Battery Energy Storage Systems: planning guidance

4 BESS Planning & Design: Key Principles

Introduction

4.1 BESS projects can vary considerably in their scale, configuration, and geographic setting, and all applications will need to be carefully considered and balanced with regard to the specific context of each site, the nature of proposed development, and its compliance with the Development Plan as well as relevant material considerations.

4.2 Positive outcomes are best realised where applicants actively engage with key planning issues, through appropriate site selection, adopting the mitigation hierarchy through design development, early engagement with key stakeholders, and providing comprehensive application reporting that demonstrates policy compliance.

Appropriate Site Selection

4.3 The choice of location for BESS development, and specific site selection, can directly influence the range and complexity of planning issues to be addressed. Appropriate site selection is important for effective planning for BESS and ensuring that proposals align with national and local planning policy requirements.

4.4 With considered siting and design, BESS development may be appropriate in a wide range of locations across Scotland, and guidance cannot prescribe specific criteria for site selection. Applicants will wish to have close regard to policy principles and criteria set out in NPF4 including (but not limited to):

• Policy 1 on sustainable places which gives significant weight to the global climate and nature crises.
• Policy 2 on climate mitigation and adaptation which seeks to encourage, promote and facilitate development that minimises emissions and adapts to the current and future impacts of climate change.
• Policy 3 on biodiversity which seeks to protect biodiversity, reverse biodiversity loss, deliver positive effects from development and strengthen nature networks.
• Policy 4 on natural places which seeks to protect, restore and enhance natural assets making best use of nature-based solutions.
• Policy 5 on soils which seeks to protect carbon-rich soils, restore peatlands and minimise disturbance to soils from development.
• Policy 6 on forestry, woodland and trees which seeks to protect and expand forests woodland and trees.
• Policy 8 on greenbelts which seeks to encourage, promote and facilitate compact urban growth and use the land around our towns and cities sustainably.
• Policy 9 on brownfield, vacant and derelict land and empty buildings which seeks to encourage, promote and facilitate the reuse of brownfield vacant and derelict land and help reduce the need for greenfield development.
• Policy 11 on energy which seeks to encourage, promote and facilitate all forms of renewable energy development onshore and offshore, including energy storage (and outlines potential impacts to be addressed through project design and mitigation).
• Policy 14 on liveable places which seeks to encourage, promote and facilitate well designed development that makes successful places by taking a design-led approach and applying the Place Principle.
• Policy 20 on blue and green infrastructure which seeks to protect and enhance blue and green infrastructure and their networks.
• Policy 22 on flood risk and water management which seeks to strengthen resilience to flood risk by promoting avoidance as a first principle and reducing the vulnerability of existing and future development to flooding.
• Policy 23 on health and safety which seeks to protect people and places from environmental harm, mitigate risks arising from safety hazards and encourage, promote and facilitate development that improves health and wellbeing.

4.5 In instances where BESS development is proposed within designated and/or sensitive locations, applicants will wish to refer to relevant policy tests in NPF4 and to clearly demonstrate, where appropriate, the site selection process and to evidence specific locational need. Thereafter, it should be demonstrated how impacts have been avoided and minimised through the design process, and how mitigation and compensation measures are incorporated.

Landscape and Visual Effects

Characteristics of BESS development

4.6 BESS development typically comprises containerised battery modules, electrical infrastructure equipment, areas of hardstanding, ancillary buildings, security fencing, and lighting.

4.7 While typically low in height, battery units can result in an industrial development appearance and introduce regular and geometric building forms that may change the character of the site and surrounding landscape and affect views. Related electrical infrastructure or other development features (e.g. acoustic screening) may also be of greater height than the battery units themselves.

4.8 If not carefully sited, designed, and appropriately mitigated, the development and infrastructure associated with BESS can result in adverse impacts to visual amenity and landscape character. This is especially the case for larger scale development, and/or where situated in designated landscapes, scenic areas, and some rural settings, where sensitivity to change may be higher and potential for adverse effects more likely.

4.9 The visibility of development from homes, transport and walking / cycling routes, and other vantage points will be a consideration where applicable, with the potential to affect views and visual amenity from receptors around the site. This includes night-time visibility and impacts potentially arising from security lighting.

4.10 Consideration should be given to any cumulative landscape and visual effects of BESS development in combination with other development and infrastructure. Given the strong co-locational characteristics between BESS, substations, overhead lines, and other energy generating development, there can be potential for significant cumulative landscape and visual effects to arise in certain locations.

Effective Planning

4.11 In seeking to avoid, minimise, and mitigate landscape and visual effects, a design-led approach should be adopted that considers these issues from the outset of the planning process, including at site selection. As best practice, applicants are encouraged to identify and plan sites that inherently minimise visibility. This can include prioritising brownfield sites where feasible, avoiding sites in prominent or open and exposed areas, and seeking to site BESS development to benefit from natural screening and areas of lower landscape sensitivity.

4.12 Beyond site selection, applicants can seek to embed landscaping features to minimise and mitigate the potential visual impact and ensure proposals integrate with existing landscape taking account of NatureScot’s mapped landscape character types and their descriptions. Design should carefully consider the context of the site and its surroundings, its existing landscape features, and how this may change through proposed BESS development. While variable in the context of any specific site and proposal, landscape design may seek to include:

• Reinforcement or extension of existing landscape elements such as woodland, hedgerows, open moorland, or mixed grasslands. With consideration to the possibility and effect of any wildfires and ensuring growth is appropriately controlled.
• Incorporating native species planting characteristic of the surrounding landscape.
• Landscape boundary treatments such as woodland, hedgerow, and grassland belts to screen development.
• Open grassland, wildflower, or shrub planting to complement strategic landscape features.
• On larger sites, naturalistic bunds may be appropriate to screen development. Wherever possible using on-site soil materials and seeking to tie into existing contours, landform, and patterns, avoiding overly engineered forms that may themselves disrupt landscape or introduce new incongruous features.

4.13 Site layout and design measures can also be utilised to reduce landscape and visual effects and more closely integrate BESS development into existing surroundings. These may include:

• Minimising height and massing of BESS containers, ancillary structures and buildings as far as possible.
• Designing compact, efficient site layouts that minimise footprint (while remaining compliant with all relevant legislative requirements and standards), and orienting and configuring units to minimise visibility from sensitive receptors or viewpoints.
• Adopting natural colours / tones (dark greens / greys) and matte or muted finishes for surfaces that blend to existing landscape character. Avoiding the use of bright logos or other conspicuous signage and branding.
• Ensuring any lighting is LED, low-mounted, full cut-off lighting positioned inward / downward, with warm colour temperatures and other measures to minimise light pollution and night-time visibility (e.g. motion activated for remotely monitored sites).

4.14 In instances where development is of a large-scale, within or near a sensitive landscape, and/or there is potential for adverse effects to nearby landscape and visual receptors, it may be necessary to prepare a Landscape and Visual Impact Assessment (LVIA) as part of the application. The scope of a LVIA should be proportionate to the scale of the development and its sensitivity, but will typically include:

• Review, collation and mapping of baseline landscape and visual receptors, characteristics, value, and sensitivity.
• Zone of Theoretical Visibility analysis within an agreed study area.
• Selected viewpoint visualisations covering a range of views agreed with the relevant authority, with wirelines and photomontages prepared to show pre and post-development scenarios. It may also be appropriate to show time horizon scenarios (e.g. Year 1, Year 10) where planting is proposed, or night-time visualisations.
• Assessment of the nature and significance of effects to landscape and visual receptors, potentially including residential visual amenity assessments on any nearby properties depending on site location and proximity.
• Assessment of cumulative landscape and visual effects. See also section 4.7.

4.15 An LVIA should be prepared in accordance with the Landscape Institute’s Guidelines for Landscape and Visual Impact Assessment (GLVIA 3) to ensure a consistent best-practice approach.

4.16 Applied early in design development and developed with close regard to existing site context, these measures can ensure effects on landscape character, designated landscapes and visual amenity are avoided, minimised, and mitigated as far as possible.

Policy Context

• NPF4 Policy 4 on Natural Places
• NPF4 Policy 6 on Forestry, woodland and trees
• NPF4 Policy 11 on Energy

Ecology & Biodiversity Enhancement

Characteristics of BESS development

4.17 Like all development, BESS can impact on the natural environment and biodiversity through change in land use, vegetation clearance, and loss, disturbance, or fragmentation of habitats, however the type of impact and its significance will depend on the site location and surrounds.

4.18 More specific impacts arising from BESS development which may require careful consideration could include (but are not limited to):

• Disturbance to local wildlife such as birds and bats from continuous operational noise associated with cooling equipment and/or electrical infrastructure on the site.
• Potential effects on behaviour of nocturnal species from artificial lighting required for site security and operations.
• Risk of disturbance or damage to the natural environment in the event of a fire, including potential impacts to habitats and vegetation beyond the site boundary.
• Potential for pollution impacts to the surrounding environment from firewater or other emergency response activity, including nearby watercourses or other wetland and water-dependent habitats.

Effective Planning

4.19 NPF4 Policy 3 seeks to protect biodiversity, reverse biodiversity loss, deliver positive effects from development, and strengthen nature networks. Scottish Government Planning Guidance on Biodiversity sets out further detail on expectations for implementation of NPF4 policies which support the NPF4 outcome ‘improving biodiversity’, and appropriate tools and methods for assessing biodiversity. Policy 3 part b) applies to proposals for national or major development, or for development that requires an Environmental Impact Assessment.

4.20 NatureScot have also published Developing with Nature Guidance which provides guidance on securing positive effects for biodiversity from local development, as well as interim Guidance on the use of existing biodiversity metrics in the Scottish planning system. The full range of NatureScot’s standing advice and guidance that can assist applicants in planning to minimise impacts on nature and secure biodiversity enhancement is published on their website.

4.21 As set out within the Scottish Government Planning Guidance on Biodiversity, opportunities for safeguarding and enhancing biodiversity should be considered from the very earliest stages of development proposals, as a core part of the siting and design process, rather than being ‘bolted on’ at the end.

4.22 Effective planning and application of the mitigation hierarchy to avoid and minimise impacts to the natural environment, and enhance biodiversity, may include:

• Early completion of site ecological surveys where appropriate. The exact scope and nature of any survey will vary depending on the site, but would typically identify and map habitats and sensitivities to inform design development and provide the baseline from which appropriate mitigations and enhancement can be developed. As well as identifying habitats present this can consider potential for protected species (e.g. bats) and whether additional detailed survey may be required.
• Based upon thorough survey baseline, proposals should assess potential negative effects and seek to avoid and minimise these through careful consideration of siting, layout, and design of BESS and related infrastructures, prior to identifying enhancements.
• Integrating measures to enhance biodiversity that reflect and complement local ecological character. While variable in the context of any individual site, this could include native woodland planting, hedgerow boundaries, species-rich grassland, and integrating wetland habitats as part of SuDS and other blue and green infrastructures. Additional targeted measures to support habitat connectivity, nature networks, and specific species or ecosystems may also be appropriate.

4.23 Where development interacts with less common, or more valued, complex and extensive areas of biodiversity interest, expert ecological input is likely to be required.

4.24 Where the natural environment or biodiversity have potential to be impacted from fire and associated emergency response activity, it may be appropriate to provide additional information as part of an application. For example, some applicants have included information setting out how fire risk to wildlife will be avoided and/or mitigated (e.g. through fire breaks, fire-water containment systems) in a Battery Safety Management Statement (or equivalent) (see paragraphs 4.35 and 4.36). Pre-application consultation with NatureScot may be necessary where there is potential for impacts to protected areas.

Policy Context

• NPF4 Policy 3 on Biodiversity
• NPF4 Policy 4 on Natural places
• NPF4 Policy 6 on Forestry, woodland and trees
• NPF4 Policy 11 on Energy

Health & Safety

Characteristics of BESS development

4.25 When managed correctly, BESS can be operated safely and the likelihood of problems is low. However, the chemical nature of lithium-ion batteries used at many BESS sites can give rise to specific health and safety considerations. When faults do occur, these batteries can pose a significant fire risk due to thermal runaway. It is therefore essential that BESS are developed in line with appropriate health and safety standards and that regulations are adhered to. Careful consideration from the earliest stages of site selection and design can help meet these requirements.

4.26 The UK Government Department for Energy Security and Net Zero (DESNZ) has published Health and Safety Guidance for Grid Scale Electrical Energy Storage Systems (‘the DESNZ Guidance’). It provides detail on technical industry standards and best practice around the safe design, testing, installation, and operation of BESS technologies. While not exhaustive, developers in Scotland are encouraged to have regard to this guidance document as well as other applicable industry standards.

4.27 The DESNZ Guidance states “With lithium-based technologies, thermal runaway is a key failure mode which can lead to hazards to the nearby environment. Thermal runaway can be caused by a wide variety of internal and external factors, including physical damage, misuse, aging and fluctuating temperatures outside of the safe temperature range. Thermal runaway can lead to explosion and release of toxic gases or water run off.” The DESNZ guidance also points to opportunities to reduce overall system risk through the selection of appropriate equipment for hazard mitigation, such as BMS, fire alerting and fire suppression.

4.28 Although rare, fires at BESS developments are challenging to extinguish and can continue to burn from several hours to several days. If controlled or extinguished using water this can result in large volumes of contaminated fire-water runoff with further impacts on the surrounding environment.

4.29 The National Fire Chiefs Council (NFCC) have produced a BESS Position Statement as well as Grid scale energy storage system planning - Guidance for fire and rescue services - NFCC (‘the NFCC Guidance’). In publishing this guidance, NFCC seeks to support fire and rescue services to ensure they are aware of the location of all grid-scale BESS in their area.

Effective Planning

4.30 A site-specific approach should be adopted that is derived from the key principles and recommendations outlined, considering the specific nature of the site and proposed development and battery technology.

4.31 Features of development relevant to fire safety requirements (e.g. water storage, containment barriers, access points) should be included within the planning application and clearly marked.

4.32 Early consideration of the DESNZ Guidance and other wider industry standards is encouraged when designing BESS development. Applicants should ensure they are using the most up-to-date versions of all guidance documents at the time of their application. At the time of writing, areas of guidance and standards which may be of most direct relevance to site planning and design, relate (but may not be limited) to:

• Unit spacing and site layout
• Distances to boundaries and occupied buildings
• Site accesses and internal circulation
• Water supply in the event of a fire
• Firewater containment

4.33 In regard to site accesses and internal circulation, guidance on minimum dimensions for vehicle access routes is available from the Building Standards technical handbook 2025: Non-Domestic and SFRS can provide further advice if necessary. Applicants may wish to provide an appropriate vehicle tracking plan to demonstrate compliance.

4.34 In regard to spacing beyond the perimeter of the site, the NFCC guidance states “Distances between BESS cabinets/enclosures and occupied buildings will vary based on individual site designs. Proposed distances should take into account risks, including the impact of any vapour cloud. Any mitigation factors that have been incorporated into the site design should also be considered. An initial minimum distance of 30m is proposed between BESS cabinets (or associated infrastructure such as transformers and switchgear) and occupied buildings, before considering any mitigation such as blast walls. This distance is based upon the 100ft distance for remote installations cited in NFPA 855:2023”.

4.35 Specific consideration may also be required regarding potential for impacts to nearby watercourses and the wider water environment from any water used in the event of a fire. SEPA, jointly with the Northern Ireland Environment Agency, have published good practice guidance for Containing Major Spillages and Firewater at Industrial Sites – GPP18 including specific guidance on containment systems.

4.36 Some applicants have shared a Battery Safety Management Statement (or similar) explaining how relevant guidance and legislation has been taken into account and demonstrating how they have considered and embedded safety in their development proposal. These have included matters such as layout and design of BESS units, battery monitoring, incident detection, and notification processes; details of on-site drainage infrastructure and other environmental impact mitigation measures to control potentially contaminated run off in the event of a fire, and access arrangements to accommodate emergency and maintenance vehicles. Making information on these matters publicly available can help address concerns around health and safety and provide clarity on measures adopted to minimise risk to people and the environment. It is however an established principle that planning should not duplicate other regulatory regimes. (See also paragraphs 3.43-3.47).

4.37 SFRS are not a statutory consultee for planning applications. However, following submission of an application, Local Authorities/ECU may liaise with SFRS for advice and comment on an application if it appears the proposals do not meet the NFCC Guidance.

4.38 Applicants are encouraged to engage with SFRS at an early stage in the development of BESS proposals. To aid this process, any pre-application consultation sent to SFRS should detail how the proposed development has taken the NFCC Guidance and other relevant requirements into account. Where a development proposal does not align with relevant aspects of NFCC and/or DESNZ guidance, the decision maker will determine what weight to attach to this taking into account the circumstances of the case.

4.39 When considering the information required in respect of fire safety, decision-makers for planning and Section 36 consent applications for BESS will wish to note the established principle that these planning and consenting systems do not duplicate other regulatory regimes. Whilst it is not the role of the planning system to regulate fire risk, designers, installers and operators of BESS have a legal responsibility to comply with all relevant and applicable health and safety legislation which applies outwith the planning system. Section 5 contains information on other regulatory requirements.

Policy Context

• NPF4 Policy 11 on Energy
• NPF4 Policy 23 on Health and Safety

Noise and Vibration

Characteristics of BESS development

4.40 The operation of BESS generates noise from various systems and processes, in particular from cooling equipment, inverters, and transformers. Typical noise emissions from BESS include tonal hum (from transformers) and ‘whirring’ noise from fan blades or HVAC units, often with a more intermittent character depending on cooling requirements.

4.41 The noise emissions from individual BESS containers are typically limited, but large numbers of containers sited together and operating in tandem can result in a combined noise level with the potential to impact the amenity of nearby residents, communities, or other sensitive receptors.

4.42 Specific noise issues and impacts from BESS operation arise from the fact that:

• BESS development can be located in rural settings, where background noise levels are very low. As a result, even moderate noise generated from BESS operation may be perceptible and introduce a new noise source, with potential for impacts exceeding noise criteria defined through British Standards. In very quiet areas, this can present a challenge to achieving compliant noise outputs, even with incorporation of mitigation measures.
• BESS facilities operate 24/7 to meet charge / discharge requirements (albeit varying depending on use pattern), meaning that noise emissions are not limited to daytime hours and can lead to more sensitive night-time impacts.
• BESS facilities may be co-located with other energy generation development, energy infrastructure, or industrial development. Cumulative noise emissions and the gradual increase in ambient noise levels over time therefore need careful consideration.

4.43 There is typically less potential for impacts from vibration as BESS facilities do not have large moving parts during operation, however construction activities may result in short-term ground vibration impacts.

Effective Planning

4.44 Appropriate site selection is the most effective means of avoiding adverse noise impacts. Wherever possible, applicants are encouraged to develop on sites which are well-separated from sensitive receptors where potential for noise impacts is inherently avoided and minimised.

4.45 Beyond site selection, applicants can adopt a range of design, planning, and equipment specification measures to attenuate noise levels and potential for impacts from BESS. This may include:

• Layout and siting of equipment to minimise noise emissions. Noise emitting equipment can be located centrally within the site and/or where distance from nearby receptors is maximised, including appropriate separation distance from site boundaries. Noise-emitting equipment may also be oriented or sited to take into account any intervening structures, vegetation or contours in the land.
• Equipment selection and plant specification including low noise emitting models and technologies, and/or operational measures to avoid peak acoustic output during night-time hours. Confirmation of proposed equipment at planning application stage can enable more detailed and informed assessment of noise emissions, providing more certainty to stakeholders of potential impacts.
• Use of acoustic enclosures to dampen noise and contain noise-emitting equipment such as HVAC units.
• Creation of physical barriers to break direct pathways between noise emission and sensitive receptors. Where possible, this may prioritise natural screening such as woodland planting, bunds, or other features which contribute to wider landscape and biodiversity policy objectives. In certain circumstances, purpose-built acoustic screening (e.g. walls / fencing) may be appropriate to address a specific impact which cannot be otherwise avoided, though care should be taken around their design, visual impact, and implications for fire safety, emergency access, and surface water management / drainage.

4.46 A Noise Impact Assessment (NIA) may be appropriate on a number of sites. Applicants are encouraged to engage as early as possible in the planning process with Environmental Health Officers to agree on the methodology and approach to the NIA, and specific criteria to be applied to assessment. The NIA will typically include background noise measurements at nearby sensitive receptors, modelling and predictions of noise emissions from BESS equipment (including consideration of tonality and intermittency), and assessment against relevant criteria and guidance (including British Standards^[15], WHO Guidelines, Local Authority noise limits where relevant). Assessment is normally based upon the stated noise emissions of the selected plant / equipment operating at full capacity, unless an alternative approach is agreed with the Planning Authority based on the specific nature of the plant, site, or other factors.

4.47 It may be appropriate for a specific noise limit to be conditioned in order to provide a clear enforcement mechanism. Applicants may wish to engage early with local authorities to review wording of conditions and seek to agree appropriate noise limits. In circumstances where plant specification is yet to be finalised at the point of application, conditions may also be applied to require pre-commencement submission of final plant schedule and updated Noise Impact Assessment to demonstrate compliance with defined criteria.

4.48 Construction noise mitigation can be controlled through preparation of a Construction Environmental Management Plan (CEMP), with potential measures include limited hours, use of appropriate machinery with noise limiting equipment applied, and noise monitoring protocols. Specific measures can be detailed as part of a Construction Environmental Management Plan.

Policy Context

• NPF4 Policy 11 on Energy.
• NPF4 Policy 23 on Health and safety.

Land Use and Soils

Characteristics of BESS development

4.49 The development of BESS and associated infrastructure involves a change in land use at any site, with the potential for disturbance to soils and loss of productive or otherwise valuable land. Given the strong co-locational requirements between BESS development and electrical infrastructure, this means they might be proposed for development in rural and/or previously undeveloped sites, with higher potential for impacts to Prime Agricultural Land, or carbon-rich soils.

4.50 Where development takes place on peatland this can result in habitat loss and carbon emissions, potentially leading to significant environmental impacts. In the event of a fire within carbon -rich soils it can also be difficult to control and extinguish.

4.51 Applicants are encouraged to carefully consider soil and land classification and soil conditions from the earliest stages of development proposals, seeking to avoid and then minimise impacts through the siting and design process.

4.52 It is also important to consider the reversibility of the land-use change proposed by BESS development, after which the site could be restored to its former condition. Further detailed guidance on site de-commissioning and restoration is set out below.

Effective Planning

4.53 The classification of land and soils is an important consideration in the site selection process. Mapping of Prime Agricultural Land and Carbon-Rich and Peatland Soils^[16] can be used to inform constraints analysis, and developers should avoid locating development on protected and high-value soils wherever possible.

4.54 Where BESS development is proposed on peatland, carbon-rich soil, priority peatland habitat, or prime agricultural land, applicants should provide evidence of specific locational need and that there is no other suitable site (which may include robust evidence demonstrating consideration of alternatives).

4.55 In all cases, applications should demonstrate how the proposed development has been designed and will be constructed in accordance with the mitigation hierarchy by first avoiding and then minimising the amount of disturbance to soils on undeveloped land and in a manner that protects soil from damage. This will require an efficient approach to site planning with careful balance around scale of development and ensuring other mitigation measures such as bunds, SuDS, and any buffer zones to sensitive receptors are appropriately incorporated.

4.56 In instances where a BESS development site is proposed on peatland, carbon-rich soils or priority peatland habitat, applicants are encouraged to review NatureScot Guidance on Peatland, Carbon-Rich Soils and Priority Peatland Habitats, and engage with the Planning Authority / ECU and NatureScot.

4.57 NPF4 Policy 5(d) outlines that where development on peatland, carbon-rich soils, or priority peatland is proposed, a detailed site -specific assessment will be required to identify:

• the baseline depth, habitat condition, quality, and stability of carbon-rich soils;
• the likely effects of the development on peatland, including on soil disturbance; and
• the likely net effects of the development on climate emissions and loss of carbon.

4.58 The potential for construction phase impacts to soils such as compaction, erosion risk, and management of stockpiles are also important, and may be considered and addressed within a Construction Environmental Management Plan, and where necessary within a Peat Management Plan.

Policy Context

• NPF4 Policy 5 on Soils
• NPF4 Policy 11 on Energy

Water Environment

Characteristics of BESS development

4.59 BESS development involves sensitive electrical equipment, where even shallow flood depths could compromise safety, access, and operability. NPF4 policy 22 on flood risk and water management promotes avoidance as a first principle and aims to reduce the vulnerability of existing and future development to flooding. Policy 22 says that development proposals at risk of flooding or in a flood risk area will only be supported in limited circumstances, including for essential infrastructure where the location is required for operational reasons.

4.60 BESS development will typically include hardstanding for BESS units and infrastructures, vehicle access and turning, and other compound areas. This can increase surface water run-off with potential for impacts to local hydrology if not effectively managed and planned for.

4.61 In certain locations, development foundations and/or formation of hardstanding areas could have the potential to intercept or alter groundwater pathways, with implications for groundwater dependent terrestrial ecosystems or other groundwater habitats, including those which may be remote from the site.

4.62 In the unlikely event of a battery fire, large volumes of firewater run-off which may be contaminated with dissolved or suspended metals and chemicals could pose a pollution risk to soils, groundwaters, watercourses, and the wider environment if not effectively contained.

Effective Planning

4.63 SEPA’s Flood Risk Standing Advice for Planning Authorities covers essential infrastructure developments where there is no land raising or loss of floodplain capacity. Whether a location is required for operational reasons is a matter for the relevant Planning Authority to determine.

4.64 Applicants are encouraged to consider the water environment from the earliest stages of site selection and layout planning, having regard to waterbodies on or adjacent to the site, flood risk, drainage flows, groundwaters, wetlands, peat and carbon rich soils, and existing infrastructure.

4.65 Site layouts should incorporate SuDS and surface water management measures including attenuation ponds and tanks, appropriately sized to accommodate runoff in line with SuDS Manual (CIRIA C753) and not increase the risk of surface water flooding to others. Where necessary, runoff should be appropriately treated to prevent negative impacts on receiving water quality^[17].

4.66 In parallel, requirements for on-site water storage for use during firefighting should also be considered and reflected in site layouts, ensuring appropriate capacity with regard to NFCC guidance and wider industry standards as appropriate. If water is to be abstracted locally^[18] or diverted to fill holdings tanks, consideration should be given to how this might impact nearby water environment and habitats, including via hydrological links to another water source.

4.67 Firewater containment measures should be incorporated within the site area and embedded within the overall site drainage design as well as Emergency Response Plans prepared by the operator. Specific requirements will vary depending on the nature and scale of the site, but may include isolation tanks, bunded lagoons, isolation valve(s) and penstocks, interceptors and drainage cut-offs as necessary (or combinations thereof), to ensure that firewater is prevented from reaching surrounding water environments. SEPA have published specific guidance on containing major spillages and fire water at industrial sites which should be referred to, as well as NFCC guidance and the NFCC position statement.

4.68 As well as containment, regard should be given to how firewater would be treated and/or disposed of safely, to avoid discharge to the water environment.

4.69 A Flood Risk Assessment and Drainage Strategy may be required for proposals in areas at risk of flooding, to demonstrate how water environment issues have been considered in design and appropriate mitigation measures incorporated into the development.

4.70 For details of when to consult SEPA on planning proposals for BESS please consult their Development Management Consultations Thresholds and Standing Advice guidance. The standing advice includes information on drainage. Further SEPA guidance on drainage and discharge of surface water for BESS projects is contained in their SEPA’s BESS webpages.

4.71 Construction stage impacts to the water environment also require careful consideration, and a CEMP and Pollution Prevention Plan demonstrating how pollution pathways are prevented may be required. SEPA advise that any discharge of water run-off from a construction site to the water environment must be authorised by SEPA and advice on best practice guidance and regulatory requirements is provided on SEPA’s website.

Policy Context

• NPF4 Policy 11 on Energy.
• NPF4 Policy 20 on Blue and green infrastructure
• NPF4 Policy 22 on Flood risk and water management.

Cumulative Effects

Characteristics of BESS development

4.72 BESS projects are often situated in the same area as other energy projects, clustering around existing or planned grid infrastructure and renewable energy generation sites. Incremental delivery of this development can, over time, alter local character or amenity through combined effects and require careful consideration.

4.73 There may be circumstances where the impacts of BESS in isolation are not significant and/or require a certain degree of mitigation, but when considered in combination with other existing and planned development are more significant and require further careful consideration.

Effective Planning

4.74 NPF4 Policy 11(e) requires that project design and mitigation will demonstrate how cumulative impacts are addressed. The NPF4 glossary defines cumulative impacts as the impact in combination with other development. That includes existing developments as appropriate, those which have permission, and valid applications which have not been determined. The weight attached to undetermined applications should reflect their position in the application process.

4.75 Both EIA^[19] and non-EIA development should consider cumulative effects as part of the application process. Applicants are encouraged to clearly demonstrate how this has been taken into account as part of the site baseline and informing development design.

4.76 A range of topic areas are relevant in the consideration of cumulative effects. Depending on the nature of the site and its environment, the scale of the development, as well as other development in the vicinity (existing or planned) consideration should be given to whether there are likely to be cumulative effects, including during construction and operation. These could include (but are not limited to):

• Landscape and visual impacts – considering combined visibility of proposed development and showing viewpoints with other development. NatureScot have published guidance on assessing cumulative impacts for onshore wind energy development which may provide a useful reference.
• Noise environment –combined noise levels with other existing or proposed development in the vicinity and considering incremental change in background noise levels.
• Ecology and biodiversity – assessing combined effects on local ecology and habitat connectivity and how this informs the approach to biodiversity enhancement measures, including how enhancements can be optimised across multiple developments.

4.77 As best-practice in the earliest stages of design development, applicants should identify and review existing and planned development in the vicinity and consider potential cumulative impacts. This can inform design development and the approach to mitigation of impacts, ensuring that potential for combined effects is assessed, modelled, and mitigated appropriately. Early discussion with the Local Planning Authority and/or ECU can help facilitate this.

4.78 It is important for applicants to consider that different projects within a shared locality may be brought forward by various applicants under separate consenting regimes^[20] with different decision-makers. Applicants should identify and consider all relevant projects, irrespective of consenting regime. Applicants are also encouraged to define the parameters for inclusion of cumulative projects with regard to the scale and nature of their project and seeking to ensure that all combined effects ‘pathways’ to receptors are considered (across all development types).

4.79 Effective planning for cumulative effects could, as best practice, involve coordination between projects to align mitigation measures and ensure these are complementary. For example, this could include collaboration around appropriate measures to support biodiversity and habitat connectivity networks, or coordination of traffic management and road infrastructure to reduce impacts to local transport network.

4.80 In areas where multiple energy generation and infrastructure projects are coming forward, effective pre-application community consultation is critical. Through pre-application activity, applicants are encouraged to proactively demonstrate how they have identified and considered the cumulative impact of planned development, and what measures are proposed to minimise and mitigate impacts. Applicants are also encouraged to explain the importance and reasoning for clustering between projects and why this is necessary.

Policy Context

• NPF4 Policy 3 on Biodiversity
• NPF4 Policy 4 Natural Places
• NPF4 Policy 11 on Energy

Site De-Commissioning and Aftercare

Characteristics of BESS development

4.81 BESS projects typically have an operational lifespan following which the energy storage equipment and plant may cease operation and require decommissioning (or renewal and upgrading). Prior to final de-commissioning there may also be replacement, repair, or servicing of plant and equipment during the lifespan of development.

4.82 BESS development includes specialist equipment, including battery technologies with chemical elements which are potentially harmful if they degrade or are damaged. It is important that decommissioning provides for safe removal, and recycling or disposal of batteries, as well as related development infrastructures to ensure that land is not left in derelict condition and/or environmentally damaged following development. The waste hierarchy should be applied to waste produced during construction, operation and decommissioning of the development.

4.83 Due to particular considerations around decommissioning, operators may wish to engage with SFRS where decommissioning activities are to be undertaken.

Effective Planning

4.84 As far as possible, applicants are encouraged to design BESS with eventual decommissioning and restoration processes in mind. This will be supported where there is a clear understanding of existing soil and ground conditions, avoiding areas of contamination, ensuring containment processes are incorporated, limiting extents of hardstanding or complex foundations, and using materials and components suitable for disassembly and recycling.

4.85 By actively incorporating future decommissioning and restoration into site design and planning, safer and more sustainable solutions can be provided that account for the full lifecycle of the development. Applicants are encouraged to state the anticipated lifecycle of the development as part of applications and demonstrate how site decommissioning and restoration has been considered and will be undertaken.

4.86 It is recognised that at the point of the planning application, full details of the decommissioning and restoration may not be known, or only high-level information may be available. It may be appropriate to describe the key steps and activity to be undertaken, and overall principles of decommissioning and restoration, but not the specific processes.

4.87 Therefore, in many instances a planning condition to secure submission of a detailed Site Decommissioning, Restoration, and Aftercare Plan (or similar) will be required. This may include requirements for submission of a plan prior to commencement of development, outlining proposals for decommissioning and removal of development plant and infrastructure, restoration and aftercare measures including environmental management provisions.

4.88 It is good practice for a Site Decommissioning, Restoration, and Aftercare Plan to define clear restoration outcomes and objectives. Where the site is agricultural or greenfield in nature, decommissioning and restoration should, as best practice, generally seek to restore the site to its original condition, or deliver environmental enhancements. This may include restoration to a specific soil standard, habitat type, or works to meet other environmental and ecological objectives.

4.89 Conditions may also require that the plan is reviewed and further detailed prior to the point of final site closure and decommissioning, to ensure contemporary best-practice is adopted, any relevant regulatory or legislative changes are considered, as well as any other changes in site character, surroundings or environmental context that may arise over the lifetime of development. In many circumstances it will be appropriate for a final plan to be submitted and agreed in advance of final cessation of site activity, and this may include consultation with SEPA.

4.90 As best practice, plans may also include consideration of safe battery recycling or disposal, albeit this is regulated separately through The Waste Batteries and Accumulators Regulations 2009.

4.91 It is important that the commitment to safe decommissioning and restoration of the site is retained, irrespective of any change in development owner or operator. To ensure this is robustly enforced, it will in many cases be appropriate for a bond or financial guarantee to be secured. This ensures that the costs of decommissioning and restoration can be met in the event that the site ceases operation and the applicant / operator fails to uphold their commitment and implementation of the measures within the Site Decommissioning and Restoration Plan.

4.92 Applicants and local authorities / ECU are encouraged to be pro-active in considering how a bond and financial guarantee will be secured for site decommissioning and restoration^[21]. Either planning conditions or planning obligations can be used to secure financial guarantees, and it will remain in the judgement of the decision-maker as to the most appropriate mechanism in the context of an individual proposal and applications.

4.93 Conditions and/or legal agreements to secure Site Decommissioning and Restoration Plans and related financial guarantees can also provide assurance to communities and other stakeholders that strong safeguards are in place to avoid derelict or hazardous site conditions.

Policy Context

• NPF4 Policy 5 on Soils
• NPF4 Policy 11 on Energy