North Sea Link AC

Project Details

Project Name: North Sea Link (NSL) AC
Asset Owner: NSL
GPS' Client: ABB
Completion: November 2020

Project Overview

NSN Link is a proposed high voltage direct current (HVDC) electricity interconnector with an approximate capacity of 1400 megawatts (MW). It will allow the transfer of electrical power between the UK and Norway, via subsea cables.The interconnector will be bi-directional allowing the import and export of electricity between the UK and Norway. 

The UK side of the NSL project comprises a direct buried cable route for the UK Land Section which is approximately 2.5km in length and will consist of two single core 525kV MIND cables which will be installed in the same trench from the Sea/Land Joint Bay to the new Convertor Station. The new HVDC Convertor Station will be delivered by ABB, and requires both internal DC Transformer to AC Hall connections, and AC Hall to NG Substation cable connections.

Scope of Works

GPS have been commissioned by ABB to provide a turnkey project management and system supply and installation package comprising of 4x 400kV AC cable circuits. Two circuits will connect the HVDC transformers to the AC switch hall AIS terminations within the new convertor station, and two longer circuits will connect the convertor station itself, to the new NG 400kV Gas Insulated Switchgear (GIS) substation extension. GPS will supply over 5.3km’s of cable from Sudkabel, together with all necessary accessories and strategic spares for the project. 

GPS is additionally providing:

• Cable drum logistics and delivery
• All necessary Project Management, technical/interface support
• Site establishment, welfare and CDM provisions
• All necessary Civil works, inclusive of working swath strip, construction corridor establishment, excavation,
  ducting, CBS and final reinstatement
• Required temporary works for civil elements and cable installation designs
• 12 x AIS termination support structure supply and installation

In addition to the above scope, ABB engaged with GPS to assist with completion of the remaining Civil work for the Convertor Station consisting of the following:

• Duct installation HV and LV
• Drainage installation and testing
• Construction of cable pits
• Grading off in preparation for finished floor levels
• Concrete installation including 400kV transformer plinths and soffits
• Landscaping works
• Site attendance team to assist management of site and de-watering
• All necessary Project Management and Civil Engineering support
• Installation of bio-efficient septic tank for the project site establishment
• Concrete finishing works