Who are SSEN Transmission?

Scottish and Southern Electricity Networks Transmission (SSEN Transmission) are responsible for the electricity transmission network in the north of Scotland, maintaining and investing in the high voltage 132kV, 220kV, 275kV and 400kV electricity transmission network. They are the electricity transmission subsidiary of SSE plc.

As a natural monopoly, SSEN Transmission are closely regulated by the GB energy regulator, Ofgem.

SSEN Transmission's network consists of underground and subsea cables, overhead lines on wooden poles or steel towers, and electricity substations. It extends over a quarter of the UK’s land mass, crossing some of its most challenging terrain.

SSEN Transmission's priority is to provide a safe and reliable supply of electricity to communities. They do this by taking the electricity from generators and transporting it at high voltages over long distances through a transmission network for onward distribution to homes and businesses in villages, towns and cities.

SSEN Transmission are owned 75% by SSE plc and 25% by Ontario Teachers’ Pension Plan Board.

SSEN Transmission in numbers

+
employees
+
jobs supported across the UK
GW
of renewable energy generation connected to the network
£ bn
worth of investment committed this decade
> %
net gain in biodiversity across all projects
new jobs to be created Nov 23 - Nov 24
£ m
committed to a community benefit fund
net-loss of woodland from all new projects

SSEN Transmission's projects

Filter sites

Spittal – Loch Buidhe – Beauly 400kV Connection

A new Beauly 400kV substation is needed for the connection of the Spittal, Loch Buidhe, Beauly 400kV overhead line and the Beauly, Blackhillock, New Deer, Peterhead 400kV overhead line. This new substation will be located near to the existing Beauly substation.

Spittal – Loch Buidhe – Beauly 400kV Connection

Spital 400kV Substation

A new Spittal 400kV substation is essential to facilitate connections of the Spittal, Loch Buidhe, Beauly 400kV overhead line and the Spital to Peterhead HVDC subsea cable link. A HVDC (high voltage direct current) converter station is also required in the vicinity of the new Spittal substation site as part of the wider subsea link project.

Loch Buidhe 400kV Substation

To connect the new Spittal - Loch Buidhe - Beauly 400kV overhead line, a new 400kV substation is required near the existing 275kV substation at Loch Buidhe. The new 400kV substation will also require a connection to the existing 275kV substation.

Loch Buidhe 400kV Substation

Spital to Peterhead HVDC Subsea Cable Link

In addition to the new onshore overhead line and substation projects, a new HVDC (high voltage direct current) subsea link between Spittal and Peterhead is also necessary to support the growth of renewable energy. The HVDC link will allow surplus renewable energy to be exported south to Peterhead without the need for a second onshore 400kV overhead line.

Blackhillock 2 400kV Substation

To enable new reinforcements, a new 400kV substation is required in Blackhillock and will connect Beauly Blackhillock New Deer Peterhead 400kV Overhead Line Project.

Blackhillock 2 400kV Substation

New Deer 2 400kV Substation

SSEN Transmission has plans to construct a new 400kV substation in New Deer. They have undertaken system and technical analysis to ensure that our proposals meet the future requirements of the network. The new station will enable increased generation in the North-East of Scotland to connect to the Transmission network.

New Deer 2 400kV Substation

Beauly HVDC Converter Station

A HVDC (high voltage direct current) converter station is also required in the vicinity of the new Beauly substation site as part of connecting the Western Isles to the transmission network on the mainland. The converter station will connect to the new substation before connecting to the existing Wester Balblair Substation.

Beauly HVDC Converter Station

Western Isles Connection

The subsea cable from the Western Isles is due to land at Dundonell on the west coast of Scotland. From there, around 80km of underground high voltage direct current (HVDC) cable will be required from Dundonnell to the proposed HVDC converter station at Beauly, before connecting into the new Beauly substation.

Western Isles Connection

Beauly to Denny 400kV Second Circuit Uprating

This project will see the second circuit on the existing Beauly - Denny Overhead Line being upgraded from 275kV to 400kV, to connect new renewable energy generation to the transmission network in the coming years. On completion, both circuits will operate at 400kV and SSEN Transmission do not anticipate any alterations to the existing overhead line in order to upgrade it.

Beauly to Denny 400kV Second Circuit Uprating

Peterhead 400kV Substation (Peterhead 2)

A second 400kV substation is required in the Peterhead area to support offshore and onshore electricity generation connections as well as onshore and offshore transmission infrastructure in the area. The substation will be similar to the first 400kV substation which is due to be commissioned in 2023.

Peterhead 400kV Substation (Peterhead 2)

Kintore-Tealing 400kV OHL Connection

30-35km of new 400kV overhead line between the existing Kintore site to a new 400kV capable substation within the vicinity of the existing Fetteresso substation. An extension to the 400kV substation at Kintore which is currently under construction. 60-70km of new 400kV overhead line between the new proposed Tealing and Kintore substations.

Kintore-Tealing 400kV OHL Connection

Hurlie 400kV Substation

A new 400kV capable substation within the vicinity of the existing Fetteresso substation.

Hurlie 400kV Substation

Tealing (Emmock) 400kV Substation

A new proposed 400kV capable substation within the vicinity of the existing Tealing substation.

Tealing (Emmock) 400kV Substation

Alyth – Tealing Overhead line Reconductor

Upgrade to 400kV capability by reconductoring the existing Alyth – Tealing 275kV overhead line. When the Alyth – Tealing and Tealing – Westfield/Glenrothes lines are upgraded to 400kV they will be connected into the new Tealing 400kV site.

Alyth – Tealing Overhead line Reconductor

Tealing – Westfield Overhead line Reconductor

Upgrade to 400kV capability by reconductoring of the existing Tealing – Westfield/Glenrothes 275kV overhead line down to the Scottish Power Transmission (SPT) border. SPT will continue the works on their section of overhead line within the relevant license area.

Tealing – Westfield Overhead line Reconductor

Eastern HVDC Link (Eastern Green Link 2)

SSEN Transmission are installing 2GW subsea high voltage direct current (HVDC) cable link from Peterhead to Drax in Yorkshire. This will help to reduce congestion on the onshore transmission network by allowing the flow of energy through the subsea cable. This project is being jointly developed with National Grid Electricity Transmission.

Eastern HVDC Link (Eastern Green Link 2)

Peterhead to South Humber HVDC Link (Eastern Green Link 3)

A 2GW, 525kV subsea high voltage direct current (HVDC) link between Peterhead and South Humber in England is required to enable the transmission from generators in the northeast of Scotland to demand centres in the south of England. The link will require 2 HVDC converter substations on land, one at each end of the cable.

Peterhead to South Humber HVDC Link (Eastern Green Link 3)

Peterhead HVDC Switching Station

Due to the high number of subsea links, and the potential need to support future offshore customer connections, system studies have informed the need for a Direct Current Switching Station (DCSS) at Peterhead. This project aims to deliver a 525kV DCSS, which is needed to coordinate the connection of offshore links and windfarms and will connect into the New Peterhead 400kV substation.

Peterhead HVDC Switching Station

Peterhead 132kV Substation

A second 132kV substation is required in the Peterhead area to support future generation and storage connections from renewable generation developers. The substation will be similar to the existing 132kV substation.

Peterhead 132kV Substation

Peterhead 275kV Substation Refurbishment

Due to their condition, there is a requirement to replace the Super Grid Transformers (SGT), SGT1 and SGT2 at Peterhead 275/132kV substation. Transformers step up or step down the voltage of electricity between different circuits within our substations. Two new buildings will be created to house the new SGTs within a new compound to the southwest of the existing substation.

Peterhead 275kV Substation Refurbishment

SSEN Transmission's RIIO-T2 business plan

Transport the renewable electricity that powers 10 million homes

Every connection delivered on time

Aim for 100% transmission network reliability for homes and businesses

One third reduction in our greenhouse gas emissions

£100 million in efficiency savings from innovation