UK-Norway 1.4 GW interconnector passed the halfway point
of the world’s longest subsea power cable, between UK and Norway, has
now passed the halfway point. North Sea Link (NSL)
is a joint venture project between National Grid and its Norwegian counterpart
run from Blyth in Northumberland on the northeast coast of the UK to Kvilldal
in Rogaland on the Norwegian side. HVDC converter stations on each side
will connect the link to the onshore grid. The
1.4 GW interconnector will
allow the UK to import enough Norwegian hydro energy to power up to 1.4
Prior to cable-laying in Norway, the team had to build floating platforms
in lake Suldalsvatnet, which cannot be accessed by the cable laying vessel
due to its size.
The laying of 2.8km parallel subsea cables was executed from a 43 x 15
metre platform, at depths of up to 210 metres. Within 12 hours, cable
laying equipment was installed and 150 tonnes of cable were loaded on board.
Nigel Williams, Construction Director for National Grid North Sea link
commented, ‘The engineering that has taken place to lay high-voltage
cables below the seabed is remarkable. The difficult terrain, the depth
of the waters, and all in amidst of operating during a pandemic has made
it extremely challenging. Nevertheless, we have powered through and remained
on track with our project timelines.’
National grid has confirmed that the next step is to lay the cable out
from the fjords in Suldal, to the North Sea in summer 2020. Following this,
the two parallel 720km cables between Cambois, Northumberland in the UK
and Kvilldal in Norway will be completed by 2021.
Nexans was awarded a contract to supply the fjord, tunnel and lake sections,
as well as the onshore connection in Norway. The cables will be laid by
Nexans’ own cable-laying vessel, C/S Nexans Skagerrak, and protected on
the seabed by trenching with Nexans’ Capjet system and rock dumping.
will supply and install 950 km of submarine and land cables for the UK
and Norwegian North Sea sections of the route. The converter stations in
both the UK and Norway will be delivered by ABB.
will be operational by 2021.