Frequently asked questions

National Grid sits at the heart of Britain’s energy system, connecting millions of people and businesses to the energy they use every day. We bring energy to life – in the heat, light and power we bring to our customer’s homes and businesses; in the way that we support our communities and help them to grow; and in the way we show up in the world. It's our vision to be at the heart of a clean, fair and affordable energy future.

We are working to build a cleaner, fairer, and more affordable energy system that serves everyone – powering the future of our homes, transport and industry. We believe by acting now, the UK can become the world’s first major clean economy, creating growth and jobs for communities across Britain.

National Grid is a group of companies, and one of those companies, National Grid Electricity Transmission, owns, builds and maintains the network in England and Wales. It's National Grid Electricity Transmission that's developing plans for the Norwich to Tilbury upgrade.

Within the National Grid Group there are other distinctly separate legal entities, each with their individual responsibilities and roles. More information about National Grid can be found on the about us section of National Grid’s website.

National Grid Electricity Transmission owns, builds and maintains the high-voltage electricity transmission network in England and Wales. This network operates primarily at 400 kilovolts (kV) and 275 kV.

It's National Grid Electricity Transmission that is developing plans for the Norwich to Tilbury reinforcement and is the electricity transmission arm within National Grid.

National Grid ESO is the Electricity System Operator for Great Britain. The ESO makes sure we all have the essential energy we need by ensuring supply meets demand every second of every day.

Generators of electricity apply to National Grid ESO when they wish to connect to the high-voltage electricity network and the ESO leads the work to consider how the network may need to evolve to deliver a cleaner greener future. The ESO is legally separate from the rest of National Grid.

The Great Grid Upgrade is the largest overhaul of the grid in generations – making sure that renewable energy can move from where it’s generated to where it’s needed, enabling us all to power the things we love with cleaner energy.

Find out more about The Great Grid Upgrade

Norwich to Tilbury is a proposal for the development of new high voltage electricity infrastructure in East Anglia, including new overhead lines and underground cables, substation improvements and a new substation.

We need to develop the project because the existing transmission network in East Anglia doesn’t have sufficient capacity to manage the expected increase in offshore wind needing to connect in the coming years and beyond. 

By developing the project, we would be able to connect new sources of low carbon energy to homes, businesses and public services across in East Anglia and across  UK and help reduce our reliance on fossil fuels. In doing so, it would play a key role in addressing the climate emergency and help achieve the UK’s targets for net zero.

The high-voltage electricity network between Norwich and Tilbury needs to be reinforced to accommodate the changes in how we produce and use energy. The UK is currently working towards a target of reaching net zero by 2050 and a key part of reaching this is to increase our wind energy generation to 50 gigawatts (GW) by 2030. This would be enough to power every home in the UK with clean, renewable energy. 

Norwich to Tilbury is a vital part of this transition. By the end of the decade, there could be as much as 18 GW of new, cleaner electricity – enough to power around 18 million homes – connected into the East Anglian network. Ensuring this energy can reach the homes and businesses that need it means we need to deliver a significant amount of improvement to the onshore electricity infrastructure, much of which was built to accommodate less demand.  

The existing network in East Anglia was built in the 1960s and while it has been successful in meeting demand to date, achieving government targets for renewable and low-carbon energy requires a significant overhaul and upgrade of the electricity transmission network.

We are already carrying out work to reinforce and upgrade the existing network in East Anglia, but even with these upgrades, the network will not be sufficient for the amount of new electricity connecting to it.

As a result, our proposals for a new overhead line between Norwich and Tilbury are essential in supporting the wider UK transition to renewable energy.

There is no fully offshore solution to connect offshore wind to the grid and we have to bring the power onshore somewhere. Our job is to carefully consider the most feasible options and present proposals for public consultation. In doing this, we must consider impacts on local communities and the environment and deliver value for electricity consumers.

We have assessed an equivalent offshore option and to deliver the same capacity as the overhead line, we would need to build three subsea cables and associated onshore infrastructure.  This would mean significant extra cost to consumers, and that would not meet the requirements placed on us.

In addition to cost, there are a range of environmental factors and other onshore and offshore impacts which need to be considered in this option. Taking all these considerations into account we have concluded that an onshore connection is the most appropriate solution. 

We need to consider national policy statement EN-5 which covers the development of new energy infrastructure. This policy concludes that in most cases, the government expects that overhead lines will be appropriate and should be used as standard to reinforce the grid.

Our assessments have shown that undergrounding, including using HVDC cables, would be significantly more expensive and would have environmental impacts and would present engineering  challenges . Due to the higher price that would be involved in an underground alternative, we do not believe that this would be the most suitable option as all costs ultimately go onto domestic energy bills. 

Our proposals do include several uses of underground cabling in areas such as the Dedham Vale National Landscape. In all areas where we are considering underground cables, we have assessed the local environment and habitats to reduce the impacts as far as possible. 

The Treasury Green Book provides guidance on the interpretation by public servants of public spending, assets and resources for projects, policies and spend from the public purse. This doesn’t apply to us. We follow national guidance, primarily the National Policy Statement EN-5 (National Policy Statement for Electricity Networks Infrastructure), which doesn’t specify application of the Treasury Green Book.

We follow a robust assessment process, which we believe is appropriate for projects like this. Our assessments, strategy, plans and recommendations all come under Ofgem regulation and approval. Ultimately, our processes will be assessed and tested by the Planning Inspectorate and the relevant Secretary of State. The Treasury Green Book guidance has never been used for any DCO and isn’t applicable to this project.

The Electricity System Operator (ESO) – a separate part of National Grid – published a preliminary report in December 2020 on various strategic options (Offshore Coordination Phase 1 Report). This preliminary analysis only considered issues at a high-level and has been comprehensively superseded by subsequent assessments, which clearly indicate that an onshore connection would provide best value to consumers.

The ESO has since given this project the go ahead through its Network Options Assessment process (NOA). ESO’s NOA process assesses the costs and benefits of reinforcements and provides recommendations on which project should receive investment – and when.

It’s also incorrect to assert that an offshore grid is ‘greener’. All developments have environmental impacts that need to be assessed, managed and mitigated.

Different pylon designs in use in the UK include :

• standard lattice
• lower height lattice
• T-pylons

We’re carrying out further assessments on the pylon design that could be used for Norwich to Tilbury. Our assessments will include visual impacts and mitigation, environmental and ecological considerations, construction and lifetime maintenance effects.

No. We still need to build a new network reinforcement to connect other new offshore wind and new generation in the area.

These projects take many years to develop and there are often changes to the amount of generation needing to connect. A full list of contracted generation connecting into the region can be found in the Strategic Options Backcheck and Review 2023.

Any confirmed changes to connection contracts are factored into our back check and review process.

On 5 December 2023, the Department for Energy Security & Net Zero (DESNZ) announced funding, the Offshore Coordination Support Scheme (OCSS) to a consortium formed of National Grid’s Sea Link project and both the North Falls and Five Estuaries offshore windfarm projects. The funding is to investigate a coordinated design for offshore energy transmission and to learn lessons to inform future projects. 

The consortium is undertaking a series of studies and assessments to determine the feasibility, challenges and solutions of a coordinated offshore connection. This work will consider the economics, engineering and regulatory challenges as well as the logistics and programme delivery aspects.

The consortium members are continuing to develop each of their onshore Development Consent Order (DCO) proposals in parallel with the coordination studies. Until we know the outcome of those studies, it is important that we continue to develop our proposals for Norwich to Tilbury to meet our statutory duties and responsibilities to deliver the new renewable sources of energy to homes and business across the UK.

The ESO East Anglia Network Study is an Independent assessment which the Electricity System Operator (ESO) delivered to consider the consequential infrastructure impacts should the Government decide to take the OCSS forward.

The ESO study took a fresh look at the drivers for network reinforcement in East Anglia, alongside the various considerations that need to be taken into account. This includes the requirement for us to develop proposals that represent value for money to consumers, while being in line with current planning policy, environmental legislation and our licence obligations.

We remain committed to carefully considering the findings from the ESO Study and should it indicate feasible alternative infrastructure options, which still enable us to meet the obligations placed upon us, we will engage with the impacted communities accordingly.

We await the Government’s decision on the outcome of the first phase of this OCSS, and will ensure backcheck and review our proposals for Norwich to Tilbury to ensure we reflect this within the ongoing development of our East Anglian projects. 

In the meantime, to ensure we remain compliant with our legal obligations to connect customers and aligned with the OCSS guidance, we are continuing to progress the development of the existing East Anglian network projects, including the Norwich to Tilbury project.

An independent review of the strategic options appraisal by National Grid for the Project was carried out by Hiorns Smart Energy Networks. The report was commissioned by Essex County Council, Norfolk County Council and Suffolk County Council and reviewed the need and timing for additional electricity transmission capacity out of the East Anglia region by 2030. 

The report supports National Grid’s position that there is a need for additional electricity transmission capacity to facilitate renewable and low carbon energy generation development in the East Anglia region. It did not support National Grid’s programme delivery date of 2030 and argued that that the need for additional transmission capacity would more likely be closer to 2035 and that National Grid could delay progressing the Project for at least five years. 

We have carefully reviewed the report and its appraisals, and we note that the report is a significant and independent study of our proposals. We welcome the report’s support of the need for improvements to the transmission network and recognition that an offshore solution would result in significantly higher costs and provide lower capacity than the Norwich to Tilbury onshore proposals. 

However, we do not accept the report’s conclusions around the timing of need for additional capacity being closer to 2035 than 2030. National Grid is legally obliged (under our Transmission Owner Licence) to provide capacity at the dates formally agreed in contracts with energy generators (or customers). Contract dates are set out by ESO independent of National Grid. 

We have undertaken backchecks to ensure the capacity required in the contracts is consistent with our understanding of need (see our Strategic Options Backcheck Report 2024 for details). These backchecks also review the progress energy generators are making with planning consents for their projects. 

The Treasury Green Book provides guidance on the interpretation by public servants of public spending, assets and resources for projects, policies and spend from the public purse. This doesn’t apply to us. We follow national guidance, primarily the National Policy Statement EN-5 (National Policy Statement for Electricity Networks Infrastructure), which doesn’t specify application of the Treasury Green Book.

We follow a robust assessment process, which we believe is appropriate for projects like this. Our assessments, strategy, plans and recommendations all come under Ofgem regulation and approval. Ultimately, our processes will be assessed and tested by the Planning Inspectorate and the relevant Secretary of State. The Treasury Green Book guidance has never been used for any Development Consent Order (DCO) and isn’t applicable to this project.

We are consulting on our proposals for Norwich to Tilbury for ten weeks from 12.00 noon on Wednesday 10 April to 11.59pm on Tuesday 18 June 2024.

This is our third public consultation on our proposals. It is a statutory consultation because it is being carried out in line with the formal requirements of the Planning Act 2008. It follows our previous non-statutory consultations on our draft proposals which were held in 2022 and 2023.  

To provide feedback on our proposals:

• complete the feedback questionnaire available here
• email your comments to: [email protected]
• post your written responses (no stamp required) to: FREEPOST N TO T
• complete a printed feedback form and return it using the freepost address.

Comments must be received by 11.59pm on 18 June 2024.

During the consultation we are holding a series of public information events. These events will include information about our proposals, with copies of maps and technical documents available to view. Members of the project team will be available to answer questions about our proposals.

We are also holding six online webinar sessions, two of which will cover a general overview of our proposals. The other four will be section specific. You can attend any webinars you feel are relevant to you.

See our schedule of events and register for a webinar. 

The feedback we receive is important in helping us refine our proposals and understand the issues and concerns that communities have. At each stage of consultation, we publish a feedback report summarising the feedback and themes received and providing our responses to them. 

We have published feedback reports following the 2023 and 2022 non-statutory consultations. These are available to read in the Document Library. 

After we have completed this consultation, we will collate and analyse all feedback received and take it into account as we refine the Project’s design.

The feedback reports from all our public consultations will be included in the Project’s Development Consent Order (DCO), which will be submitted to the Planning Inspectorate.

As our current plans propose more than 2 kilometres (km) of overhead line, we expect the Project would be classified as a Nationally Significant Infrastructure Project (NSIP) under the Planning Act 2008. This means we need to apply for a type of planning consent called a Development Consent Order (DCO) to build and operate it. 

Once the DCO application is submitted, the Planning Inspectorate on behalf of the Secretary of State, has up to 28 days to decide whether or not the application meets the standards required to be accepted for examination.

If the application is accepted, it will go through a six-month examination period.  Careful consideration is given by the Examining Authority, including to all relevant and written representations, and supporting evidence. The Examining Authority is the Inspector or the Panel of Inspectors appointed to conduct the Examination of the application for the DCO.

The Planning Inspectorate must prepare a report on the application and submit this to the Secretary of State, including a recommendation, within three months of the close of Examination. The Secretary of State has a further three months to make a decision on whether to grant or refuse development consent. 

Our latest proposals for Norwich to Tilbury include:

• the preferred draft alignment for a new 400 kV electricity transmission connection of around 184 km running from Norwich Main Substation to Tilbury Substation via Bramford Substation including approximately 159 km of new overhead line and approximately 25 km of underground cabling
• six new Cable Sealing End (CSE) compounds (where high-voltage underground cables join onto an overhead line) and associated permanent accesses
• a new East Anglia Connection Node (EACN) 400kV substation, with a new permanent access on the Tendring Peninsula
• an alternative design at Waveney Valley, substituting approximately 2 km of pylons with underground cabling
• substation extension works at the existing Norwich Main, and Bramford substations and works within the existing Tilbury Substation
• temporary works including access roads, tracks, compounds and associated with the project’s construction.

We are also consulting on the preliminary findings from our environmental studies and assessments as well as proposed mitigation. Our proposals are presented in more detail on this website and in the Project Background Document 2024. 

The baseline for our proposals at the Waveney Valley is the use of overhead lines.

In response to feedback from the 2023 consultation, we are also considering proposals for a section of underground cables, known as the Waveney Valley Alternative.

 The Waveney Valley Alternative proposals would include:   

• installation of approximately 2 km of underground cabling (with 2 km of overhead line being removed from our proposals); and  
• two CSE compounds (to join the high-voltage underground cables to the overhead line) with associated access roads. This would increase the number of CSE compounds from six to eight. 

All other works not listed above would be the same for both the overhead line and underground cable designs in this area.

We are asking for feedback on both alternatives (overhead lines and underground cables) at this consultation.  

Building the project would involve a range of temporary construction activities. These would include preparing land and creating temporary haul roads to access work areas as well as providing temporary areas to store materials, vehicles and staff welfare facilities. 

To see how we build overhead lines, underground cables and haul roads, watch the animations available at nationalgrid.com/norwich-to-tilbury. 

More information on construction requirements can also be found in the Project Background Document 2024 and we welcome views and comments as part of this consultation.

We are proposing to build standard steel lattice pylons for this project. This pylon design is common across the electricity system in the United Kingdom. These would typically be around 50 metres with three sets of cross arms and each pylon would be designed for its location.

The suitability of other pylon designs, including T-pylons, is being reviewed and considered, with an initial assessment indicating that T-pylons would not be suitable. You can read more about this in the Design Development Report: Appendix B – Consideration of Pylon Options.  

New Cable Sealing End (CSE) compounds would be needed to connect the overhead lines to the underground cables. We are proposing a total of six CSE compounds with associated permanent access at the following locations. one north of the Dedham Vale National Landscape 

• two near Great Horkesley
• two near Fairstead
• one near Tilbury.

The Waveney Valley Alternative would introduce a further section of underground cabling and two additional CSE compounds.  

The Project is an Environmental Impact Assessment (EIA) development as defined by the EIA Regulations. As part of the consultation, we are seeking views on the potential environmental effects of the proposals and whether consultees have suggestions for reducing these effects (for example, through mitigation measures). This information is detailed in the Preliminary Environmental Information Report (PEIR). An Environmental Statement will be prepared in accordance with the EIA Regulations and will accompany the application for a Development Consent Order. 

We will also be required to ensure a 10 per cent biodiversity net gain (known as BNG). This means our work needs to result in more, or better quality, natural environment than before development. This opens up real opportunities to use development to enhance our wild spaces and provide new habitats. 

For more information on our work to protect the environment, we’ve developed a short video which you can view at the bottom of our Document Library. 

We have been asked why we are not planning to use superconductor technology, which can conduct electric energy without losses at temperatures above Absolute Zero Kelvin.

Alternating current (AC) High Temperature Superconductors (HTS) cannot currently provide the capacity, voltage level, or distance required by Norwich to Tilbury. Norwich to Tilbury would operate at 400 Kilovolts (kV) and HTS technology operates at voltages well below 400 kV. It is also generally more suited to urban constrained environments.

More widely, National Grid Group is involved in the development of AC superconducting technology. The group is made up of a number of companies of which National Grid Electricity Transmission is one. National Grid USA also owns a superconductor circuit in Albany, New York. This AC superconductor was one of the first in the world and is 350 m long, operating at 34.5 kV with a current rating of 800 A. It operates in a very congested urban area. 

As part of National Grid’s involvement in the development of AC superconducting technology, National Grid Electricity Transmission has recently partnered with Nexans, a cable manufacturer, and American Super Conductors to investigate possibilities for superconducting cable projects within the UK. 

We are carrying out noise and vibration assessments in line with our Environmental Impact Assessment to identify areas of potential noise disruption – both during the construction and ongoing operation of any new infrastructure. Where needed, we will develop noise barriers to try to minimise this sound disruption as much as possible. 

All of our machinery is compliant with industry standards and the limits on noise disruption that this entails. We have also included this in our routeing and planning to try and avoid neighbourhoods, hospitals, and schools, to ensure that these places receive minimal noise disruption.

National Grid takes the issue of health very seriously and relies on authoritative and independent scientific organisations, such as the World Health Organization (WHO) and the UK Health Security Agency (UKHSA), to review the worldwide body of scientific evidence on electric and magnetic fields (EMFs) and health, as well as reviewing the science ourselves.

We believe it is right that the decision on what is acceptable or not is made independently of industry. We ensure that all our assets comply with the guidelines set by Government on advice from the UK Health Security Agency (UKHSA).

A vast amount of research has been done into the possibility of health effects, without establishing any risks below these levels set by the guidelines.

If you would like to discuss a concern, please call the EMF helpline on 0845 702 3270 or email [email protected]

As required under the Planning Act 2008, we are holding a statutory consultation for ten weeks from 12.00 noon on Wednesday 10 April to 11.59pm on Tuesday 18 June 2024.

We aim to submit our Development Consent Order application in 2025, with examination and a decision on our application due to take place during 2025 and 2026. 

View our project timeline.

Construction would take approximately three years. If our application for consent is successful, we would aim to begin construction in 2027 and conclude around 2030, to be fully operational by 2031.

Our surveying involves the drilling of boreholes or the excavation of trial pits in order to assess ground conditions in some areas of the route. These types of surveys are called Ground Investigation (GI) works and are used to determine which soils and rocks are present in the area. They are also used to monitor the types and quantities of water, gas and vapour, which may be present in the ground.

GI works for Norwich to Tilbury are undertaken by National Grid’s appointed contractors. The information gathered during these surveys will be used to identify and understand engineering constraints, the ecology of the area and any environmental considerations that could influence the routeing of the new electricity transmission infrastructure.

After GI works are completed the land is returned to use and any samples gathered are tested, with the data and results forming part of our Environmental Statement (ES), which will be submitted as part of the suite of documents that form our Development Consent Order (DCO) application.

Some ecological and environmental surveys can only be carried out at specific times of the year. For example, wintering bird surveys are usually carried out between November to February, as they determine the species and numbers of birds which migrate over this season. Throughout the autumn and winter 2023/24, we’ll be carrying out GI studies. These studies started in October 2023 and will continue – depending on weather conditions – for around six months.

Other surveys will continue until the DCO application is submitted. 

National Grid tries to reach voluntary agreement to access the land for surveys whenever possible.

If agreement to access land for surveying cannot be reached voluntarily, Section 172 of the Housing and Planning Act 2016 authorises National Grid as an acquiring authority. It allows entry to survey land where there is a proposal to acquire an interest in or right over land.

We’ve also notified local authorities where work is taking place. Although we don’t need planning permission for this work, we believe it’s right to notify the local authority.

Allowing National Grid access to land does not stop the landowner making representations about the project at any time and allowing us access for surveys does not affect any rights to comment in any form.

We recognise the potential for land damage and disturbance that may be caused by carrying out surveys and site investigations and will make advanced compensation payments to landowners for a set period of time. Further information on payments that will be made on survey access is available within our Payments schedule for new electricity transmission assets.

National Grid will work with you and/or your agent to reach an agreement to carry out surveys. We endeavor to reach all agreements voluntarily.

Where an agreement in relation to taking access to land for engineering, ecological and environmental surveys cannot be reached voluntarily, Section 172 of the Housing and Planning Act 2016 authorises National Grid as an acquiring authority. It allows entry to survey or value land where there is a proposal to acquire an interest in or right over land.

National Grid will look to agree easements (permanent agreement to install, use and maintain equipment and assets) with all affected landowners, allowing National Grid to install, use and maintain their equipment.

An easement is a legal right in perpetuity, granting National Grid the right to install, use and maintain its equipment. A permanent easement is granted in exchange for a one-off capital payment, also known as a Deed of Grant of Easement.

A Wayleave is a licence granted by the owner and occupier of land giving National Grid the right to install, use and maintain its equipment. Terms of the wayleave agreement provide for the annual rental and compensation payments to be made based on the type and amount of infrastructure on the land, and its land use.

Easement payments vary between types of land and whether the new connection will be an overhead line or underground cables. For more information on both, please read National Grid's Payments schedule for new electricity transmission assets.

An option agreement is a legally binding document used by National Grid to secure land rights. The option will obligate the parties involved to enter into a final form of agreement as long as the relevant terms and conditions of the option agreement are met.

National Grid may have to rely on compulsory purchase powers as a last resort, if voluntarily agreements for land rights cannot be reached with landowners. When submitting the Development Consent Order (DCO) application, National Grid will also apply for compulsory purchase powers. This will ensure that, if the DCO is granted, National Grid will be able to obtain all land rights needed to construct and subsequently operate the new electricity transmission assets.

National Grid acknowledges that any proposed new works may cause concern to landowners. In additional to the other payments outlined, ‘Injurious affection’ and any other appropriate Heads of Claim will be considered on an individual basis in accordance with current legislation.

We recognise that the visual impact of any new overhead infrastructure is likely to be a significant issue for many local communities, so we always try to avoid communities and individual properties as much as possible.

However, UK law does not require us to compensate for loss of view.

The Government has recently consulted on how local communities could benefit from the development of network infrastructure in their area. We welcome this recognition of the importance of those communities and await the outcome of the consultation.