Project Type: Transmission reinforcement
Location: Western Isles

Contact Details

Liaison Manager

Lisa Marchi
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: Early Development

Project overview

The development of onshore renewables on Lewis, particularly in the onshore wind sector, has driven a requirement to reinforce the electricity transmission network on the island.

Key benefits of these works will include the facilitation of connecting local renewables, planned and future, onto the network, as well as improving the security of the electricity network on Lewis.


To support the connection of the Uisenis Wind Farm, located to the south of Stornoway, the following works have been identified:

  • The construction of approximately 25km of new 132kV overhead line (OHL) to replace the existing line linking Lewis and Harris.
  •  The construction of a new Gas Insulated Switching Station near Balallan, to facilitate the connection of the Uisenis wind farm onto the electricity transmission network.
  • The removal of the existing 132kV OHL between Balallan and Stornoway Grid Supply Point.
  • Connections of the OHL at Balallan, Stornoway Grid Supply Point and the new Arnish substation.

Why is the project required?

The works are required to meet the needs of renewable developers on Lewis looking to connect to the GB Transmission System and form part of SSEN’s proposed  transmission link from the Western Isles to the Scottish mainland.


An overview of our route and switching station

The adjacent video, which has been designed by specialist company 3D Webtech, allows viewers to see what the Balallan 132kV switching station and Balallan - Stornoway 132kV overhead line replacement would look like. This video has been created to increase the transparency of our plans and was on display at the public exhibition held in Stornoway in 2018.


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To make use of this function please click on the 'accessibility' button at the top right of the website. 

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.

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. 

Consultation Event

SSEN is today hosting a consultation event to discuss proposals for a new 132kV Switching Station near Balallan and replacement overhead line between Balallan and Stornoway. The event will be held at Kinloch Historical Society, Balallan between 15:00 - 19:00. This is an open door event and we would encourage any interested stakeholders or community members to come along, meet the team and find out more about the proposals.

SSEN - Balallan to Stornoway Event - 16pp Brochure

Related Projects: Balallan Switching Station and 132kV OHL

File Type: pdf
Published: 12 Sep 2018

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