Delivering a cleaner, greener future

The UK is committed to achieving net-zero greenhouse gas emissions by 2050 and, as the country moves away from traditional fuel sources like coal and oil to heat homes and power vehicles and businesses, we will need more renewable power like green electricity.

The construction of SEGL1 and its sister project, SEGL2, will create two High Voltage Direct Current (HVDC) electricity ‘superhighways’ from Scotland to England. 

SEGL1 will run from the Torness area in East Lothian to Hawthorn Pit (between Murton and South Hetton) in County Durham, via the North Sea. 

Both SEGL1 and SEGL2 are essential to meet the UK’s net zero commitments and deliver a cleaner, greener future.

What we plan on building


We are planning on building and connecting a new converter station and substation near to our existing substation in Hawthorn Pit, which is between Murton and South Hetton, in County Durham.

We expect to submit these applications to Durham County Council for approval in winter 2023/2024.

You can explore our approved outlined planning application by visiting the Council’s planning portal and inputting our application’s reference number: DM/22/01663/OUT.


Converter station and substation

Our converter station will house the technology to enable the green electricity to be transmitted through the approximately 190km cable.

A converter station converts electricity between Alternating Current (AC) and Direct Current (DC). AC is used in each country’s transmission system, while DC is used for sending electricity long distances along the subsea cables. A similar converter station will be constructed at the other end of the cable in the Torness area, and this is being consulted on by SPEN.

Substations are crucial for controlling the voltage of electricity between the country-wide network and people’s homes and businesses. They ‘step down’ the high-voltage electricity running up and down the country to lower voltage electricity suitable for everyday use.

Below is how we are planning to lay out our converter station and substation, as well as a new public space at Hawthorn Pit.

Please click on the map below for a detailed view of the site layout.


Landscaping and new public space at Hawthorn Pit

As part of our planning application, we submitted an outline mitigation plan which sets out how we aim to better integrate the new converter station and substation into their surroundings, improve biodiversity and establish a space open to the public.

Please click on the image below for a detailed view of the plans.


Underground cable

Our cable route for SEGL1 runs under the North Sea for most of its approximate 190km length.

After travelling under the sea from the Torness area, it will come ashore just north of Seaham. The cable will then run underground onshore for around 10km, to the new converter station and substation at Hawthorn Pit.

Please click on the below images for detailed plans of the route, from the landfall point just north of Seaham to our converter station and substation at Hawthorn Pit.

The plans include a detailed view of the proposed cable route, road crossing methods and the locations of the temporary construction compounds and access roads that would be used during the installation of the cable.


Planning permission for the offshore section of the cable

The project has also submitted a marine licence application to the Marine Management Organisation and Marine Scotland for SEGL1’s 176km submarine cable, the offshore element of the project.

Much like planning permission onshore, this process involves a period of technical appraisal and consultation which will inform the outcome of the application.

The marine licence application can be viewed in the public register using the reference number MLA/2022/00231.

If you have any questions about the above plans, please get in touch via email at [email protected] or telephone on 0808 196 8405.

When will the work happen?

We have now received approval for our planning application from Durham County Council for the onshore elements of the project. If all our project’s consent applications are approved, we expect to begin construction in autumn 2024 and finish in 2027.

click timeline to enlarge