Vale of Glamorgan Replacement Local Development Plan 2021-2036: Deposit Plan Consultation – March 2026
Representations on behalf of National Grid Electricity Transmission (NGET)

National Grid Electricity Transmission has appointed Fisher German LLP to review and respond to local planning authority Development Plan Document consultations on its behalf. We are instructed by our client to submit the following representation with regard to the current consultation on the above document.

About National Grid Electricity Transmission (NGET)

National Grid Electricity Transmission plc (NGET) owns and maintains the electricity transmission system in England and Wales. NGET manage not only today’s highly complex network but also to enable the electricity system of tomorrow. Their work involves building and maintaining the electricity transmission network – safely, reliably and efficiently. NGET connect sources of electricity generation to the network and transport it onwards to the distribution system so it can reach homes and businesses.

National Grid Electricity Distribution (NGED) are the electricity distribution division of National Grid and are separate from National Grid Electricity Transmission’s core regulated businesses. Please also consult with NGED separately from NGET.

National Grid no longer owns or operates the high-pressure gas transmission system across the UK. This is the responsibility of National Gas Transmission, which is a separate entity and must be consulted independently.

National Grid Ventures (NGV) develop, operate and invest in energy projects, technologies, and partnerships to help accelerate the development of a clean energy future for consumers across the UK, Europe and the United States. NGV is separate from National Grid’s core regulated businesses. Please also consult with NGV separately from NGET.

National Energy System Operator (NESO) has taken over the electricity and gas network planning responsibility from National Grid Electricity System Operator Limited (NGESO) as of 1st October 2024. Early engagement with NESO is recommended in order to establish available supply capacity to any potential development sites and what, if any, reinforcement is required to ensure adequate continued supply. Please consult with NESO separately from NGET.

Proposed development sites crossed or in close proximity to NGET assets

Following a review of the above Development Plan Document, we have identified that one or more proposed development sites are crossed by or in close proximity to NGET assets. Details of the sites affecting NGET assets are provided below.

Development Plan Document Site Asset Description

Policy EMP1 (Employment Regeneration Opportunity Area 1) (site 433 on candidate sites map)
Aberthaw leasehold land
ABERTHAW 132KV S/S
ABERTHAW 275KV S/S
SGT2 275KV CABLE: ABERTHAW 275KV S/S
UPPER BOAT 1 275kV CABLE: ABERTHAW 275KV S/S
LL ROUTE: 275kv Overhead Transmission Line route: ABERTHAW – TREMORFA
ZZB ROUTE: 275kv Overhead Transmission Line route: ABERTHAW - UPPER BOAT 1 and ABERTHAW - UPPER BOAT 2
ZZS ROUTE: 275kv Overhead Transmission Line route: ABERTHAW - CARDIFF EAST – PYLE and ABERTHAW – PYLE

Candidate site 516 (Renewable Energy)
LL ROUTE: 275kv Overhead Transmission Line route: ABERTHAW – TREMORFA
ZZB ROUTE: 275kv Overhead Transmission Line route: ABERTHAW - UPPER BOAT 1 and ABERTHAW - UPPER BOAT 2
ZZS ROUTE: 275kv Overhead Transmission Line route: ABERTHAW - CARDIFF EAST – PYLE and ABERTHAW – PYLE

Candidate site 577 (Renewable Energy)
ZZB ROUTE: 275kv Overhead Transmission Line route: ABERTHAW - UPPER BOAT 1 and ABERTHAW - UPPER BOAT 2
ZZS ROUTE: 275kv Overhead Transmission Line route: ABERTHAW - CARDIFF EAST – PYLE and ABERTHAW – PYLE

Candidate site 513 (Renewable Energy)
ZZB ROUTE: 275kv Overhead Transmission Line route: ABERTHAW - UPPER BOAT 1 and ABERTHAW - UPPER BOAT 2
ZZS ROUTE: 275kv Overhead Transmission Line route: ABERTHAW - CARDIFF EAST – PYLE and ABERTHAW – PYLE

Candidate site 511 (Renewable Energy)
ZZB ROUTE: 275kv Overhead Transmission Line route: ABERTHAW - UPPER BOAT 1 and ABERTHAW - UPPER BOAT 2
ZZS ROUTE: 275kv Overhead Transmission Line route: ABERTHAW - CARDIFF EAST – PYLE and ABERTHAW – PYLE

Candidate site 517 (Renewable Energy)
LL ROUTE: 275kv Overhead Transmission Line route: ABERTHAW – TREMORFA

Candidate site 515 (Renewable Energy)
LL ROUTE: 275kv Overhead Transmission Line route: ABERTHAW – TREMORFA

A plan showing details of NGET assets is attached to this letter. Please note that this plan is illustrative only. NGET also provides information in relation to its assets at the website below.
https://www.nationalgrid.com/electricity-transmission/network-and-infrastructure/network-route-maps

NGET Electricity Network Infrastructure

The security and reliability of the UK’s current and future energy supply is highly dependent on having an electricity network which will enable the existing and new electricity generation, storage, and interconnection infrastructure that the country needs to meet the rapid increase in electricity demand required to transition to net zero, while maintaining energy security.

In general, NGET does not own the land crossed by its overhead lines but has responsibility for maintaining the equipment and safe supply of electricity. The increasing pressure for development is leading to more development sites being brought forward through the planning process on land that is crossed by NGET assets.

Despite this NGET is not a statutory consultee in the plan-making process but it is recommended that NGET are consulted at the earliest possible opportunity in order that advice and guidance can be taken into account on development near overhead lines, or wider policies that may affect the existing or future supply of electricity.

With the above context in mind, the Council should ensure that development proposals located near transmission assets demonstrate that they will not compromise safety, operability, maintenance access, asset replacement or future network expansion. The Council should safeguard existing and potential access routes required for the delivery and removal of Abnormal Indivisible Loads (AILs) associated with the construction, replacement and maintenance of transmission-scale equipment, including large transformers at strategic substations and resist development or highway alterations that would prejudice, constrain or render impractical AIL access unless suitable mitigation or alternative agreed routes can be secured.

Interactions Commentary

NGET advocates the high standards of design and sustainable development forms promoted through national planning policy and understands that contemporary planning and urban design agenda require a creative approach to new development around high voltage overhead lines and other NGET assets.

Policy EMP1 (Employment Regeneration Opportunity Area 1) (site 433 on candidate sites map)
A significant number of NGET assets – including substations – fall within Employment Opportunity Area 1, as designated within Policy EMP1. This site also appears as site 433 on the candidate sites map.

NGET do not consider that proposals of EMP1 are necessarily in conflict with these assets and are keen to ensure development is able to come forward even where its assets are present within or adjacent to an allocation. However, it is critical that the presence of these assets is suitably addressed within the supporting policy wording if Policy EMP1 is to be considered effective as otherwise the presence of NGET assets without appropriate acknowledgement will amount to significant constraints on site delivery. In particular, the electrical substations require 24/7 access including for ‘abnormal indivisible loads’ (AIL) and the land immediately surrounding them is also critical to their safe and secure functioning and to accommodate any change in future requirements which may arise.

It is acknowledged that, as part of masterplanning principles set out at 6.281, the policy already makes mention of existing infrastructure assets within the site and a need for a site layout to be developed that considers the sites existing infrastructure (including electrical substations) however we consider that the policy needs to go further and acknowledge the wider range of NGET assets that are within the site as well as more clearly establish how any future development needs to respond to the presence of NGET assets within the site. With this in mind, we propose the following wording, or wording to similar effect which directly references the full range of NGET assets and specific design guide and principles be added to the list of masterplanning principles as a separate point:

“Development will include a strategy for responding to the NGET Substations, Overhead and Underground Cable Routes present within the site which demonstrates how the NGET Design Guide and Principles have been applied at the masterplanning stage and how the impact of the assets has been reduced through good design.”

Without appropriate acknowledgement of the NGET assets present within the sites, Policy EMP1 should not be considered effective as it cannot be delivered as proposed; unencumbered by the constraints posed by the presence of NGET infrastructure. As such, NGET object to the policy as currently drafted.

Renewable Energy Candidate Sites

A number of ‘candidate sites’ as included on the candidate site mapping, as listed in the above table, have NGET assets interacting with them. Whilst it is not clear what their future role as part of the Local Plan will be (they do not currently form part of the Proposals Map as published), NGET are keen to highlight these interactions so that, as with Policy EMP1 above, suitable policy wording can be included as part of any future development options on these sites, should they emerge as allocations in the future.

New Infrastructure

Demand for electricity is expected to rise significantly as the way we power homes, businesses and transport evolves. As the UK transitions towards net zero, fossil fuels will be replaced by increasing volumes of low-carbon electricity, including from offshore wind and other renewable sources.

The UK Government has committed to achieving net zero emissions by 2050, requiring a balanced approach to greenhouse gas emissions and removals. Decarbonising the energy system is central to meeting this national objective.

National Grid Electricity Transmission (NGET) is delivering a range of infrastructure projects across England and Wales to support this energy transition and ensure that the transmission network can accommodate the rapid growth in low-carbon generation.

The way NGET generates electricity in the UK is changing rapidly, and NGET are transitioning to cheaper, cleaner and more secure forms of renewable energy. NGET need to make changes to the network of overhead lines, pylons, cables and other infrastructure that transports electricity around the country, so that everyone has access to clean electricity from these new renewable sources. These changes include a need to increase the capability of the electricity transmission system between the North and the Midlands, and between the Midlands and the South. It is also needed to facilitate the connection of proposed new offshore wind, and subsea connections between England and Scotland, and between the UK and other countries across the North Sea. Taking this context into account, In planning for the area the Council should:

• Safeguard all existing NGET transmission assets, including overhead lines, underground cables and substations.
• Support future reinforcement and expansion, including works required for the Great Grid Upgrade and other strategic national infrastructure projects.
• Ensure development proposals located near transmission assets demonstrate that they will not compromise safety, operability, maintenance access, asset replacement, or future network expansion.
• Safeguard existing and potential access routes required for the delivery and removal of Abnormal Indivisible Loads (AILs) associated with the construction, replacement and maintenance of transmission-scale equipment, including large transformers at strategic substations.
• Resist development or highway alterations that would prejudice, constrain or render impracticable AIL access, unless suitable mitigation or alternative agreed routes can be secured.
• Encourage early engagement with NGET to identify and resolve any potential impacts at the earliest possible stage of the planning process.

Protecting existing assets and enabling future network development will ensure that the Council contributes effectively to national decarbonisation targets while supporting local growth, resilience and energy security.

Further Advice

NGET is happy to provide advice and guidance to the Council concerning their networks. Please see attached information outlining further guidance on development close to National Grid assets.
If we can be of any assistance to you in providing informal comments in confidence during your policy development, please do not hesitate to contact us.
To help ensure the continued safe operation of existing sites and equipment and to facilitate future infrastructure investment, NGET wishes to be involved in the preparation, alteration and review of plans and strategies which may affect their assets. Please remember to consult NGET on any Development Plan Document (DPD) or site-specific proposals that could affect our assets.
We would be grateful if you could add our details shown below to your consultation database, if not already included.

Further Guidance

NGET is able to provide advice and guidance to the Council concerning their networks and encourages high quality and well-planned development in the vicinity of its assets.
Developers of sites crossed or in close proximity to NGET assets should be aware that it is NGET policy to retain existing overhead lines in-situ, though it recognises that there may be exceptional circumstances that would justify the request where, for example, the proposal is of regional or national importance.
NGET’s ‘Design guidelines for development near pylons and high voltage overhead power lines’ promote the successful development of sites crossed by existing overhead lines and the creation of well-designed places. The guidelines demonstrate that a creative design approach can minimise the impact of overhead lines whilst promoting a quality environment. The guidelines can be downloaded here: https://www.nationalgrid.com/document/345326/download
The statutory safety clearances between overhead lines, the ground, and built structures must not be infringed. Where changes are proposed to ground levels beneath an existing line then it is important that changes in ground levels do not result in safety clearances being infringed. National Grid can, on request, provide to developers detailed line profile drawings that detail the height of conductors, above ordnance datum, at a specific site.
NGET’s statutory safety clearances are detailed in their Technical Guidance Note ‘Third-party guidance for working near National Grid Electricity Transmission equipment’, which can be downloaded here: https://www.nationalgrid.com/document/349291/download
How to contact NGET
If you require any further information in relation to the above and/or if you would like to check if NGET’s transmission networks may be affected by a proposed development, please visit the website: https://lsbud.co.uk/