Frequently asked questions (FAQs)

Here you’ll find answers to some of the most frequently asked questions about the Bramford to Twinstead reinforcement.

We’ll keep these up-to-date as our work progresses and we hope they answer your questions about our work.

 

General information

What is National Grid Electricity Transmission?

National Grid Electricity Transmission, owns, builds and maintains the high-voltage electricity transmission network in England and Wales.  In England and Wales, the high voltage network operates primarily at 400,000 volts (400 kV) and 275,000 volts (275 kV).

It is National Grid Electricity Transmission that is developing plans for the Bramford to Twinstead reinforcement and are the electricity and transmission arm within National Grid. Within the National Grid Group there are distinctly separate legal entities, each with their individual responsibilities and roles. More information about National Grid can be found on page 6 of our project background document.  

What is National Grid ESO?

National Grid ESO is the Electricity System Operator for Great Britain. Generators of electricity apply to National Grid ESO when they wish to connect to the high-voltage electricity network. National Grid ESO leads the work to consider how the network may need to evolve to deliver a cleaner greener future. National Grid ESO is a separate legal entity from National Grid Electricity Transmission.

What is National Grid Ventures?

National Grid Ventures sit outside the core regulated National Grid businesses, investing in technologies and partnerships that help accelerate the UK’s move to a clean energy future. This includes interconnectors, which are undersea cables that connect the UK with countries across the North Sea, allowing trade between energy markets and efficient use of renewable energy resources.

What are National Grid's policies when working in the UK?

National Grid’s commitments when undertaking works in the UK can be found in our stakeholder, community and amenity policy found here: commitments when undertaking works in the UK.

What are National Grid Electricity Transmission's (NGET) responsibilities within the electricity industry?

When developing transmission network proposals, we have a statutory duty, under the Electricity Act 1989, to act in an efficient, coordinated and economical way, and have regard to the desirability of preserving amenity.

When considering options to deliver additional electrical network capability, we must balance the need to develop the network in a way that is efficient, coordinated and economical, and minimises impacts on people and places.

How is National Grid regulated?

In the UK, energy networks are regulated by Ofgem, the Office of Gas and Electricity Markets. Ofgem operate under the direction and governance of the Gas and Electricity Markets Authority. It has established price control mechanisms to ensure that the investment required to maintain a reliable and secure network is delivered at a fair price for consumers.

Our shared are listed on the London Stock Exchange and as such, we are also regulated by the Financial Services Authority in the UK.

What is the Department for Business, Energy and Industrial Strategy?

The Department for Business, Energy & Industrial Strategy (BEIS) , is a ministerial department responsible for business, industrial strategy, science, research and innovation, energy and clean growth, and climate change. BEIS are looking to build a stronger, greener future through innovation.

Following the Government’s ‘Ten Point Plan for a Green Industrial Revolution’ in December 2020, BEIS published an energy white paper entitled ‘Powering our Net Zero Future’, which sets out how the UK will clean up its energy system and reach net zero emissions by 2050. BEIS works alongside Ofgem in setting the framework within which National Grid ESO, National Grid Electricity Transmission and the wider energy sector operates.

What is Ofgem?

Ofgem (the Office of Gas and Electricity Markets) is the government regulator for gas and electricity markets in Great Britain. Ofgem is a non-ministerial government department and an independent National Regulatory Authority, whose role is to protect consumers through delivering a greener, fairer, energy system. Ofgem works with the government, industry and consumer groups to help deliver a net zero economy at the lowest cost possible to consumers.

What is the Crown Estate?

The Crown Estate is an independent commercial business, created by an Act of Parliament, with a diverse portfolio of UK buildings, shoreline, seabed, forestry, agriculture and common land. The Crown Estate is responsible, among other things, for seabed leasing for offshore wind.

How does UKPN fit with the Bramford to Twinstead Reinforcement?

UK Power Networks (UKPN) owns and operates the regional distribution network which makes up the 132 kV and lower voltage wires and cables that take power from National Grid’s substations and deliver it to homes and businesses in the region. Some smaller scale generation also feeds power into the National Grid network via the regional distribution network.

The Bramford to Twinstead reinforcement includes removing approximately 25 km of UKPN existing 132 kV overhead line from Burstall Bridge to the ‘diamond crossing’ near Twinstead. In order to do this, National Grid proposes to build a new grid supply point substation south of Sudbury, which would allow UKPN to continue to distribute power to local homes and businesses.

Electricity Generation and Transmission in the UK

What are energy generators and energy suppliers?

Generators produce electricity from renewable infrastructure such as wind turbines and solar arrays, or from more traditional power stations using other fuel sources such as low carbon nuclear or gas. Generators produce the electricity that we all use in our homes and businesses. Electricity generators trade the electricity they make to electricity suppliers. Electricity is also traded between neighbouring countries using interconnectors. Electricity is also traded between neighbouring countries using interconnectors.

Electricity suppliers buy the electricity in the wholesale market from electricity generators and supply to homes and businesses (end customers). The electricity supplier is the company you pay your electricity bill to. You can choose your electricity supplier and they set the tariff for the electricity you use. Electricity is also traded between neighbouring countries using interconnectors.

How does electricity transmission work?

Generators produce electricity which is then transported using the electricity transmission network, along overhead lines supported on pylons and underground cables, and through substations, designed to carry electricity long distance at high voltage. In England and Wales, it operates primarily at 400,000 volts (400 kV) and 275,000 volts (275 kV).

What is offshore wind and why are more offshore wind farms being developed?

Offshore wind power or offshore wind energy is the energy taken from the force of the winds out at sea, transformed into electricity and supplied into the electricity network onshore.

The government’s Energy White Paper ‘Powering our Net Zero Future’ in December 2020 sets a target to deploy 40 GW of offshore wind by 2030 – enough to power every home.

The Climate Change Committee anticipate that electricity demand will at least double by 2050 as we shift to clean energy to drive electric vehicles, heat our homes and power our industry.

The Committee’s Sixth Carbon Budget ‘The UK’s path to Net Zero’ published in December 2020 recommends deploying 40 GW of offshore wind by 2030, rising to as much as 140 GW of offshore wind by 2050.

How long do offshore wind farms last?

National Grid Electricity Transmission doesn't build wind farms, but it is generally accepted that a good quality modern turbine has a design life of about 20 years. Good maintenance may extend that to 25 years or longer and offshore wind farms may be designed such that the turbine structure above the waves can be replaced at the end of its design life.

What are interconnectors?

Interconnectors are usually high voltage direct current cables that are used to connect the electricity systems of neighbouring countries. Interconnector runs under the sea, underground or via overhead cabling, to connect the electricity systems of two countries. They allow electricity to be traded between the market in Great Britain and the continent, ensuring energy resources are used efficiently by the sharing of surplus electricity, benefiting consumers in the UK and Europe by providing flexibility to import more affordable and renewable or low carbon sources of electricity, helping keep end-user bills as low as possible, helping reduce emissions and aiding security of supply.

National Grid Ventures already operate interconnectors linking Britain with France, Belgium, the Netherlands and Norway – powering 6.4million homes with clean energy each year. By 2030 90% of the energy imported by our interconnectors will be from zero carbon energy sources.

What work is being undertaken by National Grid to improve or extend the undersea interconnector system with European countries?

The UK is already connected by electricity interconnectors linking us to France, Belgium, The Netherlands and Norway. Each year those can provide enough capacity to power 6.4 million homes with clean energy. National Grid Ventures is currently building a further interconnector linking Great Britain with Denmark which will have enough capacity to power a further 1.4 million homes. By 2030 90% of the energy imported by our interconnectors will be from zero carbon energy sources. The Government note in the Energy White Paper ‘Powering our Net Zero Future’ that a higher level of interconnector capacity could decrease cumulative emissions in Great Britain by up to 199MtCO2e by 2050, as well as reducing total system costs.

Find out more about how interconnectors will, in future, potentially also connect offshore wind farms here.

How does National Grid help the UK’s journey to net zero?

The Government has made it clear that a key part of the pandemic recovery is building back cleaner and greener. The UK has set a world-leading target to tackle climate change, which is to achieve Net Zero by 2050. Put simply, this means that we remove the same amount of greenhouse gas from the atmosphere as we produce. 

Growth in the amount of energy generated from offshore wind is a key part of achieving Net Zero and the Government’s Energy White Paper sets an ambitious target to deliver 40 GW of offshore wind connected to the network by 2030 – enough to power every home in the UK. National Grid will play a vital role, ensuring that the high-voltage network can carry this cleaner, greener energy across the country to where it is needed.

Growth in offshore wind also offers significant opportunities for economic growth and job creation. There are up to 60,000 jobs expected to be created in the offshore wind sector alone in this decade, and up to 250,000 jobs by 2030 across the proposals in the Government's ‘Ten Point Plan for a Green Industrial Revolution.

The Climate Change Committee anticipate the demand for low-carbon electricity will at least double by 2050 from 2019 levels as we shift to clean energy to drive electric vehicles, heat our homes and power our industry.

The Committee’s Sixth Carbon Budget published in December 2020 recommends deploying 40 GW of offshore wind by 2030, rising to maybe as much as 140 GW of offshore wind by 2050.

By 2050, our own analysis indicates that the energy sector needs to fill around 400,000 jobs to build the Net zero energy workforce.

Our mission at National Grid is to support these aims. We believe by acting now, the UK can become the world’s first major clean economy, with net zero carbon emissions by 2050, creating growth and jobs for communities across Great Britain.

How is the need for electricity network reinforcement identified?

The System Operator, National Grid ESO, leads an annual process looking at how the electricity transmission network might need to adapt to likely changes to where the electricity we all use will come from. That starts with stakeholder discussions and analysis about potential Future Energy Scenarios which are published each summer. The System Operator takes those different scenarios and looks at what that might mean for the transmission network over the next ten years, publishing an Electricity Ten Year Statement each November. The transmission network owners, including National Grid Electricity Transmission, respond to the issues outlined in the Electricity Ten Year Statement with suggestions as to how those can be addressed. Then in January each year, National Grid ESO publishes a document known as the Network Options Assessment (NOA), which outlines their recommendations as to which reinforcement projects should be taken forward during the coming year to meet the future network requirements.

Where is the need to reinforce this part of the network between Bramford to Twinstead explained?

This part of the network is currently a bottleneck which limits the capability of the network to carry more electricity out of East Anglia. National Grid ESO outlined in the 2020/21 Network Options Assessment (p43) that the reinforcement between Bramford and Twinstead is critical in all future energy scenarios. The System Operator reconfirmed this in the latest NOA 2021/22 (p22).

When will the 2021/22 Network Options Assessment (NOA) be published?

The 2021/22 NOA was published on 31 January 2022.

Has there been a change in the amount of generation contracted to connect in East Anglia?

There has been no change in the total amount of electricity generation contracted to connect to the transmission network in the region (just under 24.5 GW) since non-statutory consultation.  One offshore wind farm (Five Estuaries) is now contracted to connect in 2030 rather than 2029.

If there are any further changes to the timing or phasing of generation projects contracted to connect to the electricity transmission network after the statutory consultation, we will review any such changes, consider the impacts on our proposals and include further details in the application for Development Consent.

Is there a direct correlation between increasing population in an area and demand, particularly as the forecast was showing a potential decrease in demand?

Electricity demand in the eastern region is forecast to decline slightly in the middle of this decade due to increased efficiency in how electricity is used (e.g. through smart metering and energy efficient appliances). By the end of the decade however, demand is forecast to be back around present levels. Beyond this decade, electricity usage is forecast to increase significantly due to increasing use of electricity for transport and heating.

Can National Grid provide further details on the predicted demand for electricity in the area for the next 5 – 10 years, particularly given the forecast in increased use of electric vehicles?

You can find the forecast demand for East Anglia each year up until 2030 in the table below:

Year2021202220232024202520262027202820292030
Forecast demand (MW)1,3461,3031,2871,2801,2871,2981,3121,3511,3871,413
If Sizewell C experiences further delays, will this mean that reinforcement at Bramford to Twinstead is no longer needed?

No, there are a number of electricity generators looking to connect in East Anglia over the next decade. These include new interconnectors such as Eurolink and Nautilus, offshore wind farms such as Hornsea Project 3 and North Falls and Five Estuaries. Even if Sizewell experiences any further delays, the reinforcement between Bramford to Twinstead would still be needed.

What else is being done to improve the capability of the electricity transmission network, before new reinforcements are needed?

Before building any new electricity lines, we look first and foremost at whether we can deliver more capability by upgrading the existing network.

We have already upgraded the existing 400kV lines between Bramford and Twinstead to carry more electricity and will continue this work on the transmission network to Rayleigh. We will also be upgrading the lines between Pelham and Twinstead and Twinstead to Tilbury via Braintree and Rayleigh, and between Norwich and Bramford.

We will also be increasing the voltage of the electricity line running from Waltham Cross south into London to carry more electricity into the capital by that route. In addition, we will be installing new power control devices at Burwell, Pelham and Rye House to move more electricity to where it’s needed via that route.

These improvements will increase the transfer capability of the transmission network here in East Anglia from 3.5 GW to just under 6 GW, but that still doesn’t deliver the network capability that is needed in the region by the end of this decade.

Could alternatives – including offshore cables - take away the need for the Bramford to Twinstead reinforcement?

The System Operator, National Grid ESO, has explained that the Bramford to Twinstead reinforcement is critical in all future energy scenarios. This was set out in the Network Options Assessment (NOA) 2020/21 (p43) and is reconfirmed in the latest NOA 2021/22 (p22). In addition to Bramford to Twinstead there are also other reinforcements planned to increase the overall capacity of the network in East Anglia, this includes offshore cables between East Anglia and Kent.

The System Operator has also noted that the viable offshore options under the ‘Leading the Way’ scenario do not displace any existing onshore NOA recommendations (NOA 2020/21 p69)including the need for onshore reinforcements including Bramford to Twinstead, which needs to be in place by 2028. The reinforcement between Bramford and Twinstead is designed to address a bottleneck on the network, which has to be addressed. This position is expected to remain unchanged in the 2021/2022 NOA, which the System Operator is looking to refresh in June 2022 when their work to look at a Holistic Network Design is complete.

Could the work that the System Operator is doing to produce a Holistic Network Design change the need for the reinforcement?

The Network Options Assessment (NOA) 2021/22 (p22) reconfirms that Bramford to Twinstead is critical in all future energy scenarios.  The System Operator also explains in NOA 2021/22 (p5), that the need for critical reinforcements such as this is likely to be reinforced by the Holistic Network Design (HND). A refreshed NOA is expected to be published by the System Operator in June 2022 alongside publication of the HND.

Does National Grid plan on using superconductors, a technology that may reduce adverse visual impacts of the scheme?

When considering a reinforcement, we look at all the technologies available to us and assess them on their merits, including cost, power capability and environmental impact.

We are committed to innovation and have deployed some world leading technologies such as ‘Smart Wires’, the Albany superconductor scheme, and high voltage direct current (HVDC) projects and view innovation as a key requirement in delivering the network needed in the future.

At the present time, superconducting technology is in its infancy and has only been trialled in a small number of circumstances globally. Superconducting technology is not yet at a level where it can provide the capacity, voltage level or distance required by the Bramford to Twinstead reinforcement. While we are monitoring how this technology develops in the future and will continue to install innovative technology where proven and appropriate, for the moment it is not a technology that could be considered for any major transmission project.

Overhead lines remain a viable technology and are likely to be the appropriate option for many projects for the foreseeable future due to their capacity and costs, as well as being the ‘strong starting presumption’ in government policy.

Have National Grid considered AC High Temperature Superconductors (HTS)?

High temperature superconductors are named due to their ability to demonstrate superconducting properties at temperatures above Absolute Zero Kelvin. However, they operate at a temperature of circa -140oC and require cooling by liquid nitrogen. At present the power carrying capacity available using this technology is relatively low. AC High Temperature Superconductors are currently being used to provide power transfer over short distances in urban constrained environments. They are operating at voltages well below 400kV and the highest rated scheme, in Munich, provides 500MW of power capacity, which is 13.5 times smaller than the capacity required for the Bramford to Twinstead reinforcement. The limited capacity of AC High Temperature Superconductor technology makes it currently unviable for major transmission projects such as Bramford to Twinstead.

Bramford to Twinstead

What is the Bramford to Twinstead reinforcement?

The Bramford to Twinstead reinforcement is a new 400,000 volt (400kV) electricity double circuit between Bramford substation, west of Ipswich in Suffolk and Twinstead, south of Sudbury in Essex. 

The route is shown on the overview map below, but for more information, please see the detailed mapping on the 'Our proposals' page.

Overview map of the Bramford to Twinstead Reinforcement proposals
Why did National Grid put the reinforcement on hold?

Between 2009 and 2013 work was previously undertaken to develop proposals to add this much needed network capability between Bramford and Twinstead Tee. Several rounds of extensive consultation were undertaken, and many meetings held with community representatives, council officers and environmental bodies. Changes back then to when planned new generation would come online in East Anglia, in particular Sizewell C, meant that work was put on hold at the end of 2013.

Did the consultation responses from 2009-2013 have any impact on the proposals?

Yes, feedback from stakeholders and the local community was a key influence on the development of major aspects of our proposals including:

  • the selection of route corridor 2
  • the proposed removal of 25 km of existing UK Power Networks 132 kV overhead line
  • the identification of two areas, making up around a quarter of the route (approximately 8 km), where the high cost of putting cables underground was considered justifiable for the proposed 400 kV line – through Dedham Vale Area of Outstanding Natural Beauty (AONB) and parts of the Stour Valley
  • the identification of a suitable location for a new grid supply point substation west of Twinstead and south of Sudbury, to keep the local area supplied with electricity once the 132 kV is removed
How has National Grid responded to feedback from the consultation in March 2021?

The feedback received from our non-statutory consultation in spring 2021 has helped to shape and guide the development of the reinforcement. As a result of feedback, we have made some changes to our plans. These are all detailed in the project background document, but in summary between non-statutory and statutory consultation we are:

  • confirming undergrounding in two sections of the draft alignment in and near to the Dedham Vale AONB and parts of the Stour Valley
  • proposing a greater amount of undergrounding overall
  • changing the route and configuration of pylons around Bramford Substation
  • considering a potential option for routeing the overhead line at Hintlesham Woods
  • proposing an alternative route of undergrounding in the Dedham Vale AONB at Dollops Wood, resulting in the reduction of transmission lines in the AONB by around 1km
  • proposing an alternative route of undergrounding in the Stour Valley
  • proposing new sites for three of the proposed cable sealing end compounds
  • proposing to remove more of the existing 400 kV overhead line running south from Twinstead Tee and the diamond crossing
  • proposing to build more full tension gantries at cable sealing end compounds to reduce the overall number of terminal pylons along the route
What will Bramford to Twinstead include today?

The reinforcement would comprise approximately 19km of overhead line (consisting of 55 new pylons and conductors) and 10km of underground cable system (consisting of 20 cables with associated joint bays and above ground link pillars).

Four cable sealing end (CSE) compounds would be required to facilitate the transition between the overhead and underground cable technology. Each CSE would be within a fenced compound, and contain electrical equipment, support structures, a small control building and a permanent access track.

It is proposed that approximately 27.5 km of existing overhead line and associated pylons would be removed as part of the proposals (approximately 25km of existing 132kV overhead line between Burstall Bridge and Twinstead Tee, and approximately 2.5km of the existing 400kV overhead line to the south of Twinstead Tee). To facilitate the overhead line removal, a new grid supply point (GSP) substation is required at Butler’s Wood, east of Wickham St Paul, in Essex. The GSP substation would include associated works, including a small single circuit CSE compound, replacement pylons and underground cables to tie the substation into the existing 400 kV and 132 kV networks.

Other ancillary activities would be required to facilitate construction and operation of the reinforcement, including (but not limited to): 

  • modifications to, and realignment of sections of the existing 400 kV overhead line
  • temporary land use to facilitate construction activities including working areas for construction equipment and machinery, site offices, welfare, storage and access
  • temporary infrastructure to facilitate construction activities such as amendments to the highway including bellmouths for site access, pylons and overhead line diversions, scaffolding to safeguard existing crossings, watercourse crossings and diversions of Public Rights of Way
  • diversion of third-party assets and land drainage from the construction and operational footprint
  • land for mitigation, compensation and enhancement of the environment as a result of the environmental assessment process, and National Grid’s commitments to Biodiversity Net Gain
How have you listened to local people when designing this reinforcement?

Feedback from our non-statutory consultation in 2021 has very much shaped our proposals.  You can read more about that in the ‘You said, We did’ table, which can be found in our Non-statutory consultation report, available from our Document library.

Why is it needed?

Reinforcing this part of the network is needed between Bramford and Twinstead to resolve a bottleneck in the network. At the moment there are three double circuit overhead lines carrying the electricity generated elsewhere into Bramford (one from Norwich to the north and two from Sizewell to the east), but only one overhead line carrying power west of Bramford out of the region.

With substantial new sources of electricity connecting in the region by the end of the decade, the existing overhead line carrying circuits west from Bramford to Pelham and from Bramford to Braintree/Rayleigh/Tilbury, would be overloaded.

Installing a new line (two circuits) between Bramford and Twinstead, allows the network to be reconfigured to create two separate double circuit routes that will avoid overloading the existing circuits and will provide flexibility and agility in the way the network interacts.

Why not reinforce Bramford in other directions? Have you considered other options for Bramford to Twinstead?

The line running west from Bramford to Twinstead is the main bottleneck on the network and without reinforcing this part of the network the ability to transport power out of the region will be significantly constrained.

We have checked again to see whether there may be a more appropriate strategic option to address the network bottleneck between Bramford and Twinstead. You can read more about our review in the latest Project Development Options Report, available in our Document library.

23 strategic options in and around Bramford that might achieve the required reinforcement have been examined, including the original options considered in 2009. These included:

  • doing no physical works;
  • re-directing proposed connections;
  • maximising existing connections;
  • reinforcing north of Bramford with new 400 kV network infrastructure;
  • reinforcing south of Bramford with new 400 kV network infrastructure;
  • bypassing Bramford with new 400 kV network infrastructure; and
  • reinforcing west of Bramford with new 400 kV network infrastructure.

Those that would not fully address the constraint or meet the Security of Supply Standard were discounted. We also discounted others that would not offer some material benefit over another option, for example, more expensive options which would provide the same network capacity.

Why was this route option chosen?

In 2009, we presented four route corridor options for consultation. After carefully considering all the feedback received and taking into account findings from environmental and technical surveys, we selected Corridor 2 as the preferred corridor. We then looked at different alignments within the corridor, as set out within our Connection Options Report (available in the 'Archive consultation documents' section of our Document library) in 2012 before selecting the current route alignment.

Corridor 2 was chosen because it would represent the least scale of change to the existing environment, as it allows the new route to largely parallel the existing 400 kV overhead line, and to replace the existing 132 kV overhead line which is to be removed.  In the sections of the route where the 132 kV overhead line is being replaced by new 400 kV overhead line, the route of the existing line is being followed where practicable.

We have reviewed the historic work undertaken between 2009 and 2013 prior to the non-statutory consultation in spring 2021. After carefully considering our statutory duties and obligations to be efficient, coordinated and economical, and to have regard to the desirability of preserving amenity, reinforcing the network between Bramford and Twinstead was identified as the most suitable option. Further details, including the reasons why alternatives were taken forward or discounted, can be found in our Project Development Options Report, available in our Document library.

Why can’t you put the new 400 kV line to the south of Hintlesham, where the current 132 kV runs?

Prior to the project being put on pause in 2013, we considered four route corridors between the connection points at Bramford Substation and Twinstead Tee. Following consultation, a decision was reached to progress with Corridor 2 which proposed the removal of the existing 132kV overhead line between Burstall Bridge and Twinstead Tee and the adoption of its route for a new 400kV overhead line.

Although Corridor 2 was progressed, further work was undertaken to look in more detail at the eastern portion of the route corridor around Hintlesham, where Corridor 2 was split into Corridor 2A and 2B. Corridor 2A followed the 132kV line to the south of Hintlesham; and Corridor 2B paralleled the existing 400kV line to the north of Hintlesham rather than following the 132kV line.

Following further work, it was concluded that Corridor 2B to the north of Hintlesham was preferred over Corridor 2A. This is because Corridor 2A would result in a new overhead line to the north of Burstall Bridge, where there is currently no overhead line. It would also result in an overhead line to the south of Hintlesham with no overhead line to parallel leading to greater landscape and visual effects than Corridor 2B. In addition, Corridor 2B would result in a minor positive effect on Corridor 2A, as it would allow approximately 4km of the existing 132kV overhead line to be removed and not replaced, which would benefit landscape and views and the setting of listed buildings to the south of Hintlesham.

To read more about this decision, please see our Project Development Options Report, available in our Document library.

Why can’t you place Bramford to Twinstead entirely underground?

We are required under the Electricity Act 1989, to find a balance, developing proposals that are efficient, coordinated and economical, and which have regard to people and places. Each network upgrade must be considered on its individual merits, as required in planning law.

The national policy statement (NPS) which covers building electricity networks infrastructure (EN-5) states that the government expects overhead lines will often be appropriate. It does, however, recognise that there will be cases where this is not so, for example, at particularly sensitive locations, where potential adverse landscape and visual impacts of an overhead line may make it unacceptable in planning terms, taking account of the specific local environment and context.   

National Grid’s duties and obligations include balancing the need to be economic and efficient, which includes keeping costs down in the interests of the bill-paying consumers, with a duty to have regard to preserving amenity, which includes the natural environment, cultural heritage, landscape and visual quality.  

Our proposals include underground cable within the Dedham Vale AONB, and an area of the Stour Valley. 

What is the additional cost of undergrounding the lines?

We are required under the Electricity Act 1989, to find a balance, developing proposals that are efficient, coordinated and economical, and which have regard to people and places. Each network upgrade must be considered on its individual merits, as required in planning policy.

The national policy statement (NPS) which covers building electricity networks infrastructure (EN-5) states that the Government expect that fulfilling this need through the development of overhead lines will often be appropriate.  It does, however, recognise that that there will be cases where this is not so, for example, at particularly sensitive locations, where potential adverse landscape and visual impacts of an overhead line maymake it unacceptable in planning terms, taking account of the specific local environment and context.

The costs for different options are provided in the table below. It should be noted that market and material costs have changed since 2013 and are likely to do so again before we reach construction, but based on analysis undertaken 2021, the capital cost estimates rounded to the nearest £m, are provided and continue to offer a basis for comparative assessment.

These figures were prepared to support the non-statutory consultation, further information is available in the Project Development Options Report (2021) available in our document library.

OptionDescription2021 capital cost
Proposed option (predominantly overhead line with underground cables in Dedham Vale AONB and Stour Valley)Substations, overhead line, 2 x underground cable sections in Dedham Vale AONB and Stour Valley, 4 x cable sealing end compounds£363m
Predominantly overhead line with underground cables in Dedham Vale AONB onlyAs proposed option, apart from overhead line in Stour Valley instead of underground cable and 2 x cable sealing end compounds£245m
Predominantly overhead line with underground cables in Stour Valley onlyAs proposed option, apart from overhead line in Dedham Vale AONB instead of underground cable and 2 x cable sealing end compounds£256m
Entirely overhead lineSubstations, overhead line for whole route£142m
Entirely underground cableSubstations, underground cable for whole route£694m
Will you be undergrounding in the Stour Valley?

Following feedback from key stakeholders during the 2021 non-statutory consultation, we can confirm our intention to underground 4km of new 400kV transmission line through the most highly valued parts of the Stour Valley. In addition, as part of the Bramford to Twinstead reinforcement approximately 5km of existing 132kV overhead line and 2.5km of existing 400kV overhead line will be removed from the Stour Valley Project Area, meaning there will be fewer overhead lines in this landscape when the work is complete.

What is the cost of undergrounding between Dedham Vale and Stour Valley?

We are required under the Electricity Act 1989, to find a balance, developing proposals that are efficient, coordinated and economical, and which have regard to people and places. Each network upgrade must be considered on its individual merits, as required in planning policy.

The national policy statement (NPS) which covers building electricity networks infrastructure (EN-5) states that the Government expect that fulfilling this need through the development of overhead lines will often be appropriate.  It does, however, recognise that that there will be cases where this is not so, for example, at particularly sensitive locations, where potential adverse landscape and visual impacts of an overhead line maymake it unacceptable in planning terms, taking account of the specific local environment and context.

The costs for different options are provided in the table below. It should be noted that market and material costs have changed since 2013 and are likely to do so again before we reach construction, but based on analysis undertaken 2021, the capital cost estimates rounded to the nearest £m, are provided and continue to offer a basis for comparative assessment.

These figures were prepared to support the non-statutory consultation, further information is available in the Project Development Options Report (2021) available in our document library.

OptionDescription2021 capital cost
Proposed option (predominantly overhead line with underground cables in Dedham Vale AONB and Stour Valley)Substations, overhead line, 2 x underground cable sections in Dedham Vale AONB and Stour Valley, 4 x cable sealing end compounds£363m
Predominantly overhead line with underground cables in Dedham Vale AONB onlyAs proposed option, apart from overhead line in Stour Valley instead of underground cable and 2 x cable sealing end compounds£245m
Predominantly overhead line with underground cables in Stour Valley onlyAs proposed option, apart from overhead line in Dedham Vale AONB instead of underground cable and 2 x cable sealing end compounds£256m
Entirely overhead lineSubstations, overhead line for whole route£142m
Entirely underground cableSubstations, underground cable for whole route£694m
Can the section of line in Leavenheath and Assington be undergrounded?

The extent of undergrounding is proposed following careful consideration of the feedback received during earlier consultations, the alternatives available and other factors which need to be considered, including our duties and obligations. That includes balancing the need to be economic and efficient and a duty to have regard to preserving amenity, which includes the natural environment, cultural heritage, landscape and visual quality.

Following feedback at the non-statutory consultation, we have undertaken a back check and review of the proposed extent of undergrounding in Section F, taking account of our statutory duties and other obligations.

We concluded that Section F is not within a designated landscape and the proposed 400kV overhead line would parallel the existing 400kV overhead line, whilst the existing 132kV overhead line would be removed. The proposals would therefore leave the same number of overhead lines in the landscape. The proposed 400kV overhead line would be taller than the existing; however this would result in a low magnitude of change from how the area looks today.

We have concluded that, when taking into account all of our duties and the baseline environment in this section, overhead lines should remain the preferred approach. It is considered that the current proposals strike an appropriate balance.

Is National Grid proposing to underground more of the line than proposed at non-statutory consultation?

National Grid can confirm that we are proposing to underground two sections of the line, in the Dedham Vale AONB and parts of the Stour Valley.

At non-statutory consultation we proposed around 8km of underground cables, this has now increased to approximately 10 km.

What is horizontal directional drilling?

Horizontal directional drilling (HDD) is a method of installing underground pipelines and cables through trenchless methods. It involves the use of a directional drilling machine to accurately drill along the chosen bore path and install the required cable without impacting above ground features.

Why can horizontal directional drilling not be used for the entirety of the underground route?

Horizontal directional drilling (HDD) has distance limitations and as depth of installation increases, the cables need to spaced wider apart to allow heat to dissipate. 

What if people are willing to pay extra to put proposed new overhead lines underground?

The extent to which the bill-paying public should pay for the additional cost for undergrounding cables is a decision for the government, not National Grid. When looking at the costs of a new reinforcement, National Grid is guided by the laws, policies and regulations that have been set by the government on behalf of electricity consumers. We are required through those to balance affordability to the electricity bill-payer with the impact of our proposals on other factors, including the environment.

 

Who owns the smaller 132 kV overhead line, is it used and will it stay?

The 132 kV overhead line is owned and operated by the Distribution Network Operator, UK Power Networks (UKPN).  As part of this reinforcement, National Grid has agreed with UKPN that it will remove the 132 kV overhead line between Burstall Bridge and the diamond crossing near Twinstead Tee.  The removal of the 132kV overhead line will allow the new 400 kV overhead line to be aligned along this route for the most part. To the south of Hintlesham, the 132 kV overhead line will be removed from the landscape as it is no longer required, as the new 400 kV overhead line will parallel the existing 400 kV overhead line from Bramford Substation to Hintlesham Woods.

Why can’t the 132 kV overhead line west of the diamond crossing also be removed?

The stretch of existing 132 kV overhead line between the diamond crossing and the grid supply point substation is not owned or controlled by National Grid. It is owned and operated by UK Power Networks (UKPN). The removal of this section of overhead line is not required in engineering terms for the route of the new 400kV overhead lineDiscussions with UKPN are ongoing, and we will have regard to consultation feedback regarding the existing distribution network.

Will the reinforcement or the new substation at Butler’s Wood mean more solar farms will be developed in the area?

The new grid supply point substation at Butler’s Wood would be designed solely to provide supplies to the local UK Power Networks distribution network. Should any separate applications be brought forward by developers in the future, be these for solar farms or anything else, these would be considered on their own merit by the appropriate determining authority. 

Why are you not proposing to go offshore or subsea rather than developing overhead lines?

Prior to our consultation last year, we checked again to see whether there may be more appropriate strategic options to address the network bottleneck between Bramford and Twinstead.

To summarise, 23 strategic options that might achieve the required reinforcement were examined, including offshore and subsea options. Those options would not fully address the constraint or enable the network to operate to the required standards. More information on this is available in the Project Development Options Report (March 2021), available in our Document library.

We are already proposing an offshore reinforcement (SEA Link) along with other additional electricity lines, and these reinforcements alone do not deliver the additional capacity required to resolve the specific bottleneck in the network between Bramford and Twinstead.

How tall will the proposed pylons be?

We are proposing using standard steel lattice pylons which are approximately 50 m in height. Taller pylons may be required in some locations depending on the local topography and also to avoid sensitive features.

 

How many pylons are you proposing throughout the whole route?

At this stage in the design there would be approximately 55 new pylons. However, we will be removing approximately 27.5 km of existing 132 kV and 400 kV overhead lines from the same stretch of route.

Why are you proposing to use lattice pylons, why not T-pylons which are smaller and less intrusive on the landscape?

National Grid has looked at alternative designs for the pylons.

Alternative designs include the new mono-pole ‘T-pylon’ which is being used on the Hinkley Connection Project, and lower-height lattice pylons, which are bulkier versions of the regular lattice designs. 

As the new pylons would run alongside the existing 400 kV overhead line, using a similar style lattice pylon  would be preferable to introducing a new design into the landscape.  

Can I see the exact locations for where all of the pylons will be?

We are only showing indicative locations for the new pylons. This is very common for long linear infrastructure projects, as we are seeking approval for the infrastructure contained within our draft Order Limits (shown in red on our consultation plans). These limits form the boundary of the area in which the reinforcement could take place.

Guidelines called Limits of Deviation (LoD) lie within the draft Order Limits, and they provide the necessary flexibility when constructing the authorised development, reducing the risk that the reinforcement as approved cannot later be implemented for unforeseen engineering or geological reasons. For example, previously unidentified poor ground conditions may require a pylon to be moved for geotechnical reasons, such as ground stability. The LoD set specific parameters to moving infrastructure on the ground, as well as establishing the maximum vertical height of the infrastructure.

You can see the indicative locations of pylons in our Typical Design and Layout Plans, available in our Document library. We have also produced a guide on how to interact with our plans to assist when viewing our drawings.

 

What are cable sealing end compounds?

Cable sealing end compounds are where high-voltage underground cables join onto an overhead line, the transition from one to the other requires termination points, known as sealing end compounds.

The Network Options Assessment identifies a number of other reinforcements in the area, what is happening with those routes?

Further reinforcements have been identified including East Anglia GREEN (ATNC and AENC in NOA). Work is underway to identify where this infrastructure may be routed, and further information will be available at a consultation later this year.

As part of the Environmental Impact Assessment for Bramford to Twinstead we will be considering cumulative impacts which will take into consideration how future plans interact with the Bramford to Twinstead reinforcement as and when information is made available.

Has National Grid considered battery storage to allow energy to be stored when not needed?

Although battery storage is important, National Grid still needs to be able to transport that energy to where it will be consumed.

How many transformers would be required for the grid supply point substation at Butlers Wood?

Following discussions with UKPN, it has been confirmed that National Grid needs two transformers.

The substation would transform electricity from National Grid’s 400kV line down to 132kV as needed by UKPN’s network.

Can National Grid provide artist impressions of how the new equipment will look?

As part of the consultation we are showing a number of illustrations of equipment including cable sealing end compounds and the grid supply point substation. In addition, we have also prepared a photomontage document which shows how the reinforcement will look once complete from a handful of locations across the route. These plans are available in our Document library.

How regularly will the underground cables, overhead lines and grid supply point need maintaining?

It is anticipated that maintenance will be infrequent and localised causing limited disturbance.

Why are you presenting two options around Hintlesham Woods?

During the 2021 non-statutory consultation, and during subsequent discussions with members of the public and local landowners, concerns were raised regarding the potential landscape and visual effects of the draft alignment to the north and west of Ramsey Wood and the impact it would have on local properties. Preference has been expressed for a parallel alignment to the existing 400kV overhead line through Hintlesham Woods. Further information is provided within the Project Development Options Report, available in our Document library.

Because of this feedback, we are presenting two options during the statutory consultation in order to seek further feedback before deciding which option to take forward.

  • Hintlesham Woods Option 1 (presented at the 2021 non-statutory consultation): The existing 400kV overhead line would be diverted on new pylons to the north and west of the woodland. The proposed 400kV overhead line would use the existing pylons through the woodland.
  • Hintlesham Woods Option 2: The existing 400kV overhead line would remain in situ. The proposed 400kV overhead line would be constructed parallel to the existing overhead line to the south on new pylons located outside of the woodland.

The draft order limits include the combined order limits of both options so that either option could be taken forward.

This feedback will be used, along with further engineering and environmental assessment, to identify the preferred option which will be presented as part of the application for development consent.

Why are you submitting a separate planning application for the grid supply point (GSP) substation?

We need to build the Bramford to Twinstead reinforcement to support the government’s ambition to see 40 GW of offshore wind connected by the end of this next decade.

The first stage of the reinforcement  will be to build the GSP substation – we need it in place before we can take down the existing line of 132 kV pylons owned by UK Power Networks. This may allow us to remove the 132 kV overhead line sooner. And, in turn, we need to remove some of these pylons to give us the space to build the new 400kV reinforcement.

To support the programming for the construction, we plan to submit a planning application for the GSP substation this year, ahead of the application for development consent for the reinforcement in winter 2022/23.

 

How can I give my views on the grid supply point (GSP) substation/when will you consult on the GSP substation?

We are seeking comments and views on the GSP substation as part of the current statutory consultation. Any comments received during the statutory consultation will be used to inform both the application for development consent and the proposed planning application for the GSP substation under the Town and Country Planning Act.

When will the substation be operational?

Bramford substation is already operational - supplying the local area and connecting existing generation to the electricity transmission network.

It is likely that the grid supply point substation at Butler’s Wood would become operational between 2025 and 2026, depending on the outcomes of the planning process.

What is the operational life of the substation?

We expect the operational life of the GSP substation to be at least 40 years.

How long will the new pylons last?

The pylons are designed to have a minimum lifespan of 40 years, subject to annual inspection. Refurbishment could extend the lifespan of pylons. 

What is the voltage and the maximum power that the proposed cables are designed to carry?

The proposed reinforcement is 400 kV and the underground cables are designed to carry maximum winter power flows of 2580 MVA (pre-fault) and 3326MVA (post-fault) per circuit. MVA = Megavolt amperes.

East Anglia GREEN (ATNC and AENC in NOA)

Is the proposed reinforcement between Norwich and Bramford for a new line or upgrading the existing line?

The requirement, as identified in the Network Options Assessment 2020/21, is for a new line.

What is happening with ATNC and AENC?

East Anglia GREEN (ATNC and AENC) has been identified by National Grid ESO as being one of a number of reinforcements needed on the east side of the country to deliver 40 GW of offshore wind by 2030. 

Work is underway to identify where this infrastructure may be routed, and further information will be available at a consultation later this year.

Will East Anglia GREEN (ATNC) follow the route of the existing overhead lines (to make a third overhead line between Bramford and Twinstead)?

We are still carrying out routeing and siting assessments for East Anglia GREEN. However, the ongoing optioneering work does not currently indicate a tripling of the Bramford to Twinstead route.

How will cumulative impacts be considered?

The Environmental Impact Assessment (EIA) for the Bramford to Twinstead reinforcement will include a cumulative effects assessment , which will consider the cumulative effects between the Bramford to Twinstead reinforcement and other proposed developments. The cumulative effects assessment will be presented as part of the Environmental Statement (ES).

The cumulative effects assessment will be undertaken based on information available on other developments at the time of assessment.

Further information on how we have established which developments to include within the cumulative effects assessment can be found in the Preliminary Environmental Information Report, available in our Document library.

 

Government policy

Why are we not building an offshore ring main or waiting for the outcome of the Offshore Transmission Network Review?

We welcome the government’s Offshore Transmission Network Review, which seeks to address these challenges.

The government has shown a clear commitment to developing further offshore wind at scale. The Energy White Paper in December 2020 sets a target to deploy 40 GW of offshore wind by 2030 – enough to power every home.

The Bramford to Twinstead reinforcement is required to resolve a critical bottleneck on the onshore network to support power exporting from East Anglia and ensure we can continue to operate a safe, compliant and economic transmission network. This means the reinforcement is required regardless of offshore co-ordination, as there will still be a significant increase in the levels of power being brought onshore as we move towards the government’s ambition of connecting 40GW of offshore wind by 2030.

Why is National Grid not waiting for the government’s conclusion on the Offshore Transmission Network Review (OTNR) before proceeding with the reinforcement?

National Grid welcome the review and have been working with BEIS throughout this time.

The Bramford to Twinstead reinforcement needs to be in place by 2028 to carry cleaner, greener energy to homes and businesses, which will help meet the government’s net zero and offshore wind targets.

The Electricity System Operator has explained that viable offshore options under the ‘Leading the Way’ scenario do not displace the need for onshore reinforcement including Bramford to Twinstead  (Network Options Assessment [NOA] 2020/21, p69). The reinforcement between Bramford and Twinstead is designed to address a bottleneck on the network which needs to be addressed. This position is expected to remain unchanged in the 2021/2022 NOA. Should the OTNR produce any outputs which cause us to reflect on the reinforcement options we are taking forward, then of course we would need to do that.

Community

What benefits will Bramford to Twinstead bring to the community?

We know that our responsibility as a business goes beyond safely building new energy infrastructure to enable a cleaner, fairer and affordable future.  We want to leave a lasting positive impact where we build our projects to help those areas and communities thrive and to support a sustainable future.

There are four key areas where we believe we can bring benefit to local communities and stakeholder groups who are hosting the infrastructure that supports the green energy transition:

  • Natural Environment – we will build partnerships with environmental groups and NGOs where we can support initiatives that enhance the landscape, biodiversity and availability of green space within the areas we are constructing our projects.
  • Net Zero – we will work collaboratively with local authorities and partner organisations to offer our expertise and support in delivering the net zero priorities for that region.
  • Skills and employment – we will extend our Grid for Good programme to deliver training and skills development in the region that will ultimately deliver employment opportunities in the net zero industry.  In addition to this, we will work with our suppliers to develop opportunities for local employment and to bring benefit to the local economy through our projects. We also work with schools and local authorities to encourage the next generation of engineers and help the long term unemployed develop new skills.
  • Community Grant Programme - through our Community Grant Programme, charities and not- for- profit organisations can apply for a grant towards community-based initiatives that deliver social, economic and environmental benefits.

We hope, therefore, that both the offshore and onshore development needed to support the transition to a cleaner, greener future, can deliver sustainable, green growth and an economic ‘ripple effect’ that will continue for years.

Will the construction and the running of the substation bring any new jobs to the area?

Whilst our substations are generally operated remotely and require maintenance rather than operational personnel routinely on site, our Bramford substation is a local operational team base location.

During construction, we will work with our suppliers to develop opportunities for local employment and to bring benefit to the local economy through our projects. There are also huge opportunities in the renewable energy sector that our proposals support.

As the government explain in the Energy White Paper, fighting climate change offers huge opportunity for growth and job creation. The global markets for low-carbon technologies, electric vehicles and clean energy are fast growing. The government estimates zero emission vehicles could support 40,000 jobs by 2030 and 40 GW of offshore wind in the same period will support up to 60,000 jobs. Altogether the Government Ten Point Plan sets out a vision that will support up to 250,000 jobs by 2030 and see every home in the country powered by offshore wind. Our own analysis in our ‘Job That Can’t Wait’ report, shows that the country needs to fill 400,000 jobs in the energy sector in the next three decades to deliver net zero by 2050.

At National Grid we are investing around £1.3 billion every year, wiring up our communities to the next generation clean electricity network, so that every household can be powered by renewable energy by 2030. Where we are delivering those network investments, aside from opportunities for local suppliers, we work with schools and local authorities to encourage the next generation of engineers and help the long term unemployed develop new skills.

Will any of the electricity transported through this line be used to service the local area?

Yes, the Bramford to Twinstead connection is essential to support the growth in clean green energy from North Sea offshore wind. We will all benefit from that clean green energy and some will be consumed in East Anglia.

Has National Grid considered the effects on Suffolk’s tourism industry?

National Grid included an assessment on socio-economics, recreation and tourism within the 2021 Scoping Report. This concluded that the project was unlikely to have a significant effect on socio-economics and tourism and that it would be scoped out of the assessment as a standalone topic. The Planning Inspectorate agreed with this conclusion in their Scoping Opinion. Tourism will be considered, where applicable within the cumulative effects assessment. Further details can be found in the Preliminary Environmental Information Report, available in our Document library.

 

Will National Grid set up a community benefits agreement to compensate local communities?

We know that our responsibility as a business goes beyond safely building new energy infrastructure to enable a cleaner, fairer and affordable future.  We want to leave a lasting positive impact where we build our projects to help those areas and communities thrive and to support a sustainable future. 

There are four key areas where we believe we can bring benefit to local communities and stakeholder groups who are hosting the infrastructure that supports the green energy transition:

  • Natural Environment – we will build partnerships with environmental groups and NGOs where we can support initiatives that enhance the landscape, biodiversity and availability of green space within the areas we are constructing our projects.
  • Net Zero – we will work collaboratively with local authorities and partner organisations to offer our expertise and support in delivering the net zero priorities for that region.
  • Skills and employment – we will extend our Grid for Good programme to deliver training and skills development in the region that will ultimately deliver employment opportunities in the net zero industry.  In addition to this, we will work with our suppliers to develop opportunities for local employment and to bring benefit to the local economy through our projects. We also work with schools and local authorities to encourage the next generation of engineers and help the long term unemployed develop new skills.
  • Community Grant Programme - through our Community Grant Programme, charities and not- for- profit organisations can apply for a grant towards community-based initiatives that deliver social, economic and environmental benefits.

We hope, therefore, that both the offshore and onshore development needed to support the transition to a cleaner, greener future, can deliver sustainable, green growth and an economic ‘ripple effect’ that will continue for years.

Environmental impact

How will the Bramford to Twinstead reinforcement contribute to the Government’s 2050 Net Zero targets for a sustainable future?

As the UK looks to accelerate its economic recovery following the coronavirus pandemic, strategic infrastructure solutions such as those proposed along the east coast can help ensure that the UK continues to deliver strong, sustainable growth.

The Bramford to Twinstead reinforcement is one of the essential network reinforcements needed to deliver on the UK’s net zero target – without it, cleaner, greener energy generated offshore would not be able to be transported to homes and businesses across the country.

How will National Grid minimise the impact of the pylons on the environment and local ecology?

We are undertaking an Environmental Impact Assessment (EIA) for the reinforcement. This started back in 2009 and helped influence the routing and alignment studies. The EIA includes a number of baseline studies which tell us about the baseline environment within the area and this factors into our design and decision-making process, so that we seek to avoid and reduce impacts on the environment.

The EIA is ongoing and the results of the assessment will be presented within the Environmental Statement, submitted with the application for development consent. The preliminary results of the assessment can be found in the Preliminary Environmental Information Report published as part of the statutory consultation material.

We are consulting with the local and county councils in Suffolk and Essex, along with the Environment Agency, Natural England, Historic England, landowners and others. What these groups tell us and the feedback we receive through the consultations will help us to carefully plan our proposals and how we carry out the works. 

What is meant by biodiversity net gain?

The term biodiversity net gain means increasing the amount of biodiversity in an area than currently exists.

National Grid will value nature and will protect and enhance it where possible using ‘natural capital’ and ‘net gain’ principles. National Grid has made a commitment to deliver a 10% biodiversity net gain (BNG) on this reinforcement. This means that the habitat value for wildlife will be increased by around 10 per cent once the reinforcement is complete, compared to what currently exists. National Grid is working with appointed technical specialists, environmental organisations and landowners to identify potential opportunities for delivering environmental gains.

Has there been any investigation into the local wildlife that may be impacted by the construction?

We are carrying out environmental surveys, including habitat surveys and protected species surveys  and the results will help inform the design and decision-making process as we finalise our plans for the reinforcement.

There are a number of designated and non-designated sites within the draft Order Limits. These include the nationally designated Hintlesham Woods, which is a Site of Special Scientific Interest. It is designated for its ancient semi-natural woodland habitat and associated bird communities. There are also county and local wildlife sites.

We have identified some protected and priority species within and adjacent to the Order Limits. These  include  bats; badger; brown hare; dormouse; water vole; otter; reptiles; amphibians, including great crested newts; European eel and a range of bird species.

The Environmental Impact Assessment will consider any potential impacts to habitats and species and any measures required to mitigate or reduce the effects. The results of the assessment will be presented within the Environmental Statement, which will be submitted with the application for development consent. The preliminary results of the assessment can be found in the Preliminary Environmental Information Report published as part of the statutory consultation material.

 

Will further survey work take place before an application for development consent is submitted?

A suite of surveys were undertaken before the project was paused in 2013. We have started to update these surveys during 2021 to get an up to date understanding of the baseline environment. The baseline surveys will continue into 2022 and we will continue to engage with environmental organisations such as Natural England and the Environment Agency. The results of the surveys will be presented within the Environmental Statement, which will be submitted with the application for development consent. The preliminary results of the surveys to date can be found in the Preliminary Environmental Information Report, available in our Document library.

Can the route be diverted away from the Dedham Vale AONB?

In 2009, we presented four route corridor options for consultation, including two that routed the reinforcement away from the Dedham Vale AONB.

After carefully considering all the feedback received and taking into account findings from environmental and technical surveys, we selected the current route (Corridor 2) as our preferred option. This was seen as an opportunity corridor as it allowed for the removal and replacement of the existing 132 kV overhead line, to avoid the need for a third line. When we restarted work on the project, we carried out a thorough re-appraisal of the scope of the works and our decisions to date. Details on the corridor selection process can be found in the Project Development Options Report, available in our Document library.

We are proposing underground cables through the Dedham Vale AONB, and to take down the existing 132 kV line. This will result in one fewer line within the AONB than at present. We have also relocated the proposed site for the Dedham Vale East cable sealing end compound 1 km away from the boundary of the AONB to further reduce impacts on the setting of the AONB.

Will burying the cables have an adverse and disruptive impact on the local ecology?

Construction of underground cables creates disruption to an area of land while the cables are installed. In many cases, the land use would be reinstated after construction, such as replanting hedgerows and grass seeding. We have carefully considered the route of the underground cables to avoid sensitive areas, such as designated sites and sensitive habitats where practicable. Where this is not practicable, an assessment will be undertaken of the value of the habitat and suitable mitigation would be put in place where there could be significant effects to habitats or species. This may include creating new areas of habitat those lost.

What is ducting and how does that compare with other methods of installing underground cables?

The underground cables would be installed by open cutting a trench, within which the ducts would be laid. The trench surrounding the ducts would be filled with cement-based sand and a polymeric cable protection would cover the width of the trench. Topsoil and subsoil would be replaced over the top of the polymeric cable protection. The cables would then be pulled through the ducts.

 

A ducted system would result in a faster construction programme and would enable quicker reinstatement when compared to an open cut method, where the trench would remain open for the duration of the works

There may be locations where ducting is not the best solution, such as where topography limits installation techniques or where ground conditions could increase risk of damaging cable sheath. In such cases, standard open cut methods would be employed.

 

What will be the impact of the scheme on air quality?

There is likely to be some effects on air quality during construction due to the number of construction vehicles and equipment including generators. Dust may also be generated during construction, due to soil stripping and vehicles tracking on the haul routes. The good practice measures set out within the Outline Code of Construction Practice (an appendix to the Preliminary Environmental Information Report), such as turning off machinery when not in use and locating equipment away from sensitive features, would reduce the effects on air quality. With such measures in place, there are unlikely to be any significant effects on air quality during construction. Further details can be found within the Preliminary Environmental Information Report, available in our Document library.

How will noise and dust levels be monitored throughout construction?

The construction works have the potential to generate noise and dust from the construction vehicles and equipment. A noise and dust assessment will be prepared as part of the EIA and the results presented within the application documents submitted for development consent.

The Construction Environmental Management Plan will set out the monitoring that would be undertaken during construction. This will include regular inspections of the working area to check the good practice measures are being employed and to identify whether additional measures are required.

How will you protect the environment?

At the beginning of each reinforcement and as we plan the work, we carefully consider potential environmental effects to make sure that we avoid or reduce potential significant effects on the environment. We are consulting with the local and county councils in Suffolk and Essex, with the Environment Agency, Natural England, Historic England,  landowners and others. What these groups tell us and the feedback we receive through the consultations will help us to carefully plan our proposals and how we carry out the works.

Health

What are EMFs?

EMFs are electric and magnetic fields. Electric fields are produced by voltage and magnetic fields by current flowing through a conductor. Overhead lines are a source of two fields: the electric field (produced by the voltage) and the magnetic field (produced by the current). Underground cables eliminate the electric field altogether as it is screened out by the sheath around the cable, but they still produce magnetic fields.

Where do EMFs occur?

All equipment that generates, distributes or uses electricity produces EMFs, and these also occur naturally. Background EMFs are present in most homes. They come from the house wiring, electrical appliances and the low-voltage distribution cables that carry electricity along streets.

All overhead lines produce EMFs, and these tend to be highest directly under an overhead line and decrease to the sides at increasing distance. Underground cables produce no external electric fields, and the magnetic field falls more rapidly, falling to the levels typically found in UK homes within around 20 m compared to around 150 m for an overhead line. Substations and cable sealing end compounds do not produce significant EMFs outside their boundaries.

What are the health risks associated with living in close proximity to overhead lines/underground cables?

At National Grid, all of our equipment is designed to comply with the Government Guidelines and policies for Electromagnetic Fields (EMFs). National Grid fully recognises people’s concerns and takes this issue very seriously. National Grid relies on authoritative and independent scientific organisations such as the World Health Organization (WHO) and the UK Health Protection Agency (HPA) to review the worldwide body of scientific evidence on EMFs and health.

As far as EMFs are concerned, we discharge that responsibility by ensuring that our network complies with any appropriate independent safety standards, i.e., the exposure limits advised by the HPA and adopted by Government. For further information visit emfs.info.

Is it safe to bury cables underground?

High-voltage underground cables produce magnetic fields in the same way that overhead lines do, although the fields produced by cables fall more quicklu with distance as you move away than for overhead lines. Directly above an underground cable there will often be a higher magnetic field than will be found under an equivalent overhead line. Irrespective of the technology used National Grid will always ensure that all of its equipment is designed to comply with any appropriate safety standards i.e. the exposure limits advised by Public Health England and adopted by Government.

 

What measures does National Grid take to ensure the public is protected from the effects of EMFs?

National Grid takes the issue of health very seriously. We believe it is right that the decision on what is acceptable or not is made independently of industry. Accordingly, we design all our equipment, overhead lines, cables and substations to comply with Public Health England’s recommended exposure guidelines. A vast amount of research has been done into the possibility of health effects, without establishing any risks below these levels.

What impact do EMFs have on wildlife and animals?

The research that has been done on the impact of EMFs on wildlife and farm animals reveals no evidence that EMFs have a harmful effect on animals. This is reconfirmed in National Policy Statement EN-5 2011 which states:

There is little evidence that exposure of crops, farm animals or natural ecosystems to transmission line EMFs has any agriculturally significant consequences.

Construction

What is the latest timeline for Bramford to Twinstead?

A number of different scenarios for construction phasing of the project are currently under consideration. Certain components of the project that could fall under alternative planning regimes may be consented and constructed earlier than would be the case if those parts of the project were only within the application for development consent.

In particular, the GSP substation forms part of the proposed development for which application for development consent is sought. However, we are also considering the option of applying for planning permission for the GSP substation under the Town and Country Planning Act in advance of submission of an application for development consent.

We expect the construction period to be up to six years between 2022 and 2030, with differing potential start dates, depending on the different consenting approaches currently under consideration

While the phasing of the programme is yet to be confirmed, one of the first phases would be the construction of the GSP substation. This would need to occur prior to the removal of the existing 132 kV overhead line. The duration of the civil construction activities associated with the GSP substation would take approximately six to eight months within an18-month period allowing for works that can only be undertaken in planned electrical outages. The phases that follow construction and commissioning of the GSP substation would take approximately four years.

What will the impact be on local traffic?

The EIA includes an assessment on traffic and transport and the preliminary results are presented within the Preliminary Environmental Information Report, available in our Document library. This shows that the project would not generate large numbers of vehicles during construction. We are also looking at creating a haul route along the Order Limits, which would mean construction vehicles could track along the working corridor which would reduce the number of access points required onto the local road network and avoid the need to use some of the smaller, narrow lanes.

An Outline Construction Traffic Management Plan will be prepared as part of the application for Development Consent. This will set out the good practice measures proposed to further reduce impacts on the local road network and traffic. It will include measures providing clear signage to make sure our construction traffic uses the agreed routes and construction workers using public transport and car sharing where practicable. We emphasise to our employees and contractors the special care that they need to take when driving to and from the areas we are working in.

How will the noise of the construction impact local residents?

The EIA will include a noise assessment, which will identify areas where there could be the potential for significant noise effects. In these areas, there may be the need for mitigation such as noise barriers to reduce noise during construction. Further details will be set out within the Outline Construction Environmental Management Plan submitted with the application for development consent.

 

Will the construction result in air pollution that will disrupt local residents?

There is likely to be some effects on air quality during construction due to the number of construction vehicles and equipment including generators. Dust may also be generated during construction, due to soil stripping and vehicles tracking on the haul routes. The good practice measures set out within the Outline Code of Construction Practice, such as turning off machinery when not in use and locating equipment away from sensitive features, would reduce the effects on air quality. With such measures in place, there are unlikely to be any significant effects on air quality during construction. Further details can be found within the Preliminary Environmental Information Report, available in our Document library.

What will you be doing to mitigate the impact from HGVs on the local road network?

A Construction Traffic Management Plan will be developed in consultation with the Highway Authorities along the route. It will set out which routes we are allowed to use and steps to minimise disruption to local communities.  When it comes to construction, we will provide clear signage to make sure our construction traffic uses the agreed route and stays within the speed limit for construction traffic. We emphasise to our employees and contractors the special care that they need to take when driving to and from the areas we are working in.

Will there be local power cuts or interruptions to our electricity supply whilst the works are carried out?

No. The work will have no impact on your electricity supply. The work that we need to carry out is on part of the national transmission system and will have no direct effect on homes, businesses, schools and other premises in the local area.

What will we see when you are doing the work?

You would see our traffic management signs and vehicles on the roads where we need to access the works.

Our vehicles and equipment would be in the fields along the route of the new connection. There are likely to be excavators stripping soil and digging the trenches for the cables. There would also be cranes lifting the pylons and overhead lines in place. There would also be HGVs transporting materials around the working area.

What will be the working hours for the construction?

Normal working hours are expected to be between 07:00 and 19:00 Monday to Friday and between 08:00 and 17:00 at weekends and on Bank Holidays. It is anticipated that the exact hours of construction will be specified and controlled through the Development Consent Order.

Will you be closing any roads or footpaths?

For the safety of members of the public and our contractors we may need to close some public rights of way and roads temporarily. We will seek to provide alternative diversions and to keep the closure as short as practicable. The closures and any required diversions will be agreed with the local authorities and clearly communicated to local people.

Do you need to access my land?

We will contact landowners and occupiers to arrange access for environmental surveys to help inform how we develop our proposals.

Wherever we need to carry out surveys on private land, a member of our Land team or our agents will contact landowners and occupiers to discuss the type of surveys, the timing and duration before we start.

We look to agree access routes with owners and occupiers beforehand and comply with reasonable requirements for access and working practices.

If you own or occupy land where our works are proposed and wish to get in touch with our Land team about any aspects, you can contact them by phone on 01452 889000 or email at [email protected].

Timelines

How long is the consultation live?

Our statutory consultation will run for eight weeks, between 25 January 2022 and 21 March 2022. All responses to the consultation must be received before 23:59 on the closing date. Postal responses will be accepted up to five working days after this date.

How long was the reinforcement on hold for?

We put the reinforcement on hold in November 2013 and restarted work on the project in 2020.

What stage is the reinforcement in now?

The reinforcement is currently at the statutory consultation stage.

When is construction planned to start and finish?

A number of different scenarios for construction phasing of the project are currently under consideration. Certain components of the project that could fall under alternative planning regimes may be consented and constructed earlier than would be the case if those parts of the project were only within the application for development consent.

In particular, the GSP substation forms part of the proposed development for which application for development consent is sought. However, we are also considering the option of applying for planning permission for the GSP substation under the Town and Country Planning Act in advance of submission of an application for development consent.

We expect the construction period to be up to six years between 2022 and 2030, with differing potential start dates, depending on the different consenting approaches currently under consideration.

While the phasing of the programme is yet to be confirmed, one of the first phases would be the construction of the GSP substation. This would need to occur prior to the removal of the existing 132 kV overhead line. The duration of the civil construction activities associated with the GSP substation would take approximately six to eight months within an18-month period allowing for works that can only be undertaken in planned electrical outages. The phases that follow construction and commissioning of the GSP substation would take approximately four years.

Planning and regulation

What is a Development Consent Order (DCO)?

Nationally Significant Infrastructure Projects (NSIPs) are major infrastructure developments in England and Wales. These include projects such as power plants, large renewable energy projects, new airports, airport extensions and major road projects.

A Development Consent Order (DCO) application to undertake an NSIP is made to the Planning Inspectorate, who will consider the application and make a recommendation to the Secretary of State. The minister will decide on whether development consent should be granted for the proposed project.

In addition to development consent, a DCO can contain powers for compulsory acquisition, the need for which will be considered as part of the examination of the DCO.

How does the DCO application process work?

The process has six key stages:

  • pre-application
  • acceptance
  • pre-examination
  • examination
  • decision
  • post-decision

On receipt of an application for development consent, the Planning Inspectorate has 28 days to decide whether to accept it or not. There is then usually a period of around 3-4 months before the examination starts, and then a period of six months for the Planning Inspectorate to examine an application and three months for the Planning Inspectorate to make its recommendation to the Secretary of State. The Secretary of State has a further period of three months in which to issue a decision. The whole process from the date of application should take about 16 months.

Bramford to Twinstead project website route map Spring 2021

Reinforcement finance

Have you factored in socio-economic costs?

The Scoping Report set out the scoping assessment for Socio-economics, Recreation and Tourism (Chapter 15 of the Scoping Report). The Scoping Report assessed the potential for likely significant effects for different aspects, including potential effects on job creation and the availability of a local workforce, effects on tourism and recreation and amenity and also on navigation.

The Scoping Report concluded that the project would be unlikely to result in significant effects for any of the individual aspects within the Socio-economics, Recreation and Tourism chapter, when taking into account the embedded and good practice measures.

Grid supply point planning application

Why are you submitting a separate planning application for the GSP substation?

We need to build the Bramford to Twinstead Reinforcement to support the Government’s ambition to see 50 GW of offshore wind connected by the end of this next decade. The first stage of constructing the reinforcement will be to build the GSP substation – we need it in place before we can take down the existing 132 kV pylons. And, in turn, we need to remove some of these pylons to make space to build the new 400 kV reinforcement.

If planning permission is granted for the substation, we may be able to remove the 132 kV pylons sooner.

What’s the difference between this application and the application you will submit for the rest of the project?

We are applying for permission to build the GSP substation under the Town and County Planning Act. Applications of this nature are decided by the local council within which the application is located (Braintree District Council).

Consent for the wider Bramford to Twinstead Reinforcement will be sought through a development consent order application. This is a special type of application, designed for nationally significant infrastructure projects. Applications of this nature are examined by an independent inspector before the relevant Secretary of State (in this case, the Secretary of State for Business, Energy and Industrial Strategy) decides whether or not to approve the application.

Why do you need to build the GSP substation?

The existing 132 kV overhead line is the property of UK Power Networks, the distribution network operator in this area. In order to take down the existing 132 kV pylons, we need to provide UK Power Networks with a suitable replacement that will allow them to continue to supply electricity to homes and businesses. The GSP substation meets this requirement, and must be built before the 132 kV line can be removed.

What is happening with the application for the rest of the project?

Following the close of our recent statutory consultation, we have been carefully considering all feedback received and continuing our surveys and assessments. These surveys will build on the preliminary findings presented during our statutory consultation and, along with your feedback, will help to inform our design to be submitted as part of our application for a development consent order. We expect to submit our final application for the Bramford to Twinstead Reinforcement in winter 2022/23.