Project Type: Transmission reinforcement
Location: Highland, Moray

Contact Details

Liaison Manager

Lisa Marchi-Grey
Title: Community Liaison Manager
Telephone: 01463 728072
Mobile: 07825 015507
Address: 10 Henderson Road, Inverness, IV1 1SN

Land Manager

Ali MacLeod
Title: Land Manager
Mobile: 07500 912996
Address: 10 Henderson Road, Inverness, IV1 1SN
Status: Operational

Project Completion

Scottish and Southern Electricity Networks has now completed the construction, commissioning and energisation of the new Caithness-Moray electricity transmission link. Constructed over a period of four years, the link uses HVDC (High Voltage Direct Current) technology to transmit power through a 113km subsea cable beneath the Moray Firth seabed between new converter stations at Spittal in Caithness and Blackhillock in Moray. The project also involved work at eight electricity substation sites and has also required two overhead electricity line reinforcement projects. 


About the project

The Caithness-Moray submarine cable will use High Voltage Direct Current (HVDC) technology to transmit power beneath the seabed between converter stations at Spittal in Caithness and Blackhillock in Moray. This well established technology allows the efficient transmission of large volumes of electricity across long distances. Routing the cables across the Moray Firth rather than over land ensures greatly reduced visual impact. Reinforcement of the onshore transmission network between Dounreay and Mybster in the north and between Loch Buidhe and Beauly further south will also optimise the existing network in combination with the new cable.


Project elements

Along with the installation of the HVDC submarine cable itself, the project consists of four further core elements. These encompass work at eight substation sites, two converter stations and two overhead line reinforcement projects.

The data in this map is provided for indicative purposes only and may be subject to change. Scottish Hydro Electric Transmission plc do not accept responsibility for its accuracy, completeness or validity. The data should not be copied, reproduced or utilised externally without permission.

Who is Scottish and Southern Electricity Networks?

Scottish and Southern Electricity Networks is the trading name of Scottish and Southern Energy Power Distribution Limited, Scottish Hydro Electric Transmission plc, Scottish Hydro Electric Power Distribution plc and Southern Electric Power Distribution plc.

How are Transmission network upgrades paid for?

Investments in projects are made by SHE Transmission plc. Electricity transmission companies are authorised to recover the costs of such investments through 'use of system' charges which are levied by National Grid Electricity Transmission plc on generators and suppliers of electricity. Suppliers recover their costs from all electricity customers. In order to protect the interests of customers, the transmission companies have to demonstrate to the energy regulator, Ofgem (Office for Gas and Electricity Markets) that proposed investments are necessary, are efficient and are economical so that the charges which are ultimately levied on all electricity customers are justified.
This means SHE Transmission is subject to a funding mechanism established by Parliament and regulated by Ofgem. Cross subsidies between different businesses in the SSE group is not permitted.

How are proposals scrutinised?

The Scottish Ministers are responsible for determination of applications submitted under Section 37 of the Electricity Act 1989. Both statutory consultees and members of the public have the right to submit their representations on the application. All representations will be considered by Scottish Ministers in their determination of the application.
The Office for Gas and Electricity Markets (Ofgem), as the regulator, has to approve all investment so project proposals are developed under license conditions.
Preferred route corridors chosen will comply with revised ‘Holford Rules’ which are the recognised industry approach to routeing overhead lines amended to reflect Scottish circumstances.

What are The Holford Rules?

The Holford Rules originated in 1959 as the result of work by Lord Holford, a part-time member of the Central Electricity Generating Board (National Grid's predecessor). The Holford Rules have been augmented by both National Grid and SHE Transmission plc to reflect environmental legislation and best practice in recent years. We have continued to use them as a valuable set of guidelines for reducing the impact of our assets on landscapes.
The guidance recommends appropriate application of the Holford Rules to inform routeing. These rules advocate the application of a hierarchical approach to routeing which first avoids major areas of highest amenity, then smaller areas of high amenity, and finally considers factors such as backdrop, woodland and orientation. The Holford Rules apply the term ‘amenity’ to refer to environmental designations and classifications such as Natura 2000 sites, Sites of Special Scientific Interest (SSSI), Scheduled Monuments, Listed Buildings, National Parks.
The guidance also recognises that the key effect of overhead lines is visual and it advises that the routeing of overhead lines should consider the types of mitigation (screening) that could offset any visual effects.
In their National Policy Statement EN-5, the Government has stated that the Holford Rules “should be followed by developers when designing their proposals.” Their use is therefore Government policy, rather than a voluntary choice of SHE Transmission plc.

How and to what extent are electricity consumers' interests considered?

SHE Transmission are regulated by the Office for Gas and Electricity Markets (Ofgem), the regulator responsible for representing consumers' interests. Electricity consumer interests are therefore one of our key drivers and this is enshrined in our statutory duties under the Electricity Act.
In particular we have a statutory duty to develop, maintain and operate an efficient, economic and co-ordinated transmission system. Since the costs of these projects will ultimately be paid for by electricity consumers, we have a responsibility to take cost into account with due weighting in a comparison against other important factors.

What is the transmission network?

It’s the highest voltage electricity network in the UK – the ‘motorway network’ of the energy world. It transmits large quantities of electricity over long distances via wires carried on a system of mainly metal towers (pylons) and large substations. Transmission voltages in Scotland are 132kV, 275kV and 400kV. Larger generation schemes usually connect to the Transmission system.

The lower voltage parts of the system are called distribution networks. In Scotland, these local networks operate below 132kV whereas in England the distribution network includes 132kV. 

Completion of Caithness - Moray transmission link

Scottish and Southern Electricity Networks Transmission (SSEN Transmission), the wholly-owned subsidiary of SSE plc, has completed the construction, commissioning and energisation of the new Caithness-Moray electricity transmission link.

Caithness-Moray project: Tower being taken down near Thurso

As part of ongoing work on the Caithness-Moray transmission link, SSEN are currently dismantling the 89 transmission towers between substations at Dounreay and Spittal which are no longer in operation, following their replacement with new versions which are more robust and have a higher load capacity. Taking down a steel tower (which can weigh up to 10 tonnes) requires rigorous safety procedures to be in place at all times, a key one of which is the exclusion zone around the towers to prevent any unauthorised access. To see one of the towers near Thurso coming down, click on the photo to the right.

Half year results update

Colin Nicol, Managing Director of Scottish and Southern Electricity Networks, provides an update on the £1.1billion Caithness-Moray project.

Document downloads

Caithness Moray - Delivering economic and social benefits

Related Projects: Caithness - Moray

File Type: pdf
Published: 10 Nov 2016
Transmission reinforcement works in Moray

Related Projects: Caithness - Moray

File Type: pdf
Published: 18 Aug 2016
Caithness Moray Newsletter Caithness News 2016
File Type: pdf
Published: 30 Mar 2017

Local People

Lisa Marchi-Grey
  • Title: Community Liaison Manager
  • Email:
  • Telephone: 01463 728072
  • Mobile: 07825 015507
  • Address: 10 Henderson Road, Inverness, IV1 1SN
Ali MacLeod
  • Title: Land Manager
  • Email:
  • Mobile: 07500 912996
  • Address: 10 Henderson Road, Inverness, IV1 1SN

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