Onshore Construction


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 onshore converter station in June 2021.



Work is now underway to prepare for the start of construction of the onshore electrical infrastructure for Sofia. Known as the enabling works - civil engineering contractor Jones Bros moved onto the site in June 2021. The Jones Bros. works will include 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.

Earlier in the year contractors working for Sembcorp diverted potable and raw water pipes around the converter station site, and at the same time confirmed the location of other buried services likely to be affected by the construction. This Sembcorp work is now completed and included excavation and pipe laying on the plot of land between the existing mounds near Lazenby and the Wilton South Gate entrance.

Some vegetation clearance was undertaken as part of the water pipe diversion works and further vegetation clearance was required to make way for the creation of a temporary access road to the south east of the site, temporary construction compounds and part of the haul road.


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