Project Type: Pumped hydro connection
Location: Highland

Contact Details

Liaison Manager

Sally Cooper
Telephone: 07918 470281
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: Project assessment

About The Project

SSEN Transmission have received a Transmission Owner Agreement to connect the Coire Glas Pumped Hydro Scheme for December 2027. The Scheme will be the first large-scale pumped storage scheme to be developed in the UK for more than 30 years and has a potential capacity of up to 1500 Megawatts (MW). This supports the UK move towards a net zero carbon energy system by 2050.  A degree of rationalisation of the existing infrastructure will form part of these works.

The scheme is located southwest of Laggan Locks, near to Loch Lochy, Highland.  The connection is for a total of 1296MW Export/1360MW Demand and will be carried out in two phases. 

Phase 1 will see the connection of 612MW Export/660MW Demand in December 2027

Phase 2 will see the connection of a further 684MW Export/700MW Demand in October 2029.

Project Elements

Phase 1 Project Elements (Connection December 2027)

  • A new Coire Glas 400kV external Air Insulated Switching Station (AIS), this will include 2 control buildings.
  • Approximately 3.5km of 400kV overhead line. This will be installed from the proposed Coire Glas switching station to a new substation located in the vicinity of Loch Lundie.
  • A new 400/132kV substation in the vicinity of Loch Lundie. This will comprise a control building, 2 transformers and outdoor AIS equipment.
  • Approximately 8.5km of 400kV of overhead line. This will be between the proposed Loch Lundie substation to the existing Fort Augustus substation at Auchterawe.


Phase 2 Project Elements (Connection October 2029)
There will be no further development work in the Fort Augustus area as part of this project.

The works will include;

  • the upgrade of the Beauly-Denny overhead line second circuit to 400kV operation.
  • construction of the Eastern HVDC Peterhead – Drax Link.

A map showing some of the options currently being assessed can be viewed on the Project Documentation page.

Community Engagement

Throughout the life of our projects, we aim to work positively with local communities and keep people informed about what we are doing. This is particularly important when we are developing a project and we want to understand what local people think about our plans. We endeavour to take the time to discuss our proposals with local community councils and the wider affected community and to carry out engagement at key stages, listening to feedback before finalising project plans.

We will be holding public consultation events in Spring 2022. For these we will welcome community members and all interested parties to visit either one of our face to face events or to attend one of our virtual online consultations to see our project proposals and to give feedback and ask any questions about the Coire Glas connection project.




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. 

Map Showing Some Considered Options

Map Showing Some Considered Options

Related Projects: Coire Glas Connection Project

File Type: pdf
Published: 25 Nov 2021

Local People

Sally Cooper
  • Email:
  • Telephone: 07918 470281
  • Address: 10 Henderson Road, Inverness, IV1 1SN

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