Here you’ll find answers to some of the most frequently asked questions about the Grimsby to Walpole project.


We’ll update these as our work progresses and we hope they answer your questions about this project.

General information

Who is National Grid?

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 (NGET), owns, builds and maintains the network in England and Wales. It's NGET that's developing plans for the Grimsby to Walpole 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.

What is National Grid Electricity Transmission (NGET)?

NGET owns, builds and maintains the high-voltage electricity transmission network in England and Wales. This network operates primarily at 400,000 volts (400kV) and 275,000 volts (275kV).

It's NGET that is developing plans for the Grimsby to Walpole reinforcement and is the electricity transmission arm within National Grid.

What is National Grid ESO?

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.

What are National Grid Ventures?

National Grid Ventures (NGV) operate a mix of energy assets and businesses to help accelerate the development of our clean energy future, such as undersea interconnectors that allow the UK to share energy with other European countries.

What is The Great Grid Upgrade?

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

Where can I find out more information about The Great Grid Upgrade?

You can visit for more information.

What are National Grid Electricity Transmission’s (NGET’s) policies when working in the UK?

NGET’s commitments when undertaking works in the UK can be found in our Stakeholder, community and amenity policy: Commitments when undertaking works in the UK.

What are National Grid Electricity Transmission’s (NGET’s) obligations?

NGET’s statutory obligations are set out in the Electricity Act 1989 (the Electricity Act) and its Transmission Licence. We must develop and maintain an efficient, coordinated and economical transmission system, and have regard to the desirability of preserving amenity. We must also plan the network in accordance with security and quality of supply standards.

Anyone can apply to National Grid ESO to connect new sources of electricity in any part of Great Britain. NGET and the System Operator have a statutory obligation to respond with a connection offer.

In planning new connections and network reinforcements, we must carefully balance our statutory duties and ensure our proposals meet the security and quality of supply standards. Potential options to add to or reinforce the network are therefore evaluated against these obligations.

Who regulates National Grid Electricity Transmission (NGET)?

We 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 (GEMA) and 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 shares 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 Energy Security and Net Zero (DESNZ)?

DESNZ, is a ministerial department responsible for delivering security of energy supply, ensuring properly functioning energy markets, encouraging greater energy efficiency and seizing the opportunities of net zero to lead the world in new green industries.

Following the Government’s ‘Ten Point Plan for a Green Industrial Revolution’ in December 2020, an energy white paper entitled ‘Powering Our Net Zero Future’ was published, setting out how the UK will clean up its energy system and reach net zero emissions by 2050. In the British Energy Security Strategy published in April 2022, Government increased the ambition to see 50GW of offshore wind connected by 2030. DESNZ works alongside Ofgem in setting the framework, within which National Grid ESO, National Grid Electricity Transmission (NGET) and the wider energy sector operate.

What is Government’s Offshore Transmission Network Review?

Government’s Offshore Transmission Network Review is currently looking at how the offshore electricity transmission network can be delivered in a more coordinated way to deliver net zero emissions by 2050, and we fully support that work. We will work closely with Government, stakeholders and coastal communities to ensure we play our part to deliver the infrastructure needed to achieve net zero in a way that reduces impacts on communities. 

In meeting that challenge there are two key considerations. The first is the way in which we best connect and coordinate the growth of offshore wind farms and interconnectors to the electricity transmission network along the immediate coastline. The second is the network reinforcements required further inland to accommodate the increased demand on the network and to ensure we can effectively transport the power to where it is needed across Great Britain.

That offshore coordination work by Government is ongoing. As explained in the Energy White Paper, Government will be looking to redesign the current regime to bring more extensive coordination and mitigate environmental, social and economic costs for the 2030s and beyond.

While developers are encouraged, where early opportunities for coordination exist, to consider becoming pathfinder projects, National Grid ESO explains in the latest Network Options Assessment, that there are a significant number of onshore reinforcement projects needed to meet the 2030 ambitions. A large number of those are considered ‘essential’ to achieving those ambitions, including this proposed network reinforcement in Lincolnshire.

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 Government, industry and consumer groups to help deliver a net zero economy at the lowest cost possible to consumers.

Further information about Ofgem is available on its website or you can call the Consumer Affairs team on 020 7901 7295 or email [email protected]. 

What is the Holistic Network Design (HND)?

On 7 July 2022, National Grid ESO published its Pathway to 2030 Holistic Network Design (HND), which recommends an optimal transmission network arrangement to support the large-scale delivery of electricity generated from offshore wind over that period, taking power to where it's needed across Great Britain.

The HND provides connection recommendations for 23GW of offshore wind and the associated transmission network infrastructure required to get the power to where it's needed. With existing installed offshore wind capacity and other projects that are advanced in their development, the HND will help deliver the Government’s ambition for 50GW of connected offshore wind by 2030.

In developing the HND, the National Grid ESO is bringing together onshore and offshore network planning to allow the development of engineering solutions for the country’s transmission infrastructure that connects offshore wind projects to the network in a coordinated way.

The objectives for the development of the HND are that it should be cost-efficient and deliverable, but also to minimise the impact new coordinated infrastructure has on communities and the environment.

What is the Network Options Assessment (NOA)?

The Network Options Assessment (NOA) is an annual report published by National Grid ESO which outlines their recommendations for network reinforcement projects to take forward during the coming year. The NOA 2021/22 Refreshis the latest update and was published in July 2022 as part of the Pathway to 2030 Holistic Network Design suite of documents.

When new editions of the NOA are released, National Grid Electricity Transmission takes account of the recommendations in considering where it needs to reinforce the network and will back check and review the need case for projects that are in progress.

Project specific questions

Why is the project needed?

Currently the UK is home to the largest operating offshore wind capacity in the world at around 14.7 GW. As a country we also already have around 15.2 GW of solar connected. Government, as set out in the British Energy Security Strategy, is looking to increase the amount of electricity coming from offshore wind to 50 GW by 2030 – more than enough to power every home in the country. The British Energy Security Strategy also sets a target for up to 70 GW of solar by 2035. 

This growth in renewable energy generation, coupled with greater interconnection between our transmission network and networks in other countries, in line with the Government’s net zero agenda, is driving a need to increase the capability of our transmission system, as power flows are set to exceed the capability of the existing network in the next decade. 

Grimsby to Walpole will increase the capability of the network to carry clean green energy from the north of England to the Midlands and the South. It is also required to carry power from offshore wind farms, interconnectors, solar/ battery storage proposals and HVDC links that are planned to connect to the network. 

Without additional network capability, offshore wind and interconnectors would be constrained off at times of high wind generation and high imports. The Electricity System Operator would need to do this in that scenario, because these sources of power would produce more energy than is needed and, than can be safely and securely handled by the existing transmission system. The cost of that – paying wind farms or interconnectors not to generate or transport electricity and paying others to generate in other areas – is ultimately passed to consumers. Operation of the network would also become sub-optimal in the long term. Less efficient and more carbon intensive sources of generation would potentially be used at those times, hindering progress toward net zero. 

How is the need for the project identified?

The Network Option Assessment (NOA) provides the Electricity System Operator’s recommendations for which network reinforcement projects should be taken forward and for when. The 2021/22 NOA Refresh recommends the most economic investment strategy for these network reinforcements and outlines the pathway to 2030 and beyond.

As part of this refresh, The Midlands, South and East of England – which covers areas spanning from the Humber in the North to East Anglia and the Thames Estuary in the south – have been identified as areas in need of network reinforcement to enable the connection of more offshore wind on the East Coast.

Grimsby to Walpole forms an important part of our plans in this region – helping increase power flows from the North to the Midlands and facilitating the connection of offshore wind and interconnectors. We are now working to determine the most suitable areas for this network reinforcement, which involves routeing a new overhead line from Grimsby to the Walpole area.

How will you keep local people informed?

We will keep this website updated with information on our proposals. You can also register your email to be provided with project updates.

Before we hold our first stage of public consultation, we will write to local communities along the route with more details on how you can get involved.

What community benefits will you be providing?

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 therefore hope that the 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.

Why aren’t you putting the proposed reinforcement in the sea and building an offshore link instead?

Our Strategic Options Report explains how we have considered all available options, including offshore alternatives. 

The estimated capital cost of a subsea alternative, including substations, is approximately £4.4bn, significantly greater than the approximately £1.1bn cost of the onshore option we are proposing. 

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.

Why aren’t you putting the proposed new line underground?

Our Strategic Options Report explains how we have considered all available options, including underground alternatives. 

The estimated capital cost for underground alternative, including substations, is approximately £6.5bn, significantly greater than the approximately £1.1bn cost of the onshore option we are proposing. 

Existing and proposed national policy recognises that overhead lines are often appropriate, except in particularly sensitive locations such as Areas of Outstanding Natural Beauty. 

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.

Why can’t you put more wires on existing pylons?

The only existing sections of high voltage transmission network in Lincolnshire, south-east Cambridgeshire and west Norfolk are: 

  • two double circuit overhead lines running from Grimsby West, South Humber Power Station, and Immingham and Killingholme B power stations, to Keadby substation in North and North East Lincolnshire, and  
  • a section of the double circuit line from West Burton in Nottinghamshire, to the Bicker Fen substation in Lincolnshire, and then onto the existing Walpole substation in Norfolk. 

 There is no existing transmission infrastructure along the emerging preferred corridor from Grimsby West until south of Bicker Fen, near Quadring that can be upgraded. 

 The existing overhead lines running north-west from the Grimsby West, South Humber, Immingham and Killingholme area, are already carrying significant generation out of the area. Taking more that way would not address the power flow challenges that the network will have in the next decade. 

 The existing pylons from Bicker Fen to Walpole are designed to carry two separate electrical circuits, one on either side of the tower. They cannot carry more circuits and already are designed to carry as much power as possible while operating to the Security and Quality of Supply Standards that the network is operated to. 

Do you support Government’s proposals for community benefit set out in the Autumn Statement 2023, and will you adopt their guidance on your projects?

Communities are playing a fundamental role in the energy transition, and we believe those that host energy infrastructure should receive fair and enduring benefits for doing so. 

We welcome the Government’s intention to introduce guidance and believe this will create greater clarity and consistency. 

The guidance should be flexible, ensuring developers can work together with local communities and stakeholders to deliver community benefit schemes which are tailored to local need. For example, this could include supporting local community projects as well as delivering broader socioeconomic and environmental enhancements. 

We continue to stress the urgent need for the guidance to be published quickly, given the pace at which the infrastructure needs to be developed. 

We will continue to work with the Government and regulator as they define the details of these schemes and, once published, will work to understand what this means for our projects. 

How can I provide feedback?

During our Stage 1 public consultation you could provide your feedback to us in a number of ways:

  • download and print a copy of our feedback form post it back to us at Freepost G TO W (no stamp or further address required). You can also pick up a paper feedback form from any of our face-to-face public consultation events or public information points. Alternatively you can request a consultation pack (newsletter, feedback form and freepost envelope) to be sent to you in the post. scan your completed form and return it via email to [email protected]
  • download our interactive feedback form here and return it via email to [email protected]
  • email us at [email protected]
  • send a letter to Freepost G TO W (no stamp or further address required)

If you have difficulty writing down your feedback, a member of the Community Relations team will be able to take comments over the phone (0800 0129 153).

What about EMFs? Is there any risk to health?

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’s 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.


What surveys are you carrying out?

We are carrying out several different types of surveys for Grimsby to Walpole. Please see the below for a table of surveys currently planned for May and the approximate locations where these will be carried out.

Survey typeSurvey locations planned within the month
Breeding birdsCorridor wide
Great Crested Newts eDNA and Habitat Suitability Index (HSI) SurveyCorridor wide
UK Habitat ClassificationSubstation siting zone locations
Water voleCorridor wide
OtterCorridor wide
Bat - Static detector surveySubstation siting zone locations
Drainage SurveyCorridor wide
Geophysical surveySubstation siting zone locations
When are surveys taking place?

Some ecological and environmental surveys can only be carried out at specific times of the year. For example:

  • Breeding bird surveys are usually carried out between mid-March to July as they target key species and territories of birds.
  • Great crested newt surveys must be undertaken between 15 April – 30 June, to align with the breeding period of newts, when they are more likely to inhabit a pond.
  • UK Habitat Classification surveys can be undertaken all year round, however there are some habitats which have key seasonal constraints. Starting in April allows the surveyors to survey some key habitats e.g. hedgerows.
  • Ground level tree assessments for bats in April are required to inform the scope of potential further bat surveys over the summer months.
  • Water vole surveys are usually carried out between mid-April and September as this is when they are most active.
  • Geophysical surveys are best carried out in late Spring to early Summer as conditions underfoot should not be waterlogged and later in the summer crops have grown to an extent that they are at risk of damage by the survey equipment
Where are the surveys taking place?

At this early stage, before we have a more detailed proposal, surveys are taking place within the emerging preferred route corridor and potential substation siting zones.

Do you have permission to carry out surveys?

National Grid endeavours 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. 

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’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.