Greens (New Deer 2) 400kV Substation

SSEN Transmission operates, maintains, and improves the high voltage electricity transmission network in the north of Scotland.

Our network extends over a quarter of the UK’s land mass and some of its most challenging terrain. This area has a lot of renewable energy potential such as wind, solar, hydro and marine power.

We work with the National Grid Electricity Systems Operator so that electricity generated in the Highlands and Islands can reach homes and businesses across Britain.

SSEN Transmission is owned 75% by SSE plc and 25% by Ontario Teachers’ Pension Plan.

We are closely regulated by the independent energy regulator, Ofgem, for the work we do constructing, operating, and maintaining the transmission network in the north of Scotland.

The costs of constructing, operating, and maintaining the transmission network are shared between all those using the transmission system, including generation developers and electricity consumers.

Ofgem set how much money we invest, what return we make on this investment and how these costs are recovered from users of the electricity transmission system.

What is Pathway to 2030?

Pathway to 2030 is a series of projects to increase capacity of the transmission network in northern Scotland. It is part of a national effort to upgrade power lines across Great Britain to connect and transport renewable electricity, especially from offshore wind farms.

These projects contribute towards meeting climate goals and renewable targets, ensuring energy security and supporting Scottish and UK Government targets for a just transition to a net zero future.

Why is it needed?

1. Addressing Climate Change: The UK and Scottish Government have ambitious targets to combat climate change and guarantee a secure and reliable supply of energy. The UK is aiming for 50 gigawatts (GW)* of offshore wind-generated electricity by 2030. Our Pathway to 2030 projects have been identified as required to help achieve such targets by delivering the vital infrastructure required. *For background, A GW is a unit of measurement of electrical power. It is equal to one billion watts.
2. Promoting Energy Independence: In 2022, the UK Government set out a strategy to reduce dependence on volatile global gas markets, moving to local, sustainable electricity sources instead. Establishing the necessary infrastructure for this is critical.
3. Planning for future need: Experts with the National Grid Electricity System Operator carry out extensive analysis and research to predict the UK’s future energy needs. This information is then carefully considered to guide infrastructure upgrade decisions.
4. Approved by Ofgem: Britain's independent energy regulator, Ofgem, granted approval for these projects in December 2022 as part of its strategy for accelerated network upgrades.

More information explaining the need for these projects, the Government policies that underpin this need and how the need has been identified and assessed can be found here.

Yes, even though the Pathway to 2030 projects will help meet the UK Government's target of carrying 50GW of offshore wind energy by 2030, the UK Government has also pledged to fully decarbonise the electricity system by 2035. To achieve that target, further infrastructure will be required. The Electricity System Operator, National Grid ESO, is expected to outline these further network infrastructure requirements in early 2024.

SSEN Transmission is responsible for where and how the high voltage transmission network operates in the north of Scotland. However, we don't determine where energy is generated – nor where it is needed.

We have a legal obligation to provide electricity generators access to our network, so that the electricity they generate can be transported across the GB to meet the energy demand of homes and businesses.

The north of Scotland is rich in renewable energy, especially wind, water, and marine sources meaning this region is vital for the UK and Scotland's climate goals. Our area covers a quarter of the UK landmass and will be crucial in the move towards a low carbon future.

Our approach to optioneering (routes for overhead lines or sites for substations) is underpinned by our statutory obligations, as set out in the Electricity Act Schedule 9, to ‘develop and maintain an efficient, coordinated and economical electricity transmission system’. Having regard to the “desirability of preserving the natural beauty, of conserving flora, fauna and geological and physiographical features of special interest and protecting sites, buildings and objects of architectural, historic or archaeological interest; and do what we reasonably can to mitigate any effect which the proposals would have on the natural beauty of the countryside or on any such flora, fauna, features, sites buildings or objects’.

As a result, our optioneering process seeks to balance technical and cost considerations with environmental considerations. To select a proposed option which is economically viable, technically feasible, minimises impacts on important resources or features of the environment and reduces disturbance to those living in it, working in it, visiting it or using it for recreational purposes. The option must also be capable of being granted consent by either the Scottish Government (in the case of overhead line projects) or local planning authorities (in the case of substation projects).

To do this we consider specific topic areas within the environmental, technical and cost categories and assess each in terms of the potential for the option to be constrained. We allocate a Red/Amber/Green (RAG) rating to each topic to highlight where potential issues may be present and use this to help compare the different options. The appraisal seeks to compare the wider implications of each option on those topics (both individually and combined) and reach a reasoned conclusion, on balance across all topics, as to the ‘preferred option’ to take forward.

Any weighting of certain criteria as being of more importance than other criteria would depend on project specific considerations. For example, if a particular technical or environmental constraint has been identified as a priority consideration through stakeholder engagement (or engineering specification) and is unable to be overcome, this will inevitably carry greater weight in the comparison of options which may otherwise contain constraint that can be easily designed out or mitigated.

We follow this comparative approach through stages of refinement. For overhead lines this starts with wider corridors and progress to assessment of routes and alignments. For substations, we start with a long list of sites, which is refined through further assessment to identify one site. Consultation with stakeholders is essential throughout this process so that their views can be taken account of in our considerations prior to progressing to the next stage.

The culmination of this process identifies a ‘proposed option’ that will be taken forward to detailed design, environmental assessment and consent applications.

Consultations began at an early stage of project development, long before any decisions on power line routes or substation locations were made.

Tower locations were not shown because this information is not yet known. Early feedback is crucial, so potential route options were discussed with key stakeholders.

Our goal at this initial stage is to select routes approximately 1km wide that minimise physical or environmental obstacles and disturbances, while also being practical and cost-effective. We presented these routes to the public, statutory and non-statutory organisations to explain our current assessment and thoughts and listen to feedback.

Stakeholder feedback guides our projects from the start. All feedback is considered, and where possible and feasible, adjustments can be made, in which case we will ensure any changes are presented at future consultation events.

Feedback importance: SSEN Transmission values feedback from stakeholders and local communities and considers it throughout the project development process.

Whist community feedback is not our only consideration, we wish to develop all projects sensitively and to reduce impacts on communities as much as possible. Community feedback provides an essential insight into local issues that helps to refine the design, routes, and substation locations.

What we can do: Following consideration of all feedback, we consider what opportunities there are to modify our project's design, route, and substation locations.

What we can't do: We don't decide on the overall need for the Pathway to 2030 projects; that's National Grid ESO’s and Ofgem's role. Therefore, we can't consult on the core necessity of these 2030 plans. Find out more here. 

In November 2020, SSE became the first company to produce a Just Transition Strategy, introducing 20 key principles to ensure fairness as we move away from carbon-heavy activities and embrace climate-friendly changes.

The Pathway to 2030 projects align with these principles, promoting job opportunities, local suppliers, and preserving cultural heritage. Early in project development, SSEN Transmission made sure to engage with communities for feedback and insight.

To read more about our principals click here.

SSEN Transmission will publish the Report on Consultations in November 2023 which detail decisions made on the Pathway to 2030 projects and our response to feedback from the consultations earlier in the year.

The next formal consultation for the public on these projects is currently scheduled for February/March 2024, where details on overhead line alignments and substation locations will be shared for further feedback.

A final round of public consultation is expected to follow later in 2024 in advance of submitting planning applications to the relevant planning authorities. It is important that any views stakeholders have in relation to the project are also formally submitted as part of the statutory consenting process, to ensure that they are appropriately considered by the determining authority.

Environmental Impact Assessment Reports (EIARs) for the Pathway to 2030 projects will be prepared for the chosen options, in line with the relevant legislation.

Once completed, the EIARs will be accessible online via our project website, the Scottish Government’s Energy Consents Unit applications portal, and relevant Local Authority planning portals (depending on the consent being applied for).

Hard copies will also be available to view locally and these will be advertised at the time.

We prioritise environmental protection in our infrastructure projects, strictly adhering to environmental policies and regulations.

We follow a mitigation hierarchy strategy of “avoid, minimise, mitigate and restore” to safeguard local, national and international designated environmentally protected areas.  

We also acknowledge that minimising impacts is not enough on its own, and we have therefore committed to delivering a Biodiversity Net Gain (BNG) on all our projects; as well as compensatory planting for any trees felled during the construction phase, where possible with native species. Where our projects are unable to completely avoid irreplaceable habitats (for example peatland or ancient woodland), we have also introduced a commitment to restore more habitat than we affect.

During our assessments, comprehensive surveys identify potentially affected wildlife, guiding mitigation efforts. For example, bird surveys are ongoing, with winter surveys planned for 2023/24.

We also assess habitats and other species along our routes. Our consultation process to date has highlighted sensitive areas, and we continue to work with environmental experts and seek community feedback to refine our approach.

When planning our overhead line and substation projects, we thoroughly consider environmental, cultural, and built heritage factors in potential locations.

We make use of national archives and data sources as well as gathering data from Local Authorities and detailed site surveys to identify and assess the potential impact on archaeological sites, listed buildings, and other heritage assets.

Environmental Impact Assessment Reports (EIARs) detail these findings and recommend ways to lessen any potential adverse effects. We've received feedback about sensitive archaeological and cultural sites from a range of stakeholders, including local heritage and archaeological groups, all of which our environmental experts have considered.

When planning routes for overhead lines and substations, we consider visual impacts and how this may affect the local scenery, visitor experience and communities.

For each project we develop, we conduct a Landscape and Visual Impact Assessment. This is one element of the Environmental Impact Assessment Reports that forms part of our application to the local authorities and Scottish Government. In this assessment, we consider visual impact from centres of population, popular spots, like walking paths and tourist sites, and where possible reduce any potential negative visual impacts.

When developing overhead lines and substations, we focus on having a minimal noise impact. Detailed noise assessments are conducted as part of our Environmental Impact Assessment, and include current noise levels, potential new noise as a result of our infrastructure, and mitigation measures where required, to ensure noise is within acceptable levels.

In our early project development, we consider flood risks and drainage. We aim to avoid areas prone to flooding and conduct assessments when necessary.

Our team includes a variety of water and flooding experts who help design systems to manage water flow around our sites. Before construction, we will have a plan in place to protect both surface and groundwater and reduce potential impacts.

We have consulted on a Community Benefit Fund for projects until 2026, a first for a transmission operator in Scotland. This fund lets us work directly with local communities to support initiatives in northern Scotland.

We want to give back to the communities hosting our transmission network and to help fund projects that can leave a lasting, positive legacy in those areas.

We're encouraging the UK Government and Ofgem to recognise the crucial role the north of Scotland plays in energy targets in any upcoming guidance, ensuring that community benefits will reflect this significance.

Additionally, our projects will boost the economy, supporting local jobs and businesses. Recent studies show our Pathway to 2030 programme could contribute over £6bn to the UK's economy, support 20,000 jobs across the UK, and benefit Scotland by around £2.5bn, supporting 9,000 jobs.

We value engaging with local communities and residents to gather feedback on our plans. While our projects can cause some uncertainty, we aim to be transparent and start these discussions early. We always welcome and encourage suggestions on improving our approach and work collaboratively with communities as our projects evolve.

The UK Government, following advice from Public Health England, has set guidelines on safe levels of exposure to electric and magnetic fields (EMFs).

These guidelines, adopted in 2004, are based on international standards by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). These guidelines are designed to set conservative exposure levels for the general public to electric and magnetic fields and they are endorsed by the UK’s health protection agency Public Health England, the World Health Organisation and the UK Government.

The electricity industry abides by these rules, ensuring that all new equipment is safe according to official guidelines. A Code of Practice, published jointly in 2012 by industry and the then Department for Energy and Climate Change (now part of the Department for Energy Security and Net Zero), sets out all the practical details needed to apply the exposure limits for transmission lines. The electricity industry designs all new equipment to comply with the Government guidelines as set out in the Code of Practice. This includes measures such as adhering to statutory ground clearance requirements and ensuring optimum phasing of high voltage double circuit overhead lines.

Further information on EMFs can be found on ENA’s website.

We understand our projects may impact land and property. Compensation for any impact is determined by law, specifically the Electricity Act 1989 and the Land and Compensation Act 1973.

Each compensation case will be reviewed individually based on these laws. We aim to limit the impacts and welcome feedback to help in this effort.

We aim to work cooperatively with stakeholders, including landowners, during the development of the projects.

While we might need to acquire land for substations or rights for overhead lines, our preference is to reach voluntary agreements. Using statutory powers is an absolute last resort.

If we do use them, we'll ensure fair compensation based on established industry standards.

A Notice of Intended Entry is a formal notice given to landowners and occupiers, based on the Electricity Act 1989.

It grants us and our contractors the right to enter land after 14 days to conduct surveys related to our project, including environmental assessments, engineering walkovers, and drone surveys.

It's essential to note that these letters are not linked to compulsory land purchase. If there are any concerns, recipients can contact us using the information provided in the letter.

We're looking at using steel lattice towers, averaging 57m in height, for our upcoming Pathway to 2030 400kV overhead line projects.

This is similar to our operational Beauly-Denny line, where 80% of its 600-plus towers are below 57m, ranging from 42m to 65m in height.

The cost of improving the electricity network is covered by GB electricity consumers. It's essential to balance this cost with environmental, technical, and societal factors.

We conduct a Cost Benefit Analysis for our projects, but the cheapest options aren't always chosen. Factors like minimising environmental impact or ensuring technical viability also play an important part in this.

SSEN Transmission's return on investment is determined by Ofgem's regulations, no matter the technology used.

In its assessment of what is required to meet 2030 targets, National Grid ESO concluded there is a need for onshore and offshore projects.

Overhead lines can carry roughly three times more power than subsea cables, making them more efficient and cost effective for energy bill payers.

Technical challenges and constraints limit the use of only offshore solutions. Moreover, onshore reinforcements help support local electricity needs and improve the network’s reliability across northern Scotland.

Where a line exists, it doesn’t necessarily mean that it would be appropriate to build a new one next to it, there are many considerations as to why this may not be possible.

Sometimes, there is no space for new infrastructure due to existing constraints, including proximity to homes. However, in some areas, it is possible to place new lines near the old ones.

These aspects are considered in the optioneering phases of our projects for which we also seek stakeholder views.

The environmental, technical, and operational constraints associated with undergrounding at extra high voltages, particularly 400kV, make the option extremely challenging to deliver in many areas of Scotland.

Some of the challenges that contribute to this position:

1. Technical Limitations: No underground cables for these high voltages (275kV or 400kV) currently exist in our area. Underground cables need specific ground conditions and present challenges in maintenance and power restoration, especially if faults occur.
2. Environmental Impact: Undergrounding can have lasting environmental effects, for example impacts on habitats and hydrology, and the area required for laying cables needs to be clear from significant constructions or vegetation for easy access during construction and repairs.
3. Terrain Concerns: The region's terrain often has slopes that are difficult to install and finding a suitable route for underground cables without challenges is extremely difficult.
4. Infrastructure Needs: For underground cables longer than 1-2km, additional substation infrastructure would be needed, enlarging the project's footprint.
5. Operational needs: Restoring power in the event of a cable fault can take significantly longer than for an overhead line. Faults on overhead electricity lines can typically take a few hours to a few days to repair and are generally easy to locate. Underground cable faults often require extensive works, specialist resource, tools and equipment to locate the fault, followed by significant civils work to expose the damage, replace the damaged section and then it can take up to a month to carry out the repairs. This presents significant risks to security of supply and network reliability. It also impacts on our ability to meet our licence obligations of maintaining an efficient transmission network.
6. Cost: Underground cables at 400kV are estimated to be between 5 and 10 times more expensive than overhead lines, and since these costs are reflected in consumer bills, it's a factor that needs to be considered.

Even if technically feasible, undergrounding over a significant length of or the entirety of a project would be unreasonable as it would be contrary to our licence obligations to be economic and efficient in respect of additional costs to the end consumer and also have additional risk to the electricity transmission network in the event of cable failure and consequent outages.

Given these constraints and our responsibility for an economical and efficient transmission network, overhead lines are our main choice for the onshore ASTI projects. Where there is a clear evidence base to justify undergrounding, this will be carefully considered.

For more detailed information on the undergrounding of cables, click here.

The choice between underground cables and overhead lines is based on the technology used and the power requirements:

1. Technology Type: The Western Isles connection uses High Voltage Direct Current (HVDC) technology, suitable for connecting the Western Isles' power generation. This HVDC technology has low electrical losses and provides better control over the island's network conditions. It requires only two cables for a 1.8GW rating.
2. Power Requirements: The Pathway to 2030 projects, including routes like Spittal-Beauly, requires a 400kV onshore overhead line to transport much more power, 5GW. This setup permits the connection of much more generation. Achieving this rating with HVDC would necessitate at least three subsea cables.
3. Feasibility: Using underground cables for such high ratings isn't viable technically, economically, or environmentally due to the sheer number of cables needed.

While underground cables work for the Western Isles connection, they aren't practical for the larger Pathway to 2030 projects.

While the T-Pylon has been developed for use in England and Wales, it is not currently deemed suitable for our projects in the north of Scotland for several reasons:

1. Weather Impact Our region experiences more severe weather conditions, with increased impact from wind and ice. Using T-Pylons would mean shorter spans between structures, resulting in more structures, thus increasing the visual impact, land occupation, and construction traffic.
2. Material Lifespan: The composite material used for T-Pylon's diamond insulators might only last about 20 years. In contrast, the glass insulators on our lattice steel towers have a life expectancy of 40-50 years.
3. Transport & Delivery: The T-Pylon's large steel sections need a large number of low-loaders for delivery, significantly affecting local traffic. Their design could also force new lines to be closer to major roads, impacting our ability to route away from properties. Lattice steel towers are more compact for transport, minimising traffic disturbance.
4. Design Flexibility: T-Pylons can only turn up to 30° angles, while our lattice steel towers can turn up to 90°. This flexibility helps us avoid communities, viewpoints, and environmentally crucial sites. The limited direction change of T-Pylons would hinder our ability to minimise line impact.
5. Reliability & Repair: T-Pylons support an entire circuit on a single diamond so in the unlikely event of a failure the entire circuit could be lost, whereas lattice steel pylons use a double circuit. Repairs would take significantly longer, delaying power restoration.

Given these factors, we've determined that T-Pylons aren't currently suitable for our projects, as they might result in greater community and environmental impact and increased construction traffic.

We're aware of the impacts from new projects and we are committed to minimising them through thorough environmental assessments.

Our focus includes mitigating effects on biodiversity, water, soil, and traffic disturbances. A Construction Environment Management Plan will be set up, using existing routes to lessen disruptions.

During construction, expected short-term issues may include noise and traffic disruptions. Before starting, we'll have a plan to manage these, including organising deliveries and travel to avoid busy times and sensitive areas.

We'll work closely with community groups and contractors to ensure adherence to mitigation measures. Typically, most project components will take around four years to complete.

All project documents, which include maps of the suggested routes for the overhead lines can be found on our project pages. Contact details of your local Community Liaison Manager are also available.