Frequently Asked Questions

Pumped storage hydro (PSH) is a proven, low-carbon form of energy storage. It works by moving water between two reservoirs at different elevations, storing energy when demand for electricity is low and releasing it to generate electricity when the consumption of electricity peaks.

This technology enables renewable power to be stored when it is abundant, for later use when it is needed, helping to keep the lights on when the wind is not blowing or the sun is not shining without reverting to fossil fuel electricity generation.

Currently, the UK pays hundreds of millions in "curtailment payments" to electricity generators when supply outstrips the demand or consumption of electricity. Projects like Glen Earrach Energy (GEE) allow that excess energy to be stored and used, rather than wasted, therefore making better use of the clean power we already generate, cutting system costs, and reducing the reliance on fossil fuels.

By making better use of existing renewables and grid infrastructure, PSH reduces the need for further renewable development. Due to the size of the GEE project, if consented this scheme would deliver these meaningful benefits at scale. For example, GEE’s generating capacity could reduce the build out of onshore wind required for net zero in 2050 by about 300 6MW windmills. Similar benefits exist in relation to required grid build out.

GEE would be one of the UK’s largest and most efficient schemes of its kind, with up to 34GWh of clean energy storage. It is estimated to save the UK energy system around £3 billion in costs over its first 20 years, and is forecast to be carbon negative within 18 months of completion. By 2030, it could reduce the carbon intensity of the UK energy system by around 10%.

Without long-duration energy storage, the shift to renewables from fossil fuel generation cannot reach its full potential. GEE is designed to support that transition at scale, while bringing social and economic benefits to both communities and consumers.

If consent is granted, construction would begin from 2026, with first power delivered to the electricity grid in 2030 and completion by the end of 2031.

Peak construction (when the site will be at its busiest) is expected to last from the second half of 2027 until the first half of 2029.

Once operational, the scheme’s lifetime is expected to last for at least 125 years with regular maintenance and scheduled upgrades to key equipment required roughly every 25 to 40 years. Upgrades and maintenance will largely be on the electromechanical equipment, rather than requiring new construction, and this is not expected to cause any significant disturbance to communities.

The project has been designed to be as discreet as possible, and you can find more information on this point in the application documents (EIAR Chapter 6: Landscape and Visual, Volume 4: Visualisations, and Additional Information).

Stakeholders have raised questions around the visibility of the project once completed, particularly around the proposed works on Loch nam Breac Dearga and the Lower Control Works (where water will travel in and out of the scheme from Loch Ness).

Once operational, the majority of the project’s infrastructure will be located underground. The headpond (at the existing Loch nam Breac Dearga) will have three embankments built to expand the Loch’s capacity, accommodating the energy storage requirements of the project. These will not be visible from most viewpoints and will be landscaped as much as possible to blend into the environment, but we understand that this is a significant change. For visualisations of the headpond, please refer to the application documents (EIAR Volume 4: Visualisations).

The Lower Control Works will be located below the level of the A82 road on the shore of Loch Ness, and this will be carefully managed using natural materials to incorporate the structure into the landscape. The structure itself is designed to be low to the water, with no surface buildings in order to reduce any visual impact.

These elements have been carefully designed with community input to reduce visibility from popular viewpoints and walking routes.

Other than the Lower Control Works below the level of the A82, which has been designed to blend into the environment, there will be no structures on the shore of Loch Ness.

To see a rough indication of what the project will look like once complete, a 3D visualisation of the design can be found here:

We recognise traffic is one of the most sensitive local concerns, particularly on rural roads like the A831 and A82. Our planning from the outset has had a strong awareness of the A82 as a critical transport link for the local area, and we are also aware of the knock-on effect to other roads like the B862 on the south side of the loch, if the A82 is impacted.

We have amended our design to reduce the impact on the A82 as much as we are able to, including moving the construction of the Lower Control Works to a waterborne operation. We have also relocated the main access to the A831, whilst continuing to work to reduce overall vehicle requirements alongside carefully managed safety and traffic plans. This ensures that only main roads are used which are already designed for HGV traffic, rather than single-track roads, and avoids traffic turning off the A82 directly onto site access.

One of the figures quoted most often is a 670% increase in HGV movements on the A831 Strathnacro — equivalent to 178 vehicle movements (89 inward journeys and 89 outward journeys) per day. Importantly, this refers to an absolute worst-case scenario during the single busiest month of the construction period, where multiple major construction activities occur at the same time.

The statistics included in the application documents comply with planning requirements in that they offer an assessment of traffic levels during the busiest day of construction, and with conservative assumptions regarding transport loading. These figures therefore do not reflect the average traffic level over the entire construction phase. Instead, they represent the worst-case scenario in a confined period. This has been assessed taking a precautionary approach, however, as is explained below, we see significant opportunity to reduce these numbers and we are committed to make best endeavours to do so, in a transparent manner and in full collaboration with local communities.

The forecast average for the entire construction period is 54 HGV movements per day (27 vehicles arriving and departing), and outside of the busiest 12-month period this is reduced to approximately 38 HGV movements per day (19 vehicles arriving and departing), again assessed on a precautionary basis.

We are committed to further reducing transport and movement as much as possible, both to minimise local disruption and because this would benefit the construction process. As such, we will produce a Construction Traffic Management Plan (CTMP) in consultation with The Highland Council's Roads and Transport Planning team to ensure road safety and minimise disruption throughout the construction phase.

Our objective is for all rock, aggregate and sand for concrete production to be sourced from within the site, and significant design effort has been dedicated to make this possible. If this can be achieved (depending on the minerology of the rock on-site), the above traffic numbers can potentially be reduced to approximately 40% of the values presented, meaning an average of 11 HGVs per day over the full projection period, and 8 HGVs per day outside of the worst 12-month period.

Alongside this, we are working to develop additional measures which may result in a further reduction to traffic, including refining the project’s design to optimise the use of concrete and maximising the amount that vehicles can carry in one journey to lower the number of required movements.

We are committed to providing regular updates as our construction planning develops, and we are actively working to minimise the impact of traffic on the community. When we are able to confirm further traffic reductions, we will update the community as soon as possible.

Safety is our top priority, especially on rural roads where walking, cycling and agricultural traffic are common.

A Construction Traffic Management Plan (CTMP) will be developed in consultation with The Highland Council's Roads and Transport Planning team to ensure road safety and minimise disruption throughout the construction phase. Specific traffic management measures will be determined through this Plan, subject to planning conditions, to ensure appropriate mitigation measures are in place.

In addition, we understand that there has been concern around the intention to include signage on the access roads as the sole road safety impact mitigation. We want to clarify that we are committed to genuine mitigation of road safety concerns, and we will fully engage with local stakeholders to develop and implement effective safety measures, should consent be granted. We are keen to work with the local community to explore opportunities for the establishment of additional footpaths and similar physical measures to provide physical mitigation for increased traffic, particularly including exploring safety measures at the junction in Drumnadrochit and exploring how best to address school bus drop-off facilities to ensure safety of all school children.

The application documents (EIAR and Additional Information) are clear about the impact on peatland or blanket bog of different depths. For every hectare of impacted blanket bog, there is a corresponding commitment to restore degraded peatland well beyond the originally impacted area (NatureScot guidance for this is a 10:1 ratio).

This means there is a significant net benefit to the national peatland condition. These restoration measures will be subject to planning conditions and ongoing monitoring, making them formal and enforceable commitments. We stand fully behind these commitments and view this as an opportunity to deliver a measurable national net gain in peatland condition and carbon sequestration.

The application documents (EIAR) contain modelling for both construction noise and vibration impacts. We are committed to working within The Highland Council Environmental Health Officer’s recommended volume limits, with reduced volumes outside of core working hours.

Our assessment demonstrates that with mitigation measures in place, such limits can be achieved at the nearest residential receptors.

Where we have the option and ability to do so, we will schedule noise-generating works (including piling and blasting) at the Lower Control Works to be at times of the year and times of the day which will have minimal impact on local receptors, being aware of the tourism significance of Loch Ness. This will include avoiding noisy works early in the morning, late at night, or on Sundays. These restrictions will be controlled through planning conditions and managed via the Construction Environmental Management Plan (CEMP).

During operation, due to the underground location of the generators, turbines, and transformers (600m below the surface) we do not anticipate any significant noise or vibration to be produced by the scheme.

At peak construction (expected between late 2027 and mid-2029), up to 1,000 workers will be required on-site.

The vast majority of staff contributing to the project’s construction will be housed in accommodation on-site, to avoid impacting existing local housing and amenities, and importantly, to avoid creating additional traffic on nearby roads.

GEE's worker accommodation is designed to be self-contained, with medical, food and recreational services located within the site. This was a deliberate choice to reduce daily traffic numbers and to mitigate any additional stress on local services and amenities, whilst also benefitting workers housed on-site.

The workers’ accommodation and other compounds have also been relocated to the north side of the project site, away from existing population centres, to further avoid impacting the community as much as possible during construction.

GEE is committed to using local workers and businesses in the construction of the project where possible. We have already received several inquiries from both local people and businesses who are keen to play an active role in the construction and operation of the project. We will therefore hold local supply chain events closer to the time of construction, to allow additional people and businesses to get in touch and tell us where they can contribute.

GEE is one of the UK’s largest and most efficient pumped storage hydro projects. This means that the project is able to store more energy using less water than all other projects on Loch Ness combined. To find out why this is the possible, you can see a video explanation here:

At the very maximum output, with all units generating, the water level in Loch Ness would increase by under 3cm per hour. At the maximum pumping rate, the drawdown on Loch Ness would be around 2.6cm per hour. The forecast average change to the water levels due to the GEE scheme is expected to be around 16cm in any 24-hour period, with a maximum of 52cm on a few occasions throughout the year.

It is important to note that all water stored by the project will be returned to Loch Ness as part of the cycle. No new water will be added to Loch Ness, and no water will be permanently removed.

The GEE project has assessed strict operational parameters for Loch Ness water levels based on detailed modelling of water resources and flood risk receptors in both Loch Ness and the River Ness downstream.

Specifically:

• The "hands-off high level" (at which the project stops releasing water into Loch Ness) is set at 17.44 mAOD (metres Above Ordnance Datum); and

• The "hands-off low level" (at which the project stops pumping water from Loch Ness) is set at 15.42 mAOD.

We are aware of concerns around flood risk and are committed to working within the natural levels of Loch Ness, and to avoid any rapid change to the Loch’s water levels. This assessment means that when water levels in Loch Ness reach 17.44 mAOD, our operations would stop generating electricity and no further water would be released into Loch Ness.

This operational rule is specifically designed to prevent exacerbating high water levels during periods of heavy rainfall or snowmelt. This ensures the GEE scheme operates within the natural upper and lower limits of the Loch. The other schemes on Loch Ness (either existing or proposed) will also be working to a similar “hands off” set of levels so that water release during generation will not continue when loch levels are approaching the upper limit.

GEE has also committed to work with Scottish Canals on a modernisation of the Dochfour Weir. This is with an objective of conserving water during the summer, maintaining navigability and avoiding low levels in Loch Ness and the Caledonian Canal, improving fish passage over the weir, and restoring the River Ness to a natural flow which is de-coupled from any pumped storage activity. Importantly, we believe any such modernisation works need to be carried out without a permanent raise of the Dochfour Weir, so that the current flood carrying capacity of the structure is maintained. These works will be the subject of a separate planning application, with the GEE scheme conditional on the success of this separate application. With the right modifications, we believe this legacy structure will deliver benefits well beyond our project alone.

You can read in more detail about our approach to Loch Ness’ water levels in the application documents (EIAR Chapter 11: Flood Risk and Water Resources) and the Additional Information, which confirms that the “hands-off high level” is 17.44 mAOD rather than the 17.60 mAOD stated in the original EIAR. Details of the works planned on the Dochfour Weir are also included (EIAR Appendix 2.1 Dochfour Weir Upgrade Description, and EIAR Appendix 2.2, Letter from Scottish Canals).

A comprehensive assessment of the potential impacts on aquatic species was undertaken as part of the Environmental Impact Assessment of the project and reported in the application documents (EIAR) that accompany the application for Section 36 consent.

Chapter 9: Aquatic and Marine Ecology (and associated appendices) of the EIAR provides the specific detail and conclusions of this assessment. In addition, and for further ease of reference, Chapter 19: Summary of Effects and Conclusions of the EIAR provides an overview of all the project residual environmental effects following the implementation of the embedded and any additional mitigation measures as required. The project design also includes a smolt screen at the lower intake.

We are currently the only project to undertake a salmon smolt tracking study, the results of which will be used to inform our Fisheries Management Plan, including the potential curtailment of the plant operation during sensitive periods of smolt migration if required. For the construction period, mitigation measures are included in the Construction Environmental Management Plan and will be subject to The Highland Council, SEPA and NatureScot oversight. We are continuing to engage with consultees to take advice on this topic, and they have helped to scope the smolt study that is being undertaken.

Transmission infrastructure is the responsibility of SSEN Transmission and is considered through a separate regulatory and planning process.

We are not responsible for designing or delivering this infrastructure, and therefore cannot provide detail on what will be proposed. However, our scheme is designed to connect as efficiently as possible into the existing network.

Initial cabling on the site will be undergrounded to avoid visual impact, and the point at which we connect to the grid (Our GIS switchyard) has been located at the north of the site to encourage specific routing of the transmission line which minimises visual impact.

Our provisional assessment based on our best understanding of likely tower locations indicates that the towers will not be visible from Foyers, the majority of the A831 corridor, Drumnadrochit, and other surrounding communities. This will be confirmed by SSEN Transmission as they design the line in due course.

Please note that whilst we have undertaken all possible measures to reduce the impact and visibility of transmission infrastructure, and will continue to do so, final decisions will be made by SSEN Transmission as the electricity network operator.

We have undertaken an initial survey of private water supplies as part of the project's Environmental Impact Assessment, the results of which can be viewed within the application documents (EIAR Appendix 10.2).

Appendix 10.2 outlines potential mitigation, monitoring and a response plan. Further information on mitigation is outlined within Chapter 10: Water Environment and Appendix 10.4: Outline Water Management Plan. It is likely this will be secured via a planning condition.

We have since received the details of others concerned about the impact on their private water supplies, and we will contact those individuals in due course to ensure their water supply location is recorded as the project moves forward.

We kindly request that any further individuals concerned about private water supplies contact info@glenearrach.energy with the subject line "Private Water Supply" to make themselves known to the team and provide a name, address and phone number. We will then pass their details on to the appropriate team member to follow up.

Yes, a planning application was submitted for site investigation work, using seismic techniques to better understand the condition of the ground deep below the surface. However, the Highland Council recently confirmed that such works are considered as permitted development , and a formal planning application is generally not required for early works of this kind.

A separate planning application was submitted because we did not want to assume that this work fell under permitted development.

The proposed works would involve the use of small-scale squibs, with the aim of generating a vibration signal. The proposed charges are 25g (approximately the size of a shotgun shell) which will be buried in a hole beneath the surface and covered with sandbags to minimise any sound. No rock material would be moved, and this is not expected to produce any significant impact on local residents, given the detonation will be dampened and therefore will not produce an excessively loud noise.

We anticipate the works to commence towards the end of 2025 or later.

The visualisations provided as part of the application documents (EIAR) had been previously agreed upon with The Highland Council and NatureScot as a statutory consultee, to provide a range of representative viewpoints. Existing visualisations can be accessed in the EIAR Volume 4: Visualisations.

Further visualisations have also been included as Additional Information, at the request of consultees to assist their evaluation of the Section 36 application. This can be found within the Planning Application page of our website.

Unfortunately, we are not able to provide further visualisations beyond the above at this time.

From the outset, we have prioritised early and meaningful engagement, and local input has shaped this project from the start.

Engagement has been a priority from day one. Since the project was first announced, we have held:

• Four drop-in early engagement sessions in communities closest to the proposed works, before statutory requirements began. This helped us to refine the early design and implement improvements based on community feedback.

• Four statutory pre-application consultation events to gather additional feedback on the project design and outline further changes.

• Three further drop-in sessions following the project’s Section 36 application, to provide information on the planning process, and answer to questions about the Environmental Impact Assessment.

• A community quiz event, presenting a more relaxed format for questions to the project team.

• This is in addition to the helpful correspondence and feedback we have received directly, and our ongoing work with consultees and stakeholders to integrate the project with the community and environment.

We have also been engaging widely on the project’s Community Wealth Fund over the last year, bringing together three roundtable sessions with community leaders and experts, an array of one-to-one meetings with stakeholders, as well as a formal community benefit consultation in Spring 2025 which surveyed local opinion on the fund’s structure, governance, and focus areas.

All of this input has delivered significant design improvements, as well as shaping the Community Wealth Fund to be community-led from the very beginning.

To learn more about the process of engagement that has informed the Community Wealth Fund, please visit https://www.glenearrach.energy/community-wealth-fund

We are committed to an ongoing two-way dialogue and will continue to engage closely as both the project and the Community Wealth Fund move forward.

GEE’s project is set to deliver significant benefits to the communities surrounding the scheme as well as to the wider UK energy system. This includes reducing the need for further wind farm development, as well as providing around £3bn in savings for the energy system over the first 20 years by eliminating the need for curtailment payments, therefore contributing to lower energy bills for consumers.

Longer-term, the scheme will provide high-quality local employment for around 40 people during operation, and we are committed to using the local workforce wherever this is possible.

Alongside wider benefits to grid stability, carbon emissions and energy security, GEE has committed to providing 5% of gross margin revenues from the project to a Community Wealth Fund.

This commitment is expected to deliver around £20 million per year to communities surrounding the project. The GEE Community Wealth Fund is projected to be the largest of its kind in the UK energy sector, and we firmly believe that communities deserve a meaningful share in the value created by the project.

We have worked closely with local stakeholders to develop the Community Wealth Fund’s structure and governance, as well as gathering early ideas on what it could help address. This includes multiple roundtable sessions with community representatives and policy experts, a number of community drop-in sessions, as well as a formal survey of local views on how the fund should be delivered.

Over the course of our engagement, we heard the following priorities:

• The fund should be grounded in local knowledge, and decision-making must be community-driven

• It must be governed independently, with a long-term and flexible structure

• Its development should be transparent at every stage with clear rules, open processes and strong oversight

Some of the key focus areas for development shared by community members were:

• Jobs, skills, and business development

• Affordable housing and infrastructure

• Community wellbeing and local services

• Environmental restoration and access to nature

We are committed to ongoing dialogue to ensure the Fund is informed and directed by the communities closest to the scheme, and we look forward to continuing to work alongside local partners as it develops.

You can read more about our findings on Glen Earrach Energy’s Community Wealth Fund by visiting our website page here: https://www.glenearrach.energy/community-wealth-fund

Please see these included below. Further visualisations can be found in the EIAR Volume 4: Visualisations.