North Sea Link
OperationalCross Border
GBNO
1,400 MW525 kV720 km2021Basic information
8 fieldsAlso Known As
NSL · NSN · NSN ("North Sea Network") · NGN Link · NESO TEC PRO-000975
Status
operational
Capacity
1,400 MW
Project Company
Type
cross border
Expected Life
25 years
Website
Supply Chain (12)
Project Timeline (35)
2023Grid Constraint Event
In 2023 the North Sea Link’s licensed maximum transfer capacity was reduced from 1,400 MW to 1,100 MW under licence conditions. The reduction constrained the bi-directional transfer capability of the UK–Norway HVDC interconnector, lowering available cross‑border capacity and reducing the link’s potential to support price convergence between the two markets during tight system conditions. The restriction stemmed from licence/regulatory conditions rather than a one-off outage and remained a defining operational constraint for the link in 2023.
29 Sept 2023Revenue Secured
Ofgem issued its Post Construction Review decision for the North Sea Link (NSL) interconnector, confirming final values for the project’s cap-and-floor revenue regime. The Authority determined the Post Construction Adjustment terms and set final annual cap and floor levels (2015-16 prices) for NGNSL’s 50% share: a cap of £93.3m and a floor of £59.3m (PCAC £3.5m; PCAF £8.4m). The decision also published modified licence special conditions and final versions of the NSL Cap and Floor Financial Models to govern revenue assessment during operation. The decision followed NGNSL’s PCR submission and consultation earlier in 2023 and applied to revenues in the operational assessment periods after the project entered service.
11 May 2022Revenue Secured
Ofgem approved National Grid’s proposal to accelerate payments of interconnector revenues to consumers, enabling National Grid to make £200m of interconnector revenue payments earlier than under the standard five‑year assessment cycle. The announcement listed NSL among National Grid’s interconnectors covered by the cap-and-floor framework; the approval changed the timing of revenue flows rather than altering NSL’s cap or floor levels.
14 Feb 2022Construction Other
Prysmian received the project Completion Certificate on 14 February 2022 after delivery of commissioning activities and as‑built documentation, signalling formal completion of its installation scope on North Sea Link. The supplier stated the project was completed ahead of schedule following execution of jointing, commissioning and documentation handover.
14 Feb 2022Late Development Other
Prysmian Group received the Completion Certificate for the North Sea Link installation on 14 February 2022, marking the formal completion of the installation phase. Prysmian reported that installation works had finished ahead of schedule, commissioning and trial activity had been carried out in late 2021, and the project entered final acceptance steps following the certificate issuance.
Dec 2021Revenue Application
National Grid NSL submitted its Post Construction Review (PCR) package in December 2021 proposing values for the Post Construction Adjustment (PCA) terms and updated project cost information. This submission initiated Ofgem’s PCR process to assess final project costs and to determine any adjustments to preliminary cap and floor levels, leading to subsequent cost updates (Dec 2022, Mar 2023) and the 2023 decision.
2021System Testing
The National HVDC Centre performed protection coordination testing for North Sea Link in a real‑time Hardware‑in‑the‑Loop simulation environment prior to energisation. The tests used RTDS® and power amplifiers with models of the NSL interconnector (provided by ABB), series compensation, and nearby AC network/protection relays to validate relay settings and identify required protection coordination changes before the link connected to the GB transmission network.
1 Oct 2021Onss Commissioned
The North Sea Link interconnector — a joint venture between National Grid and Statnett — was commissioned and entered into trial/commercial operations on 1 October 2021. The commissioning completed the converter station and onshore substation works that enabled electricity transfer between Kvilldal (Norway) and Blyth (UK). The link began a controlled ramp-up of capacity (starting at up to 700 MW and increasing toward the 1,400 MW design over a subsequent three-month period) to validate operational performance and grid integration prior to full commercial operation.
1 Oct 2021System Testing
Trial operation of North Sea Link began on 1 October 2021 (from 09:00 CET), during which the asset transferred electricity between Norway and Great Britain while operators validated market and operational processes in close‑to‑normal conditions. The three‑month trial allowed gradual capacity increases and provided data to confirm operational performance, market integration and system security prior to sustained commercial use.
1 Oct 2021Commercial Operations Full Power
National Grid and Statnett announced that North Sea Link began commercial operations on 1 October 2021. The partners stated the interconnector entered commercial service starting at a maximum of 700 MW and would be gradually increased to its designed 1,400 MW over an approximately three-month commissioning period. Trading was conducted via the appointed power exchange (Nord Pool/EMCO) so that GB and Norwegian markets could exchange energy; the commercial start enabled cross‑border renewable energy trade and system‑security benefits for both countries.