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  • Knocknagael - Tomatin

    Following a reappraisal of project requirements, an upgrade to the existing Beauly to Knocknagael 132kV double circuit overhead line is no longer required. Therefore, the project name has been changed from Beauly-Knocknagael-Tomatin to Knocknagael-Tomatin to avoid unnecessary confusion.
  • Knocknagael-Tomatin project

    Type: Transmission and connections

    Current status: In development

    Location: Inverness-shire,  Scotland

    Pre Application Notice consultation events 

    Scottish Hydro Electric Transmission plc (SHE Transmission) has now submitted
    the Proposal of Application Notice (PAN) to The Highland Council under the terms
    of the Town and Country Planning (Development Management
    Procedure)(Scotland) Regulations 2008. This notice states our intent to submit a
    planning application to The Highland Council to construct and operate a new
    275/132kV substation near Tomatin at National Grid Reference (NGR): 275458

    SHE Transmission has a statutory obligation under its licensed conditions to
    provide connections to all customers who make applications via the National Grid.
    The below grid connections are contracted to connect at the proposed Tomatin
    • Glen Kyllachy transmission grid connection
    • Allt Duine transmission grid connection
    • Tom nan Clach transmission grid connection

    SHE Transmission is holding PAN public consultations as follows:
    Tuesday 28 July 2pm – 7pm Strathdearn Hall, Tomatin
    Wednesday 29 July 2pm – 7pm Strathnairn Hall, Daviot
    The consultations will comprise of display boards, and members of the project team
    will be present to answer questions. To comment on the proposals, either come
    along to the event or contact our Communications Manager:
    Write: Jenna Black (Corporate Affairs)
    Inveralmond House, 200 Dunkeld Road, Perth, PH1 3AQ
    Tel: 01738 455155/ 07876 837490
    More information and comment forms can also be found on the dedicated website:

    Public consultations

    We hosted three events in march 2015 to allow members of the public to comment on our proposals. The events comprised of display boards and members of the project team were available to answer questions and receive  comments. 
    Farr event
    The events were followed by an 8 week consultation which ended on Friday 15 May. We are currently analysing the results and will publish an update once this is complete.

    Project background

    Additional wind generation to the south of Inverness has triggered the need to reinforce our existing electricity transmission network in the area. The Knocknagael-Tomatin Reinforcement is the proposed solution to enable the additional wind farm generation to be connected into our network.
    Map of area

    Project Description


    The proposed project now comprises of the following elements:

    • Knocknagael to Tomatin - - Construct approximately 24km of 275kV double circuit overhead line between Knocknagael substation and the proposed Tomatin substation on a new alignment.
    • Knocknagael to Farr – – Dismantle the existing 132kV overhead line between the Knocknagael substation and the Farr substation
    • Tomatin Substation – Construct a new 275/132kV Substation near Tomatin, adjacent to the existing  Beauly to Boat of Garten 132kV double circuit overhead line.
    • Knocknagael Substation – existing 132kV overhead line from Beauly into Knocknagael via a new sealing end compound (where overhead lines terminate onto underground cables), and connect the proposed Knocknagael to Tomatin 275kV overhead line via a new sealing end compound

    Knocknagael to Tomatin 275kV overhead line

    The approach in identifying and assessing possible corridors capable of accommodating the proposed new overhead line was consistent with our internal guidance on the routing of steel lattice towers.

    The guidance refers to the application of the “Holford Rules” to inform overhead line routeing. These rules advocate the application of a hierarchical approach to routeing which first avoids major areas of high amenity, and which then considers factors such as backdrop, woodland and orientation.

    Using this guidance, four overhead line route corridors were identified to four potential substation locations, as presented in the map below.
    map of area
    Corridor A emerged as having least adverse interaction with the key environmental features and sensitivities considered in this study. Further engineering and environmental assessment identified a potential overhead line route alignment within Corridor A which is identified by the pink overhead line corridor presented in the map below.
    In December 2013, we published a consultation document to seek feedback regarding the route of the new 275kV Knocknagael to Tomatin overhead line and the location of the preferred Tomatin substation at site 1. Public consultation events were held in January 2014 as part of the consultation exercise. Further public consultations were undertaken in April 2014.

    We reviewed the consultation feedback which resulted in a number of changes to the alignment, as shown by the blue overhead line corridor.

    Tomatin 275/132kV substation site selection

    The approach to the site selection process for the Tomatin 275/132kV substation took account of technical, economic and environmental factors in selecting the preferred sites.

    Three existing substations (Knocknagael, Boat of Garten and Farr) and four potential new substation sites were considered as potential options to be assessed based on existing and future circuits that require to connect to the substation, including wind farm developments. These locations are identified in the map below.
    Map of area
    Using our internal substation site selection guidelines, the three existing substation sites at Knocknagael, Farr and Boat of Garten were ruled out alongside Site 2 and 3.

    Further detailed site assessment saw Site 1 become the preferred site option.

    In December 2013, we published a consultation document to seek feedback regarding the route of the new 275kV Knocknagael to Tomatin overhead line and the location of the preferred Tomatin substation at site 1. Public consultation events were held in January 2014 as part of the consultation exercise.
    Further public consultations were undertaken in April 2014.

    Feedback from this consultation highlighted concerns from the local community in regards to Site 1.

    Following this consultation, we reassessed the substation site options and new sites were identified by the project team, landowner and members of the public. 

    The new options were not originally considered due to the high altitude of these sites. Sites at altitude greater than 400 metres require a different type of technology, namely GIS (Gas Insulated Switchgear), due to the extreme weather conditions that could potentially be experienced at these sites. The previous sites identified (sites 1 and 4) were situated at an altitude slightly lower than 400m.

    The map below presents the new site options.
    Map six
    The selection of the preferred site for the substation at Tomatin has been undertaken as a combination of the operational/technical, economic and environmental assessment scores for each site using our Substation Site Selection Guidelines.

    Based on the information obtained through detailed technical assessments and from ongoing consultation we have determined that on balance site 5 is the preferred substation option and shall be taken forward for detailed design and Town & County consent application.

    To access the proposed substation two access options are being considered as presented in the map below.
    Map seven

    About us

    We are the transmission licence holder in the north of Scotland and have a duty under Section 9 of the Electricity Act 1989 to facilitate competition in the generation and supply of electricity. We have obligations to offer non-discriminatory terms for connection to the transmission system, both for new generation and for new sources of electricity demand.

    Our approach

    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. 
    If 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.

  • Write to:

    Lesley Dow
    Inveralmond House, 200 Dunkeld Road,

    Perth PH1 3AQ.

  • Open for business

    Our Open for Business (O4B) initiative gives local firms the opportunity to register their business services for a potential share in our investment in projects across the Highlands and Islands.
    Image link to the Open for business web page. Will open in a new window.
  • Knocknagael - Tomatin public exhibitions - January 2014

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