National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Site visit made on 30 January 2023 by Ben Plenty BSc (Hons) DipTP MRTPI an Inspector appointed by the Secretary of State Decision date: 13th March 2023 Appeal Ref: APP/N5090/W/22/3298962 National Grid Mill Hill Substation, Land west of National Grid Mill Hill Substation, Mill Hill NW7 1NT • The appeal is made under section 78 of the Town and Country Planning Act 1990 against a refusal to grant planning permission. • The appeal is made by HB333MIL Limited against the decision of London Borough of Barnet. • The application Ref 20/4241/FUL, dated 9 September 2020, was refused by notice dated 7 April 2022. • The development proposed is the installation of a battery storage facility including inverter and transformer stations, battery storage containers, other associated infrastructure works, security fencing and lighting. Decision 1.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision The appeal is allowed and planning permission is granted for the installation of a battery storage facility including inverter and transformer stations, battery storage containers, other associated infrastructure works, security fencing and lighting at National Grid Mill Hill Substation, Land west of National Grid Mill Hill Substation, Mill Hill NW7 1NT in accordance with the terms of the application, Ref 20/4241/FUL, dated 9 September 2020, and the plans submitted with it, subject to the conditions within the attached schedule. Preliminary Matters 2. The proposed Battery Storage Facility (BSF) would include a site area of 0.49ha. The facility would include a welfare/storage container and control room that together would have a gross internal area of 51sqm. Remaining elements of the proposal, being plant and machinery, would not be deemed as ‘buildings’. Consequently, whilst interested parties have asserted that the proposal would be over 1,000 sqms, it would not meet the definition of a ‘major’ development by virtue of Part 1, paragraph 2 of the Town and Country Planning (Development Management Procedure) (England) Order 2015. Main Issues 3. The appeal site is within the metropolitan Green Belt.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Section 13 of the National Planning Policy Framework (the Framework) establishes the national policy objective to protect the Green Belt. Paragraphs 149 and 150 define different types of development that would not be inappropriate development in the Green Belt. It is uncontested by main parties that the proposed BSF would not comply with any such provisions. I see no reason, within the evidence, to disagree with this assertion. The proposal would therefore be deemed to be inappropriate development in the Green Belt. https://www.gov.uk/planning-inspectorate

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Section 13 of the National Planning Policy Framework (the Framework) establishes the national policy objective to protect the Green Belt. Paragraphs 149 and 150 define different types of development that would not be inappropriate development in the Green Belt. It is uncontested by main parties that the proposed BSF would not comply with any such provisions. I see no reason, within the evidence, to disagree with this assertion. The proposal would therefore be deemed to be inappropriate development in the Green Belt. https://www.gov.uk/planning-inspectorate

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Appeal Decision APP/N5090/W/22/3298962 4. Paragraph 147 and 148 of the Framework state that inappropriate development in the Green Belt is, by definition, harmful and carries substantial weight. Such development should not be approved except in very special circumstances. It continues that very special circumstances will only exist if the harm to the Green Belt by its inappropriateness, and any other harm, would be clearly outweighed by other considerations. 5. Accordingly, in consideration of the evidence, the main issues are: • the effect of the proposal on the openness of, and purposes of including land within, the Green Belt; and • Whether any harm caused by the proposal, by virtue of being inappropriate development in the Green Belt, and any other identified harm, would be clearly outweighed by other considerations to result in ‘Very Special Circumstances’. Reasons Green Belt - openness and purposes 6. The Development Plan for the district includes the London Plan 2021, the Barnet Core Strategy 2012 (CS) and the Barnet Development Management Policies 2012 (DP). Policy G2 of the London Plan seeks to resist inappropriate development in the Green Belt except in very special circumstances.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision CS policy CS7 seeks to protect the Green Belt and DP policy DM15 requires Green Belt development to comply with the Framework. Policy DM15 seeks to resist inappropriate development and to refuse development in the Green Belt, that is not compatible with its purposes and objectives and would not maintain its openness, except in very special circumstances. These objectives are consistent with the Framework and therefore these policies carry full weight. 7. The fundamental aim of the Green Belt is to prevent urban sprawl and keep land permanently open1. Openness has both visual and spatial qualities. The site consists of part of a field. This is largely enclosed by tree and hedge boundaries, including some woodland areas, especially to the north and east of the field. The site is within the lower part of the field within gently sloping land with higher land to the east. The landform, and extent of field boundary screening, would reduce the overall visual effect of the proposal from most wider views. 8. The proposed BSF would consist of twenty containers housing battery storage systems, ten inverter/transformer stations and other supporting equipment.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision It would be enclosed by a weldmesh fence and partially by a retaining wall. The units would vary in heights, the highest being around 3.7 metres high. The compound itself would be cut into the landscape, meaning that the west corner would be around two metres below the adjacent natural land level. Furthermore, the compound would be enclosed by a landscape buffer consisting of native hedging. 9. The field is currently grassland and used for equestrian grazing in association with the use of the neighbouring fields. I undertook my visit at a time in the year when the leaves of deciduous trees had fallen, meaning that my observations were made when natural screening was at its least favourable. 1 Paragraph 137 of the National Planning Policy Framework https://www.gov.uk/planning-inspectorate 2

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Appeal Decision APP/N5090/W/22/3298962 This has aided my understanding of the wider visual effects of the proposal throughout the year, and I have noted that leaf cover was still relatively dense around the appeal site in winter months. Furthermore, only the west boundary of the site would be exposed to views from the retained part of the field. The field, and its neighbouring fields, are also used by walkers. However, I am cognisant that the land is privately owned by the Appellant, and there are no public rights of way through the site or the adjacent fields. 10. The nearest public vantage points, into the fields, are from the gated access from Partingdale Lane, parts of the Burtonhole Lane Bridlepath and Hillview Road. Views of the fields can also be obtained from the rear aspects of nearby residential properties, especially those of Burtonhole Close and Hillview Road. Nevertheless, views of the appeal site itself would be restricted by the adjacent woodlands and tree groups, screening the proposed development and resulting in limited intervisibility to public or private views. 11. The proposed containers, inverters and other equipment would be relatively modest in size and widely distributed throughout the compound.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision These would be comparatively low-lying, and the facility would be enclosed by a relatively dense existing and proposed landscape screening. Consequently, whilst including a comparatively large area of land the proposal would result in only a negligible adverse visual impact on the surrounding area, due to topography and screening. 12. In spatial terms, the proposal would include a number of industrial features that would cumulatively erode the undeveloped nature of the existing site. However, these elements would maintain space between them and would be relatively small-scale within the wider context. The BSF is proposed for a temporary 40-year period. This represents a considerable period of time over which the effects would be experienced. Nonetheless, the impact on the Green Belt would not be permanent, limiting its long-term effects. Consequently, taking both visual and spatial impacts of the proposal together the scheme would result in a moderately harmful impact on the openness of the Green Belt. 13. Paragraph 138 of the Framework defines the five key purposes of the Green Belt.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision These are to check unrestricted sprawl of large built-up areas, prevent neighbouring towns merging, safeguard the countryside from encroachment, preserve the setting of historic towns and assist in urban regeneration (by encouraging the reuse of urban land). Despite the comments of the Council, I am unconvinced that the proposal would contribute towards urban sprawl or towns merging as the site is set away from the nearest built-up area. In terms of encroachment, the proposed scheme would place a range of industrial plant within a fenced compound. These would enclose the existing open green space with development that would result in encroachment, in contradiction of a Green Belt purpose. 14. The proposal is around 600 metres from Mill Hill Conservation Area and is some distance from the closest identified listed buildings. Due to intervening screening, the significance of these heritage assets would be preserved. As a result, historic towns would be unaffected by the proposal. The proposal would not contribute to the reuse of urban land. However, the proposal is intrinsically linked to the existing substation and the Appellant has demonstrated that it is unable to be located on previously developed land.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision https://www.gov.uk/planning-inspectorate 3

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision https://www.gov.uk/planning-inspectorate 3 Appeal Decision APP/N5090/W/22/3298962 15. The proposal, as inappropriate development, would by definition harm the Green Belt. It would result in encroachment and moderate harm to the openness of the Green Belt. All harm to the Green Belt carries substantial weight. Other Matters 16. The proposed development has generated substantial concern from the local community resulting in the submission of around 946 objections. A common issue relates to the benefits of the valley to walkers who use the area for recreation use resulting in health and wellbeing benefits. However, the appeal site and its surrounding fields are in private ownership and no public rights of way pass through the fields to the west of the site. Public routes that pass through the area consist of Partington Lane and the bridleway of Burtonhole Lane to the east of the substation where views to the appeal site would be limited or fully screened. Therefore, whilst the site may be partially visible from some distant private views, it is largely hidden from public views. As a result, the effect on the health and wellbeing of local walkers would be minor and insubstantial. Wildlife effects 17.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision The site is within the ‘Mill Hill Substation Pastures’ Site of Interest in Nature Conservation (SINC). The SINC includes a relatively large area that takes in fields to the east, west and south of the existing substation. The Appellant’s Ecological Assessment2 identifies statutory designated sites within 5kms of the site. It is recognised that interested parties state that Totteridge Fields Nature Reserve is closer than stated and that Darlands Nature Reserve has been omitted. However, I am satisfied that the Assessment has adequately identified these features in tables 3.1 and 3.2. I also recognise that whilst the Assessment finds that no aquatic habitat is within 250 metres of the site, interested parties find Folly Brook is 150 metres away. However, based on the evidence before me I find that it would be highly unlikely that aquatic wildlife would be affected by the proposed development and no concern was raised on this matter by the Council’s ecologist. 18. Paragraph 174 of the Framework requires that planning policies and decisions should contribute to and enhance the local environment in a number of ways, including the provision of a net gain for biodiversity.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision The Assessment states that the site would include 0.39 hectares of the SINC and describes the site as being semi-improved grassland. Although interested parties suggest that the site would be larger than that stated and result in a loss of more of the SINC, I am unconvinced and find the Council’s and Appellant’s evidence in this regard suitably robust to understand the area affected by the proposal. I have determined appeal on basis of what is before me. 19. The Assessment identifies that no species of birds would be likely to nest within the site due to its limited ecological value and the local availability of more suitable habitat in the wider area. It found that no trees within the site had the potential to accommodate roosting bats although trees within the wider area had some potential for bat roosts. No badger setts were found on site and due to the absence of aquatic habitat in or around the site no amphibians were recorded. Overall, the site was found to have limited ecological value and the 2 Ecological Assessment, by avian ecology, dated 8/9/20 https://www.gov.uk/planning-inspectorate 4

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Appeal Decision APP/N5090/W/22/3298962 proposed development was not expected to affect local wildlife, a conclusion that I find to be robust based on the surveys undertaken. Furthermore, whilst the existing site is used for horse grazing, which may incidentally create some ecological habitat value, such creation of biodiversity would be minor. 20. The Assessment recommends mitigation for the partial loss of the SINC through the provision of hedgerow planting creating new habitat areas, bird and bat boxes and other habitat improvements. The proposed landscape design plan3 identifies enhanced habitat creation through a combination of native species scrub planting and grassland enhancement. These measures would be appropriate mitigation for the loss of the existing grassland area. 21. Trees within two groups on site would be felled to facilitate development. These have been found to offer limited understory growth and are of low ecological value. Whilst the loss of green infrastructure is regretful, this would be offset by replacement landscaping within land set aside for new habitat creation on the perimeter of the site. I therefore have no objection to the limited tree loss proposed.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Also, the perimeter trees proposed to be retained could be adequately protected during construction by tree protection measures. 22. The Council’s ecologist was satisfied that the reduction of SINC could be adequately offset by the delivery of the proposed mitigation. Accordingly, taking these points together, the proposal would not materially harm the SINC subject to the proposed mitigation that can be adequately secured by condition. 23. Accordingly, although the proposal would result in the reduction of the size of the SINC this would not result in a net loss of biodiversity. There is no single or mandatory approach to calculating biodiversity net gains that might arise from implementing a planning permission. The proposed improved local habitat would result in a biodiversity net gain of at least 10%, using the Natural England metric, as evidenced in the biodiversity assessment4. Consequently, the proposal would not result in a net loss of biodiversity. Noise effects 24. Paragraph 185(a) of the Framework requires development to be appropriate for its location taking into account its likely effects on existing living conditions.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision This requires account to be taken of the need to mitigate and reduce, to a minimum, potential adverse impacts resulting from noise and to avoid noise giving rise to significant adverse impacts on health and the quality of life. The Noise Policy Statement for England includes the key aim for development to avoid significant adverse impacts. British Standard BS4142 ‘Methods for Rating and Assessing Industrial and Commercial Sound’ is typically used to measure the effects of existing and proposed noise levels. This indicates that adverse impacts are likely to be experienced where noise levels are recorded, at noise sensitive receptors, which are 5dB above background noise levels. 25. The proposal would include 20 battery housing containers each of which having two ventilation and cooling units. The Appellant’s Noise Assessment identifies that the main sound sources within the proposal would consist of 40 Heat, Ventilation and Air Conditioning (HVAC) units, 20 battery inverters and 11 transformers. The Assessment considered the effect of noise received at the 3 Landscape plan reference: 2701-01-13 4 Ecology Note, by Avian Ecology, dated 23/8/21 https://www.gov.uk/planning-inspectorate 5

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Appeal Decision APP/N5090/W/22/3298962 nearest noise sensitive receptors, being those properties of Hillview Road around 120 metres to the northwest of the site. Background noise level assessments were undertaken in three locations, with daytime noise levels ranging from 41-44dB LA90 and night-time noise levels of 36-37dB (15mins) LA90 . (15mins) 26. The Assessment’s predictive noise modelling uses data from plant similar to that proposed on site. The noise from the HVAC units would be principally caused by its axial fans. These would create a noise level that would cover a wide spectrum of the frequency band peaking at 71dB (at 500Hz). The Assessment explains that not all fans would be operating continuously, and most would not be in use to provide cooling during normal night-time temperatures. The transformers would generate noise levels of a maximum of 81dB (at the 500Hz range) and the inverters would create noise levels across the frequency range, peaking at 250Hz at 84dB. 27. The immission levels show the noise effects of the equipment as measured at four locations being Hillview Road, Planet House, Turpins and Partington Lane.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision These illustrate that due to distance and obstructions, the predicted noise levels, at these locations, would be 38dB, 33dB, 34dB and 36dB respectively. Notwithstanding that people respond differently to noise levels, the evidence indicates that the levels of noise generated by the plant at most times would not be louder than background noise levels. 28. One result demonstrates that noise levels would be marginally higher than background with Hillview Road experiencing a +1dB noise level increase during the night-time and within tolerances set out in BS4142. However, this increase would be below the adverse impact sought by the guidance and as such the development would have a negligible impact on noise levels. Furthermore, the noise limit assessment confirms that noise attenuation could reduce noise levels to 5dB below background noise levels. The method of assessment and its conclusions have been agreed with the Council’s Environmental Health Officer who has not objected to the development, and I see no reason to disagree with the Council in this regard. 29. Consequently, taking the above into consideration, I am satisfied that with attenuation the scheme could achieve noise levels 5dB below background.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision There would not be an adverse noise impact and consequently identify no conflict with the Framework. I am satisfied that the final specification of the associated plant, and its noise attenuation, could be determined by the imposition of a suitably worded planning condition. Lighting effects 30. The scheme would include lighting which would be necessary to support the CCTV security system as the facility would be largely unmanned. The lighting would comprise low-level directional shrouded LED lamps to restrict upward light spill to minimise disturbance to local wildlife and limit light pollution. Furthermore, due to its substantial distance from the nearest residential properties, the BSF would not have an adverse impact on the living conditions of nearby occupiers with respect to light pollution. Full details of lighting could be required by condition. https://www.gov.uk/planning-inspectorate 6

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Appeal Decision APP/N5090/W/22/3298962 Fire and health concerns 31. Interested parties have raised concerns that the facility may be vulnerable to fire, providing reference to fires that have occurred at other BSFs. The site is some distance from the nearest residential property and adjacent to an existing substation and therefore the risk of a fire effecting neighbouring residential areas would be minimal. Whilst the fire risks associated with the facility are not disclosed by the Appellant, there is no compelling evidence to demonstrate that the facility would be hazardous or incompatible with its location within the open countryside. In the unlikely event of a fire, the facility would be readily accessible by a fire tender and the Council has raised no concerns in this regard. As such, I see no clear reason in the evidence to illustrate why the facility would be especially vulnerable to the risk of fire. 32. Also, concerns have been raised that the proposed BSF could affect the health of local residents through the chemicals used in the facility. However, there is no clear evidence that such a facility would contain volatile chemicals or that it would result in harm to the local population in this manner.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Highway construction effects 33. The proposed development would generate some construction traffic. However, this would be temporary and once completed the facility would require minimal supervision during operation resulting in limited visits from an operator. As such, disturbance to local residents and traffic impact during construction and operation of the proposal would be limited. Furthermore, construction issues could be managed through the imposition of a construction management condition to further limit local disturbance. On this basis, the proposal would have a negligible effect on traffic levels in the local area resulting in no impact on highway safety, a conclusion supported by the Highway Authority. Flooding and drainage 34. Interested parties have raised concerns that the proposed facility may result in polluted battery or cleaning chemical compounds being drained into the local watercourse and that the site has been waterlogged in the past. The site is within flood zone 1 and is therefore the least likely land to flood. The proposed sustainable drainage system, as proposed with the Surface Water Drainage Assessment5, would include an infiltration trench and attenuation storage (if required).

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision This would limit discharge flow rates and prevent off-site flooding. Nothing in the evidence indicates that the proposal would result in contaminants being leached into the local ground. Most equipment would be housed within containers and the drainage system would capture runoff in infiltration trenches. As a result, arguments advanced in this regard are unsubstantiated. Therefore, the scheme would not result in adverse flooding or drainage impacts. Character and appearance 35. The site is within an enclosed area with mature tree groups found on three sides and adjacent to the raised ground of the existing substation. The nearest public vantage points are Partington Lane and Burtonhole Lane Bridleway. Views from these points would be extremely limited based on local screening and topography. Some views of the proposal may occur from a limited number 5 Surface Water Drainage Assessment, by KRS Environmental, July 2020 https://www.gov.uk/planning-inspectorate 7

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Appeal Decision APP/N5090/W/22/3298962 of residential windows and gardens. However, such views would already take in the existing substation. Views of the proposal would be over a substantial distance and partially screened by intervening landscaping resulting in no harm being caused to the outlook from private views. 36. The proposed plant would be low-lying in the enclosed local landscape. In combination with the limited scale of the security fence, and the screening formed by the retaining wall and landscaping, the proposal would not materially alter the character or appearance of the area. Other considerations Renewable energy 37. The Appellant identifies a national need for energy storage facilities. This both ensures energy security and assists the Country in achieving a net zero economy. The proposed BSF is required to improve energy storage. It would store power from the National Grid at times of excess supply and feed this back into the grid at times of high demand. The Appellant describes a clear linear relationship between the amount of renewable energy generation and energy storage. This is required to avoid curtailment and to maximise the use of renewable energy generation.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision It is especially important to accommodate the fluctuating nature of energy generated from renewable sources which is dependent on time of day and the weather, to support non-renewable sources of energy generation. 38. Therefore, whilst the proposal itself is not a renewable energy project per se it would provide enhanced energy resilience in the National Grid. As such, the energy to the proposed BSF would be generated by both renewable and non- renewable energy but over time it would provide greater support for renewable energy production. 39. A material consideration in the determination of planning proposals for renewable energy and associated facilities, are the National Policy Statements (NPS) for the delivery of major energy infrastructure. Both the existing and proposed NPSs state that these can be material considerations in decision making on applications that both exceed or sit under the thresholds for nationally significant projects. The NPSs recognise that large scale energy generating projects will inevitably have impacts, particularly if sited in rural areas.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision In September 2021, draft updates to the Overarching National Policy Statement for Energy (EN-1) and the National Policy Statement for Renewable Energy Infrastructure (EN-3) were published. 40. The draft NPS EN-1 states that: “There are several different types of electricity infrastructure that are needed to deliver our energy objectives. Additional generating plants, electricity storage, interconnectors and electricity networks all have a role, but none of them will enable us to meet these objectives in isolation6” and that “storage and interconnection can provide flexibility, meaning that less of the output of plant is wasted as it can either be stored or exported when there is excess production. They can also supply electricity when domestic demand is higher than generation, supporting security of supply7” 6 Draft National Policy Statement-EN1, paragraph 3.3.15 7 Draft National Policy Statement-EN1, paragraph 3.3.17 https://www.gov.uk/planning-inspectorate 8

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Appeal Decision APP/N5090/W/22/3298962 41. Accordingly, I am satisfied that the proposal would directly support the development of new energy generating facilities which will increasingly be delivered from renewable energy sources and therefore the proposal can be regarded as low carbon energy associated infrastructure. 42. The UK Government has declared a climate emergency and set a statutory target of achieving net zero emissions by 2050, and this is also a material consideration. Since the declaration, the Sixth Assessment Report of the Intergovernmental Panel on Climate Change has indicated that there is a greater than 50% chance that global temperature increases will exceed 1.5 degrees Celsius above pre-industrial levels. The report indicates that delay in global action to address climate change will miss a rapidly narrowing window of opportunity to secure a liveable and sustainable future for all8. 43. The UK Energy White Paper, Powering our Net Zero Future (2020), describes the costs of inaction as follows: “We can expect to see severe impacts under 3°C of warming. Globally, the chances of there being a major heatwave in any given year would increase to about 79%, compared to a 5% chance now.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Many regions of the world would see what is now considered a 1-in-100-year drought happening every two to five years. At 3°C of global warming, the UK is expected to be significantly affected, seeing sea level rise of up to 0.83 m. River flooding would cause twice as much economic damage and affect twice as many people, compared to today, while by 2050, up to 7,000 people could die every year due to heat, compared to approximately 2,000 today. And, without action now, we cannot rule out 4°C of warming by the end of the century, with real risks of higher warming than that. A warming of 4°C would increase the risk of passing thresholds that would result in large scale and irreversible changes to the global climate, including large-scale methane release from thawing permafrost and the collapse of the Atlantic Meridional Overturning Circulation. The loss of ice sheets could result in multi-metre rises in sea level on time scales of a century to millennia.” 44. The draft NSPs recognise that to meet the Government’s objectives and targets for net zero by 2050, significant large and small scale energy infrastructure is required.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision This identifies that “Storage has a key role to play in achieving net zero and providing flexibility to the energy system, so that high volumes of low carbon power, heat and transport can be integrated9”. It seeks solutions that include “maximising the usable output from intermittent low carbon generation10”. 45. Planning Practice Guidance (PPG), on renewable and low carbon energy, states that ‘there are no hard and fast rules about how suitable areas for renewable energy should be identified, but in considering locations, local planning authorities will need to ensure they take into account the requirements of the technology and critically, the potential impacts on the local environment, including from cumulative impacts.’11 8 IPCC Sixth Assessment Report - Summary for Policymakers, paragraph D.5.3 9 Draft National Policy Statement-EN1, paragraph 3.3.24 10 Draft National Policy Statement-EN1, paragraph 3.3.25 11 PPG, Paragraph: 005 Reference ID: 5-005-20150618 https://www.gov.uk/planning-inspectorate 9

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Appeal Decision APP/N5090/W/22/3298962 46. The Framework explains that when dealing with planning applications, planning authorities should support the transition to a low carbon future, improve resilience and support renewable and low carbon energy and associated infrastructure. Paragraph 158(b) also explains that such schemes should be approved if any impacts are, or can be made, acceptable. 47. This benefit weighs strongly in favour of the scheme. Locational requirements of the facility 48. The Appellant identifies that by 2050 energy storage will need to increase by between 23GW and 40GW, requiring 394-734 battery sites across the UK. The evidence demonstrates that battery storage facilities, of 50WM, must be located close to an existing transmission station that has a connection capacity to both export and import the requisite amount of electrical energy. Such facilities are very limited through the UK. 49. The Appellant’s site search report12 demonstrates that of the 298 Super Transformer Substations across the UK, only 168 could accommodate a 50MW battery facility. Twelve sites were considered within the north London search area.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision This found that no other stations within the search area have sufficient capacity to accommodate the proposal. Accordingly, the existing substation appears to present the only viable connection in the London area for the scale of development proposed and with access to the required transmission connected services. 50. Alternative sites for a battery facility were considered that could connect to the sub-station. However, this found that alternative sites, within the requisite 300 metres search area, would be elsewhere within the Green Belt or on sites where excessive additional costs would make the proposal unviable. As a result, I am satisfied that the site search assessment has demonstrated that an alternative site would not be readily available, which also weighs in favour of the proposal. Planning balance 51. I have concluded that the appeal scheme would result in harm to the Green Belt from inappropriateness, through encroachment and due to a moderate loss of openness, to which I afford substantial weight. The proposed scheme would not harm the SINC site, subject to suitable mitigating conditions.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Furthermore, the other matters identified raise issues that either result in no harm or raise technical matters that could be adequately addressed through the imposition of appropriate conditions to negate the harm. 52. Conversely, the proposed BSF would support the ongoing shift of power generation to renewable energy and help combat climate change. The appeal site is unobtrusive within a depression of land and in an enclosed site, that prevents public views of the site from the highway and bridleway. The surrounding landscape also includes the existing substation which is a large and utilitarian feature within the landscape. The natural and man-made features enable the area to accommodate a degree of change without causing harm to the character and appearance of the area. 12 Site Search, by Harbour Energy, September 2020 https://www.gov.uk/planning-inspectorate 10

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Appeal Decision APP/N5090/W/22/3298962 53. The Framework identifies that many renewable energy projects in the Green Belt will comprise inappropriate development. In such cases, developers will need to demonstrate very special circumstances which could include the wider environmental benefits associated with the increased production of energy from renewable sources. Whilst this lends support for renewable projects in the Green Belt it does not confer an automatic approval of such schemes. In such circumstances the effects of such development must take into account a broad range of issues in mind of the general presumption against inappropriate development and the resultant substantial harm conveyed to the Green Belt by this. 54. The benefits of the proposed BSF raise substantial public benefits that weigh in favour of the proposal. These benefits are recognised in the London Plan, in seeking increased energy efficiency and utilising low carbon energy sources, and guidance and national policy in accordance with the Climate Change Act of 2008.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision There is also clear support, in Section 14 of the Framework, to increase the use and supply of renewable and low-cost energy and to maximise the potential for suitable such development. The delivery of suitable renewable energy projects, and those that would support them, is fundamental to facilitate the country’s transition to a low carbon future in a changing climate. 55. Also, the BSF requires a transmission station that has a connection capacity to both export and import the requisite amount of electrical energy which are rare within the UK. As such, this requirement places a locational restriction on site selection that severely limits the number of appropriate sites. The Appellant has therefore demonstrated that a rational approach was taken to site selection lending support for the selected site. 56. The benefits identified attract very significant weight in favour of the scheme. These are of sufficient magnitude to outweigh the substantial harm found to the Green Belt. In this context, the harm to the Green Belt would be clearly outweighed by the other considerations identified and therefore the very special circumstances necessary to justify the development exist.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Accordingly, the proposal would satisfy the local and national Green Belt policies I have already outlined. Conditions 57. I have considered the use of conditions in line with the guidance set out in the PPG. I shall take into consideration the conditions within the Council’s Statement of Case and impose most of these with some amendments and adjustments for clarity. I have imposed the standard conditions with respect to timeframes and approved plans as advised by the PPG for clarity and certainty [conditions 1 and 2]. Also, a condition would be necessary to grant only a temporary consent to manage the overall impact of the development on the openness of the Green Belt [15]. 58. It is necessary for conditions to ensure that the external finishes of the plant and machinery and CCTV equipment adequately blends in with the verdant character of the site’s surroundings [3 and 14]. Conditions are necessary to require the submission of a noise and mitigation assessment of the selected plant and a post completion acoustic report in the interests of the living conditions of local residents [5 and 6].

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision It is also necessary to seek the submission of an environmental management plan due to the ecological interests of the site and to protect existing living conditions [4]. https://www.gov.uk/planning-inspectorate 11

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision It is also necessary to seek the submission of an environmental management plan due to the ecological interests of the site and to protect existing living conditions [4]. https://www.gov.uk/planning-inspectorate 11

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Appeal Decision Appeal Decision APP/N5090/W/22/3298962 59. Conditions are required to ensure that the approved landscaping scheme is undertaken, that the ecological measures are installed, and a lighting scheme agreed to ensure the delivery of biodiversity gain and to protect wildlife in compliance with DP policy DM16 [9 and 10]. It would also be necessary for a tree protection plan and underground servicing details to be agreed by condition in the interests of the character and appearance of the area [11 and 12]. Furthermore, a condition would be required to ensure that the construction equipment complies with emission standards in the interests of air quality in compliance with London Plan policy SI1 [7]. 60. I have not imposed the Council’s suggested condition with respect to the pre and post construction quality of the surfaces of nearby highways as this would be unnecessary to make the proposal acceptable in planning terms. Conclusion 61. For the above reasons, the appeal is allowed, and planning permission is granted subject to the conditions within the attached schedule.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Ben Plenty INSPECTOR Schedule of conditions 1) The development hereby permitted shall begin not later than three years from the date of this decision. 2) The development hereby permitted shall be carried out in accordance with the following approved plans: 2701-01-02 (Site Location Plan), 2701-01-03 Rev A (Statutory Plan), 2701-01-04b (General Arrangement), 2701-01-05 (Welfare / Control / Storage Container), 2701-01-06 (Battery Storage Container), 2701-01-07 (External Switchgear), 2701-01-08 (Switchroom Control Room), 2701-01-09 (Inverter & Transformer Station), 2701-01-10 (Auxiliary Transformer, Fencing, CCTV Cameras & Retaining Wall), 2701-01-13 (Landscape Design) and the Surface Water Drainage Assessment, by KRS Environmental (dated July 2020). https://www.gov.uk/planning-inspectorate 12

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Ben Plenty Appeal Decision APP/N5090/W/22/3298962 3) Prior to installation of the structures, including battery containers, storage and utility containers, generators and transformers and fencing, details of the external finishing colour of all elements shall be agreed in writing by the Local Planning Authority. The structures and fencing shall be retained and maintained in the agreed finish for the lifetime of the development. 4) Prior to Ground Works and Site Preparation Works, no development shall commence within a Development Phase until a Construction Environmental Management Plan, setting out the construction and environmental management measures associated with that Development Phase, has been submitted to and approved in writing by the Local Planning Authority. The details shall be in accordance with the Planning Design and Access Statement (PDAS) and shall include: i. Site information (including a site plan and management structure), ii. Description of works, equipment and storage, iii. Programme of works, iv. Temporary hoarding and fencing, v. Temporary works, vi. Interim drainage strategy, vii. Intrusive site investigation works and monitoring (the scope to be agreed in writing, with the Local Planning Authority), viii.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Ben Plenty Code of Considerate Practice, ix. Consultation and neighbourhood liaison, x. Staff training and briefing procedures, xi. Schedule of environmental legislation and good practice, xii. Register of permissions and consents required, xiii. Environmental Audit Programme, xiv. Environmental Risk Register, xv. Piling Works Risk Assessment, xvi. Health and safety measures, xvii. Complaints procedures, xviii. Monitoring and reporting procedures of Demolition and waste management, xix. Demolition Audit, xx. Site clearance and waste management plan, xxii. Construction traffic routes, xxiii. Construction traffic management (including access to the site; the parking of vehicles for site operatives and visitors; hours of construction, including deliveries, loading and unloading of plant and materials; the storage of plant and materials used in the construction of the development; the erection of any means of temporary enclosure or security hoarding and measures to prevent mud and debris being carried on to the public highway and ways to minimise pollution), xxiv. Ecology surveys and management plan in relation to any existing ecological features that may be affected by works in that Development Phase, xxv.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Ben Plenty Measures to minimise visual impact during construction, xxvi. Measures to minimise noise and vibration levels during construction, xxvii. Measures to minimise dust levels during construction, xxviii. Measures to control pollution during construction (including a Pollution Response Plan), xxix. Construction lighting strategy, including measures to minimise light spill, xxx. Measures to reduce water usage during construction, xxxi. Measures to reduce energy usage during construction, xxxii. Any other precautionary and mitigatory measures in relation to demolition and construction as identified in the PDAS. The development shall thereafter be implemented in accordance with the measures detailed within the statement. 5) No development other than land remodelling works and site assembly shall commence on site in connection with the development hereby approved until a report has been carried out by a competent acoustic consultant that assesses the likely noise impacts from the development of the ventilation/extraction plant, and mitigation measures for the https://www.gov.uk/planning-inspectorate 13

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Ben Plenty Appeal Decision APP/N5090/W/22/3298962 development to reduce these noise impacts to acceptable levels and has been submitted to and approved in writing by the Local Planning Authority. The report shall include all calculations and baseline data and be set out so that the Local Planning Authority can fully audit the report and critically analyse the content and recommendations. The measures approved under this condition shall be implemented in their entirety prior to the commencement of the use/first occupation of the development and retained as such thereafter. 6) Before the development hereby permitted is first brought into use, a post-completion acoustic report shall be submitted to and approved in writing by the Local Planning Authority. This report should confirm that all the noise mitigation measures to ensure compliance with the London Borough of Barnet noise standard for external plant have been implemented in their entirety. The development shall be implemented in full accordance with the details as approved under this condition prior to the first occupation and retained as such thereafter.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Ben Plenty 7) All Non-Road Mobile Machinery (NRMM) of net power of 37kW and up to and including 560kW used during the course of the site preparation and construction phases shall comply with the emission standards set out in chapter 7 of the GLA's supplementary planning guidance "Control of Dust and Emissions During Construction and Demolition" dated July 2014 (SPG), or subsequent guidance. Unless it complies with the standards set out in the SPG, no NRMM shall be on site, at any time, whether in use or not, without the prior written consent of the local planning authority. The developer shall keep an up-to-date list of all NRMM used during the demolition, site preparation and construction phases of the development on the online register at https://nrmm.london/. 8) The free-field Rating Level (as defined in BS 4142:2014+A1:2019) from all of the proposed plant hereby approved shall be at least 5dB(A) below the background level, as measured from any point 3.5 metres outside the window of any room of a neighbouring residential property.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Ben Plenty 9) All work comprised in the approved scheme of landscaping shall be carried out before the end of the first planting and seeding season following occupation of any part of the buildings or completion of the development, whichever is sooner, or commencement of the use. Any existing tree shown to be retained or trees or shrubs to be planted as part of the approved landscaping scheme which are removed, die, become severely damaged or diseased within five years of the completion of development shall be replaced with trees or shrubs of appropriate size and species in the next planting season. 10) The development shall proceed and be carried out in accordance with the findings and recommendations of the approved Ecological Assessment, Avian Ecology (dated May 2019), Ecology Note: Response to LPA Comments, Avian Ecology (dated 23/08/21) and the associated ecological surveys submitted in support of the application and the details of compensation measures and ecological enhancements contained within shall be incorporated into the finished scheme.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Ben Plenty 11) No development shall take place until details of the location, extent and depth of all excavations for services (including but not limited to electricity, gas, water, drainage and telecommunications) in relation to https://www.gov.uk/planning-inspectorate 14

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Ben Plenty 11) No development shall take place until details of the location, extent and depth of all excavations for services (including but not limited to electricity, gas, water, drainage and telecommunications) in relation to https://www.gov.uk/planning-inspectorate 14

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Ben Plenty Appeal Decision APP/N5090/W/22/3298962 trees on and adjacent to the site have been submitted to and approved in writing by the Local Planning Authority. The development shall thereafter be implemented in accordance with details approved under this condition. 12) No site works or development (including any temporary enabling works, site clearance and demolition) shall take place until a dimensioned tree protection plan in accordance with Section 5.5 and a method statement detailing precautions to minimise damage to trees in accordance with Section 6.1 of British Standard BS5837: 2012 (Trees in relation to design, demolition and construction - Recommendations) have been submitted to and approved in writing by the Local Planning Authority. No site works (including any temporary enabling works, site clearance and demolition) or development shall take place until the temporary tree protection shown on the tree protection plan approved under this condition has been erected around existing trees on site. This protection shall remain in position until after the development works are completed and no material or soil shall be stored within these fenced areas at any time.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Ben Plenty The development shall be implemented in accordance with the protection plan and method statement as approved under this condition. 13) Prior to the installation of any lighting within the site, a detailed lighting scheme including lighting levels at the boundary of the site shall be submitted to and approved in writing by the Local Planning Authority. Any lighting shall be carried out in accordance with the approved details. 14) Prior to its installation details of all CCTV infrastructure including height, colour and location of any mounted equipment shall be submitted to and agreed in writing by the Local Planning Authority. 15) The Battery Storage Facility shall be permitted for an operational life of 40 years and thereafter, a detailed decommissioning strategy shall be submitted to and approved in writing by the Local Planning Authority. This strategy shall identify the trigger point(s) for decommissioning the site at which time the site shall be restored to its previous state as agricultural land with all infrastructure (including structures, hardcore, concrete and any underground apparatus) to be removed in accordance with details to be agreed within the strategy.

National Grid Mill Hill Substation , Land west of National Grid Mill Hill Substation , Mill Hill, NW7 1NT — London Borough of Barnet — Ben Plenty Decommissioning and restoration of the site shall thereafter be carried out and completed in full accordance with the details approved under this condition within 12 months of the expiry of the 40-year operational life following the date of this permission. End of conditions https://www.gov.uk/planning-inspectorate 15