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.

Public information exhibition

You can see more detail on our proposed project by viewing our digital exhibition. 

Click here to view it

What we plan to build

We are proposing to build and connect 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 also plan to install an underground cable from the coastline just north of Seaham, to the new converter station and substation at Hawthorn Pit.

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 SP Energy Networks.

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. 

Underground cable

This image shows what the cable looks like. 

The proposed 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.

Where we propose building SEGL1 

If approved, SEGL1’s cable will make landfall at north of Seaham. The cable will then run underground for approximately 10km before connecting to the national grid network at Hawthorn Pit, in between the villages of Murton and South Hetton.


When will the work happen?

If approved, construction is expected to begin in 2024 and finish in 2027.

We held our public consultation in spring 2021 and public information events in early 2022. Our next step will be the submission of our planning application, which we expect will happen in spring 2022.

click timeline to enlarge