New Coire Mashie 400kV Substation and Earba PSH Connection

Report on Consultation

Our Report on Consultation for the new Coire Mashie Substation and Loch Earba Pumped Hydro Scheme Connection has now been published.

The report provides a summary of the extensive feedback received during the consultation period, outlines how this feedback has been considered, and confirms that the substation site Option 1 will be taken forward to the next stage of development. While all of the appraised site locations presented a range of environmental and engineering challenges, the challenges associated with Option 1 were considered manageable and capable of being addressed through further design and mitigation work.

The Report on Consultation (RoC) can be downloaded from the Documents tab on our project website. All stakeholders who have registered for project updates will also receive a direct link to the report. New Coire Mashie 400kV Substation and Earba PSH Connection - SSEN Transmission

We would like to thank all stakeholders who took the time to engage with our early consultation process. Your feedback has been invaluable in shaping the proposals to date.

Publication of the RoC marks the completion of the first round of non-statutory consultation, during which we sought views on the proposed route for the 400kV connection, and substation locations. We will continue to engage with stakeholders ahead of further community consultation in the new year, as we work to refine our proposals.

We welcome ongoing dialogue and would like to reassure stakeholders that there will be further opportunities to engage as the project progresses.

3D Visualisations Portal 

To help provide a better indication of the site options for the proposed Coire Mashie substation within the local setting, we've created a 3D visualisation portal. The portal can be accessed via the link below, where you can view various viewpoints from across the proposed development.

It should be noted that the substation shown in the photospheres is indicative and subject to change following development and refinement of the substation design. There is no screening shown in the photospheres; however, this will be considered as the design develops.

Visit the 3D visualisations portal

About the Project

New Coire Mashie 400kV Substation 

The new 400kV substation required near Ardverikie Estate and Kinloch Laggan in the Highlands of Scotland to allow the connection of Earba Pumped Storage HydroScheme to the National Grid. 

The new substation would also be: 

• Required to connect into the existing Beauly-Denny overhead line.
• Sited relatively close to the existing Beauly-Denny overhead line to limit the additional infrastructure required.

New Earba 400kV Underground Cable 

The Earba Pumped Storage Hydro Scheme requires connection to the National Grid. To facilitate this, a new400 kV underground cable is proposed. 

The new underground cable would be: 

• Connected from Earba Pumped Storage Hydro Schemes on-site powerhouse located by the Southeast shore of Loch Earba to the new proposed Coire Mashie Substation.
• Approximately 15km in length depending on the route option that is chosen following consultation. We will be able to provide more information regarding the underground cable route once the location for the new 400kV substation has been determined following consultation with local community members and statutory stakeholders.

Why is the Project Required?

SSEN Transmission is required to connect to the proposed Earba Pumped Storage Hydro (PSH) Scheme with an installed capacity of up to 1,800MW. 

Under our Network Operators Licence we are required to deliver the connection in a technically efficient, co-ordinated and economic manner, whilst having the least practicable impact on people and the environment 

The Proposed Development is located on Ardverikie Estate and Kinloch Laggan, approximately midway between Newtonmore and Spean Bridge, and would operate by transferring water between a lower reservoir, Lochan na h-Earba and an upper reservoir, Loch a' Bhealaich Leamhain. 

Further information can be found on Gilkes Energy Ltd website earbastorage.co.uk 

Planning was submitted for the Earba PSH in March 2024 - Section 36 planning application can be viewed on the Energy Consents website energyconsents.scot/ApplicationDetails.aspx?cr=ECU00005062 

The project is expected to start in mid 2028 and be completed in Late 2032. 

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 proposal and we want to understand what local people think about our plans.

We endeavour to take the time to discuss proposals with local community councils, encourage engagement from the wider community and listen to the feedback we receive.

We will do our best to answer any questions and address issues or concerns that are raised with us.

When our project progresses into construction, we will continue working closely with the local community to ensure that our work has as little impact on the lives of those living and working in the area and as many long term positive effects as possible.

How we’re embracing artificial intelligence (AI)
We intend to use AI to assist our experienced teams in the analysis of your feedback, so we can categorise key points raised more quickly. You can learn more about how we’re utilising AI on this dedicated web page.