to become operational on 1st October, NSL will be the longest subsea electricity cable in the world, able to transport enough clean energy to power up to 1.4 million homes.
Laying of the cables, which links Blyth in Northumberland to the Norwegian village of Kvilldal, began in 2018. Almost four million working hours have been spent on the project to date.
NSL, a joint venture between National Grid and Norwegian system operator Statnett, will enable the direct sharing of renewable energy between the UK and Norway for the first team.
Earlier this week, the final stretch of the cable was jointed by specialists on a cable-laying vessel almost 300 miles (465km) from Blyth and 93 miles (150km) from Stavanger in Norway.
The completion final transition joints is a complex and specialised activity. Each joint is undertaken manually, with the process taking around seven days and involving continuous work from a specialist jointing team comprising 12 people.
It involves lifting two sections of cables onto the vessel and peeling back each of their many layers before carefully joining them together by hand. The newly jointed cables are then returned to the seabed and buried beneath the surface for added protection
Members of the project team and partners including Nexans and Prysmian have spent a total of 5,880 days at sea working on various stages of the project including cable laying, trenching and burying.
Nigel Williams, North Sea Link Project Director for National Grid, said: “North Sea Link is a remarkable feat of engineering, but more importantly, it represents two countries working together to maximise their renewable energy resources for mutual benefit. Between the start of operation and the end of the decade, we estimate that NSL will save 23,000 million tonnes of carbon – making it a key tool in the UK’s journey to net zero.”
Thor Anders Nummedal, North Sea Link Project Director for Statnett, said: “The laying of the final cable is a key moment in what has been a long and incredible journey. The exchange of green energy enabled by North Sea Link will strengthen security of supply, because we can import electricity when the system is tight in Norway. It also provides increased value creation for Norway through the export of surplus electricity and allows us to maximise the use of every spare electron of renewable energy.”
North Sea Link will be National Grid’s fifth interconnector with links to France, The Netherlands and Belgium already in operation. In 2024 the company will launch its sixth Interconnector to Denmark which will be able to import and export enough power for a further 1.4 million homes.
By 2030 90% of all power coming into the UK via interconnectors will be from zero carbon sources.