Onshore Construction

This page features the latest updates on Sofia's onshore construction progress and upcoming activity, as well as details of the main contractors that will ensure the successful delivery of  the project's onshore electrical infrastructure, from landfall to the National Grid substation.


Onshore Map


The power produced by Sofia will be transmitted by offshore cables that arrive on land at a site between Redcar and Marske-by-the-Sea. Each offshore cable will connect to an onshore buried cable that will run seven kilometres to a new converter station to be constructed on a site adjacent to the Wilton Complex. Further buried cables will transport the power two kilometres from the converter station to the existing substation at Lackenby, where it will feed into the national grid. Onshore construction works began at the site of the converter station in June 2021, and onshore project-related activity will continue until early 2025.


Work by civil engineering contractor Jones Bros. Civil Engineering UK to prepare for the start of construction of the onshore electrical infrastructure for Sofia is now complete with the site handed over to GE’s Grid Solutions and their onshore converter station sub-contractor Kier Infrastructure. The Jones Bros. activity included providing a level load-bearing stone platform for both the Sofia and neighbouring Dogger Bank C converter stations; two new accesses to the site with associated bellmouths; welfare and laydown areas; drainage system, and associated utilities. Regular drone filming has captured the progress of the works and will continue as the onshore converter station takes shape.

In terms of local impacts, Sofia is keen to minimise disruption to those living nearest the site and part of this has focussed on re-shaping the mounds that separate the converter stations’ site from Lazenby Village. The reshaped mounds will be an improved barrier to the construction activity and in the longer term they will visually screen the two new converter stations and the Wilton International site. The first phase of work is now complete, with the north mound reshaped and planted with trees, shrubs and wildflowers. The second phase of reshaping, on the southern mound, will get underway in 2022.

Work has begun on the onshore civil engineering work for the export cable route following the appointment of J. Murphy & Sons Ltd.


Mid 2021

Start of enabling works to prepare for the construction of the converter station.

Start of work on the mounds on-site - to increase the screening of the converter station site from the village of Lazenby.

Late 2021

Enabling works completed at the converter station site.

Work at the existing National Grid Lackenby Substation begins.

Early 2022

Construction of Sofia’s onshore converter station begins.

Start of works along the cable corridor from landfall to Lackenby Substation. Trenching and duct laying underway.

Mid 2022

Start of two years construction activity at the landfall between Redcar and Marske-by-the-Sea, including horizontal directional drill under the beach to lay ducts for the offshore cable.

Early 2023

Start of installation of the cables from shore to the converter station and from the converter station to the substation.

Mid 2023

Completion of work along the cable corridor from the converter station site to the substation.

Mid 2024

Completion of construction works at the landfall site.

Completion of the installation of cables from shore to the converter station.

Late 2024

Sofia connected to the national grid. All work, including reinstatement, completed along the cable corridor between the converter station and substation, and at the substation itself.

Onshore converter station construction completed.

Completion of the mounds screening the converter stations.

Early 2025

Completion of reinstatement of cable corridor from shore to the converter station site.


All relevant plans relating to the project's onshore construction, including Design, Landscape, Fencing and Drainage, will be submitted to Redcar & Cleveland Borough Council for approval prior to work starting. The button below takes you to a list of all the available documents and their reference numbers so you can find them in the Planning Register of the Council website.



Starting onsite in 2022, GE's Grid Solutions will be responsible for the construction of the onshore converter station.

GE's Grid Solutions

Prysmian Group will design, supply, install and commission Sofia's HVDC export link including 15km of onshore cables and installation work.


Prysmian Group


Jones Bros Civil Engineering UK will deliver the enabling works package for the onshore converter station platforms for both Sofia and Dogger Bank C.

Jones Bros. Civil Engineering

Kier is carrying out the onshore converter station civils construction package on behalf of GE's Grid Solutions.


VolkerInfra will design, supply and install the 400kV AC cable between Sofia's onshore converter station and National Grid's Lackenby Substation.


BakerHicks will design the Sofia onshore converter station and carry out related activities.


J. Murphy & Sons will design and deliver the onshore export cable civil works in relation to both Sofia and neighbouring project Dogger Bank C.

Murphy Group