stronelairg wind farm 132 kv grid connection · pdf filestronelairg wind farm 132 kv grid...

Stronelairg Wind Farm 132 kV Grid Connection

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Who We Are Scottish and Southern Energy Power Distribution is part of the SSE plc group of companies. We own, maintain and invest in the electricity networks in the north of Scotland – the electricity transmission network (132 kV and above) and the electricity distribution network (below 132 kV). In Scotland, Scottish and Southern Energy Power Distribution is made up of two businesses: Scottish Hydro Electric Transmission (SHE Transmission) owns and

maintains the electricity transmission network across the north of Scotland, in some of the UK’s most challenging terrain; and

Scottish Hydro Electric Power Distribution (SHEPD) operates the high and low voltage electricity network that distributes electricity to around 700,000 customers in north mainland Scotland and the Scottish islands.

Keeping the Lights On and Supporting Growth SHE Transmission owns around 5,000km of electricity transmission infrastructure which spans about 70% of the land mass of Scotland. Electricity networks like this provide a physical link between electricity generators and electricity users. We have three main objectives over the next decade: To keep the lights on for our customers across the north of Scotland; To invest for a greener future; and To minimise, as far as possible, our impact on the environment. As we are the only company that owns an electricity transmission network in the north of Scotland we are closely regulated by the energy regulator Ofgem. We are issued with a licence to operate and we must adhere to the terms of the licence. For this reason we are operated on a very separate basis to other SSE businesses. Our licence stipulates that we must develop and maintain an efficient, coordinated and economical system of electricity transmission. Our responsibilities also extend to ensuring that there is sufficient network capacity and a connection for developers who wish to export their generated electricity to the national grid. If a generator applies to connect to our network, we are required to facilitate this under the terms of our licence.

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.


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Project Background

We are the licenced owner of the electricity transmission network in the north of Scotland. Operating under licence means that we have certain obligations that we must fulfil. These obligations include maintaining the existing network to ensure that the lights stay on and investing in the network to provide the infrastructure needed to allow generation developments to connect to it. The transmission network gathers energy from power stations, hydro-electric generation schemes and wind farms and carries it to areas where it is to be used. We work with the Transmission System Operator, National Grid, who is responsible for operating the transmission network across the whole of Great Britain, to make sure that power flows smoothly and reliably across our network. A request has been made to National Grid by the developer of Stronelairg wind farm to provide a grid connection to connect the wind farm. As the wind farm is in our licence area, we are responsible for providing the infrastructure needed to connect the wind farm. Stronelairg wind farm received consent from Scottish Ministers in June 2014. This consent is currently the subject of a judicial review. However, we must progress with proposals for the grid connection to ensure that we meet the proposed grid connection date. The grid connection will comprise a new 132 kV overhead line or underground cable together with a new substation. We are undertaking a route options appraisal and substation site selection exercise to identify a technically efficient and economic route and location for the grid connection, taking into account environmental factors to minimise any potential adverse impacts on the environment. We are here today seeking views from local residents about our proposals.

Stronelairg Wind Farm: Location Plan

Stronelairg Wind Farm Key Facts and Information

Number of Turbines 67

Consented June 2014

Estimated Connection Date

March 2017


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Project Description

The aim of the project is to provide a grid connection for Stronelairg wind farm to the transmission network. The proposed grid connection would comprise a new connection from the Stronelairg wind farm on-site substation, to a new 132 / 400 kV substation located adjacent, or with-in close proximity to, the existing transmission network. A new overhead line OR underground cable would be required to complete the connection between the substations. We are currently at an early stage of the project and are undertaking a number of studies to identify the most appropriate solution and location / route.

Proposed Project Timeline


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Substation Site Selection (Strategic)

We need to identify a suitable site to accommodate a new substation. In order to do this we have undertaken a strategic review of potential locations, utilising the existing transmission network within the general vicinity of Stronelairg wind farm. Potential options for the proposed substation are shown in the table and figure below. Following standard criteria detailed within our Site Selection Guidelines, an appraisal of these strategic options has been undertaken to assess the potential positive and negative aspects of each possible location. This process eliminated unsuitable sites on the grounds of cost, engineering, and environmental considerations. The Melgarve area is considered the most suitable for the proposed substation due to proximity to the wind farm, capacity of the existing transmission network and potential to avoid significant environmental effects. A detailed site selection process is being undertaken in this area to identify a suitable site.

Substation Option Comments Taken forward for further consideration

Fort Augustus Over 20 km from wind farm site Substation site currently at capacity Significant technical and environmental challenges with grid connection

route due to topography and proximity to settlement

No

Foyers Over 25 km from wind farm site

No opportunities to extend substation site due to physical constraints

Grid connection would require routeing through challenging terrain Potential for grid connection route to impact upon properties and

settlements

No

Other options along the Beauly to Denny overhead line

Options to the west, south west or south east of the wind farm considered but discounted due to extremely challenging topography

Potential for impact upon designated sites, such as the Cairngorms National Park and the Monadhliath SAC / SSSI

No

Melgarve Shortest and most direct route from wind farm to transmission network Sparsely populated area with good access from the local road network Grid connection would require routeing through challenging terrain

Yes

Plan Showing Strategic Sites Considered


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Substation Site Selection (Detailed)

Following identification of the Melgarve area as a potential area for a new substation site, we are undertaking a detailed site selection exercise to identify the most suitable site to accommodate a new substation. The new substation site should be located as close to the existing transmission network as possible to minimise further connection requirements to the network. Substations should be located on relatively flat ground with good ground conditions (avoiding areas of deep peat). Areas where opportunities exist to visually screen the substation site are preferred in order to minimise potential landscape and visual impacts, and other environmental impacts should be minimised where possible. Environmental designations within the vicinity of the study area include the Cairngorms National Park, the Monadhliath Special Area of Conservation (SAC) / Site of Special Scientific Interest (SSSI), the River Spey SAC / SSSI and the Corrieyairack Pass Scheduled Ancient Monument. Potential impacts on these designated sites, as well as other environmental considerations, should be minimised as far as practicable. Potential site options are being investigated throughout the study area. Initial indications suggest that a substation site within the area marked as Option B on the plan below could be feasible from a technical and environmental perspective. Throughout the life of our projects, we aim to work positively with the local community, stakeholders and interested parties. We welcome comments on our proposals in order to ensure that local issues are taken into account when designing projects.

Substation Site Selection Plan

Substation - Consenting Process

Consent for construction of the new substation would likely be sought by way of a planning application to The Highland Council under the Town and Country Planning (Scotland) Act 1997. Due to the size of the substation being in excess of 2 hectares, the development falls within the category of ‘Major Development’ under the Town and Country Planning (Hierarchy of Development) (Scotland) Regulations 2009 (The Hierarchy Regulations). The site will be the subject of a rigorous environmental appraisal to assess potential impacts on factors such as ecology and ornithology; soils and hydrology; cultural heritage; habitat and flora; and landscape character and visual amenity. The appraisal would evaluate potential environmental impacts of the preferred substation site and provide appropriate measures to mitigate against such impacts as appropriate.


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Substation Design Options

Gas Insulated Switchgear (GIS)

Air Insulated Switchgear (AIS)

The new substation would either comprise Air Insulated Switchgear (AIS), or Gas Insulated Switchgear (GIS). Within an AIS, the live electrical equipment uses air as the insulating medium. This results in a larger footprint due to the clearance distances required between electrical equipment. Within a GIS, live electrical equipment uses a special gas as the insulating medium, usually SF6 gas. Live electrical equipment is enclosed in a building, rather than exposed, and the use of the gas reduces the clearance distances required between electrical equipment. This results in a smaller footprint for a GIS compared to an AIS. The figures below provide a comparison of these two options.


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Grid Connection - Overhead or Underground? In combination with the substation site selection process, we are undertaking a detailed assessment to identify potential grid connection routes and options. The grid connection route from the wind farm on-site substation to the new substation site will be approximately 8 km in length. A key consideration for this grid connection will be whether to proceed with an overhead (steel lattice tower) connection, or an underground cable connection. Both options have a number of factors to consider, such as constructability, environmental impact and maintenance requirements. As part of our consultation process we are seeking to engage with members of the public, the local planning authority and other key stakeholders to discuss these issues before arriving at a preferred solution.

Grid Connection - Route Selection As part of the route options appraisal, a number of corridors have been identified which are potentially suitable for either an underground cable or overhead line connection. The approach we are taking in identifying and assessing possible corridors capable of accommodating a new grid connection is consistent with national guidance on the routeing of steel lattice towers (if an overhead option were taken forward). The guidance recommends a hierarchical approach to routeing which avoids major areas of highest amenity first, then avoids smaller areas of high amenity, and which then considers factors such as backdrop, woodland and orientation. Other factors such as topography, peat depth and habitat type are also considered. Using this approach, four main grid connection corridors have been identified, as shown in the figure below. These options will be subject to more detailed technical and environmental surveys in order to identify a preferred route.

Grid Connection - Consenting Process

An overhead line would require consent under Section 37 of the Electricity Act 1989 and would be subject to determination by The Scottish Ministers. Permission to install an underground cable would be subject to discussion by The Highland Council. Either option would be the subject of a rigorous environmental appraisal which would assess impacts on ecology and ornithology; soils and hydrology; cultural heritage; habitat and flora; and landscape character and visual amenity. The appraisal would evaluate potential environmental impacts of the preferred grid connection route and provide appropriate measures to mitigate against such impacts as appropriate. We will continue to work with environmental consultants and grid connection engineers to identify a technically feasible and economically viable route which gives rise to: The least disruption to the amenity of people living and working in the area; The least impact on the physical and natural environment, and on nationally important species, habitats and cultural assets; and The least disruption to current land use and management practices.


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How do I have my say?

We are keen to receive feedback from the local community and other interested parties on our proposal. Please also take the time at the event to speak to members of our project team, who are here to answer any questions you may have and explain the information presented on the boards. Comments can be submitted as follows:

At the exhibition today – complete a Comments Form and place it in the box provided.

By post – complete a Comments Form and post it to our Liaison Manager (details below).

By email – complete a Comments Form and email it to our Liaison Manager (details below).

Comments forms and all the information from today’s event will also be available to download from the project website at www.ssepd.co.uk/melgarve Information can also be posted out to you by our Liaison Manager upon request. Please make your comments as specific as possible in order to help us consider them in relation to our proposal. The closing date for comments for this exhibition is Friday 7th November 2014. Contact details for the Project Liaison Manager are as follows: Neil Anderson

SHE Transmission

Inveralmond House, 200 Dunkeld Road, Perth, PH1 3AQ

Email: [email protected]

Mobile: 07500 912 506

Photographs of Melgarve Area

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