Frequently asked questions

Here you’ll find answers to some of the most frequently asked questions about EGL 3 and EGL 4.

We hope they answer your questions, and we will continue to update them as our proposals develop. If your question is not listed below, please get in touch with the team by emailing [email protected] or calling 0800 298 0405

About National Grid

    National Grid is an energy company operating in the UK and US. We deliver electricity and gas safely, reliably and efficiently to the customers and communities we serve – all while working towards a clean energy future.
    National Grid lies at the heart of a transforming energy system.
    Our business areas play a vital role in connecting millions of people to the energy they use, while continually seeking ways to make the energy system cleaner. National Grid Ventures and National Grid Partners also enable innovations to help revolutionise and decarbonise the future of energy.

    Follow this link to learn more -

    National Grid Electricity Transmission (NGET) sits at the heart of Britain’s energy system, connecting millions of people and businesses to the energy they use every day. Every time a phone is plugged in, or a switch is turned on, we’ve played a part, connecting you to the electricity you need.

    It is NGET that is developing plans for EGL 3 and EGL 4 in England and English waters. 

    Follow this link to learn more. 

    The 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 the 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. In April 2019, the ESO became a legally separate business within the National Grid Group and is regulated independently by Ofgem.

    Follow this link to find out more  - 

    The Great Grid Upgrade is the largest overhaul of the electricity grid in generations. Our infrastructure projects across England and Wales are helping to connect more renewable energy to your homes and businesses.

    The Great Grid Upgrade will play a big part in the UK government’s plan to boost homegrown power. It will help the UK switch to clean energy and make sure our electricity network is fit for the future; carrying more clean, secure energy from where it’s generated to where you need it.

    Both EGL 3 and EGL 4, along with several other projects including Grimsby to Walpole, EGL 1 and EGL 2, are critical parts of this upgrade. 

    Follow this link to find out more - 

    National Grid funds new projects such as power transmission lines through an agreement with Ofgem. They pay upfront costs, which are gradually passed to customers over 40 years, easing the burden on electricity bills. Investors support National Grid, expecting profits and eventual repayment. This spreads the investment cost over years, avoiding sudden bill spikes.

    The bill you receive from your energy supplier is made up of a number of separate charges. Some of these charges are based on the different stages through which electricity makes its way from the producers to your home. In 2022/23, £19.70 of the annual household bill was for operating, maintaining and investing in the national electricity transmission system. This charge is set by the energy regulator Ofgem and is not affected by the price of energy. Around £100 of your annual household energy bill goes to the local distributor to build, maintain and invest in the local electricity network.  

    About EGL3 and EGL4

      EGL 3 and EGL 4 are two new primarily offshore high voltage electricity links, with associated onshore infrastructure, between Scotland and England.

      EGL 3 and EGL 4 are essential network reinforcements needed to deliver on the UK’s net zero target – without it, low carbon, renewable energy generated in Scotland, mostly from offshore wind, would not be able to be transported to the homes and businesses that need it. 

      EGL 3 and EGL 4 would help connect renewable sources of energy to homes and businesses helping to deliver 50 GW of offshore wind by 2030 and ultimately net zero.

      There is no fully offshore solution to connect power generated or transported offshore to the Grid. We have to bring the power onshore somewhere. Our job is to carefully consider the most feasible options and present proposals for public consultation, which go as far as possible to address impacts on local communities and the environment, and also deliver for electricity consumers.

      The electricity, grid built predominantly in the 1960s, wasn't designed to transport renewable energy from different sources, or meet the forecast increase in demand because of decarbonisation, so it has to be upgraded.

      We continue to consult with local communities and will always endeavour to reduce impacts as much as possible so that we can deliver this infrastructure, which is vital for the country as a whole.

      EGL 3 and EGL 4, and the other projects that form The Great Grid Upgrade will play a big part in the UK government’s plan to boost homegrown power. It will help the UK switch to clean energy and make sure our electricity network is fit for the future; carrying more clean, secure energy from where it’s generated to where it is needed.

      Through extensive surveys and research, we considered several potential landfall sites along the Lincolnshire and North Norfolk coastlines. In doing so, we identified that our indicative route combines a relatively direct route to our proposed infrastructure near Walpole and Bilsby, including our connection points into the grid, with the least disruption to local communities and the environment. 

      Our indicative route travels mainly through agricultural land, which, for the majority, will only be temporarily impacted. It avoids larger settlements (such as Skegness, Boston and King’s Lynn), on land and marine nature reserves and designations (such as the Wash National Nature Reserve and Gibraltar Point Nature Reserve), RAF Holbeach Air Weapons Range and the Norfolk Coast AONB.

      One of these projects could also connect to the transmission network near Bilsby, in East Lindsey, providing greater flexibility and resilience to the network as a ‘three-ended’ connection. As we are still in the early stages of the projects, it has not fully been confirmed that this connection is required.

      From the outset, we (NGET) have sought to coordinate these two projects to reduce their community and environmental impacts. By co-locating both, we could reduce the total cable construction swathe by up to 20m. 

      Indirectly, NGET is also co-ordinating with other projects in Lincolnshire, most notably the Outer Dowsing offshore wind farm project. An example of this is where EGL 3 and EGL 4 are currently choosing not to route their HVDC underground cables to the south-east of Boston where physical space available between Boston and The Wash is constrained, and a crossing (in addition to that by the Outer Dowsing OWF Project) of The Haven main river would present particularly complex engineering challenges. 

      National Grid Electricity Transmission (NGET) is required under the Electricity Act 1989, to find a balance, developing proposals that are efficient, coordinated and economical, and which have regard to the preservation of amenity. Each network upgrade must be considered on its individual merits, as required in planning law. 

      The national policy statement (NPS) which covers developing new electricity networks infrastructure (EN-5) states that the Government expects overhead lines will often be appropriate and that is the starting presumption we work to. 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.  

      In this case, our assessment of EGL 3  and EGL4 concludes that, on balance, an underground cable solution is most appropriate.

      Detailed information on the need and options assessed for the Grimsby to Walpole project can be found on the project website.

      2024 – Stage 1 (non-statutory) public consultation

      2025 – Stage 2 (statutory) public consultation

      2026 – DCO application submission

      2028 – Construction starts

      2033 – Fully operational

      Local communities and the environment

        EGL 3 and EGL 4 are set to deliver significant benefits to the community by enhancing the UK's energy security, supporting the transition to a low-carbon energy system, and facilitating the connection of new sources of renewable energy. The projects contribute to the national goal of decarbonisation, which in turn helps combat climate change and reduces reliance on fossil fuels. Local communities will also benefit from the investment in local infrastructure and the potential for biodiversity net gain and environmental improvements associated with the projects.

        The impacts on the local community during the construction of EGL 3 and EGL 4 are primarily temporary. National Grid takes measures to minimise disruption to residents and the environment during this period, including managing traffic, noise, and visual impacts. Once construction is completed, efforts are made to restore and, in some cases, enhance the affected areas. Permanent impacts are carefully considered and mitigated through the project design and consultation process, aiming to achieve a net positive outcome for communities and the environment.

        EGL 3 and EGL 4 are essential network reinforcements needed to deliver on the UK’s net zero target – without it, low carbon, renewable energy generated in Scotland, mostly from offshore wind, would not be able to be transported to the homes and businesses that need it. 

        EGL 3 and EGL 4 would help connect renewable sources of energy to homes and businesses helping to deliver 50 GW of offshore wind by 2030 and ultimately net zero.

        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.

        Some people worry that Electromagnetic fields (EMFs) may have negative health effects. We take these concerns seriously and want to keep the public, our contractors and employees safe.  We ensure all of our existing and proposed equipment, including those on this project, comply with independent safety guidelines set to protect us all against EMF exposure. After decades of research the weight of evidence is against there being any health risks of EMFs below the guideline limits. 

        For further information on EMFs visit our website, If you would prefer to talk about your concerns, please do not hesitate to call the EMF helpline on 0845 702 3270 or email [email protected].

        The EGL 3 and EGL 4 projects are both in a very early stage of design, however we will thoroughly consider the environmental impact of the projects before we submit our application for development consent. An Environmental Impact Assessment (EIA) will be undertaken and this forms a core part of the planning process, assessing the potential effects on biodiversity, landscape, air quality, water resources, and cultural heritage, among other factors. The findings of the EIA (alongside feedback from stakeholders) informs our project routing and design, enabling us to avoid, minimise, or mitigate negative impacts. We engage with environmental stakeholders  to gather feedback and incorporate it into our planning and mitigation strategies. During our next stage of public consultation, we will publish the initial findings of this environmental assessment in a document called the Preliminary Environmental Information Report (PEIR).  At that stage we will seek your views on our comprehensive assessment, and feedback received will inform the final Environmental Statement (ES) submitted as part of the DCO application.

        All construction schemes have a target of delivering 10% Environmental Net Gain (which must include a minimum of 10% Biodiversity Net Gain). As outlined by Natural England, Biodiversity Net Gain (BNG) is an approach to development, land and marine management that leaves biodiversity in a measurably better state than before the development took place.

        Onsite: Within the project’s development area 


        • land owned by the National Gid 
        • land leased by the National Grid.

        We recognise the importance of the UK's food security and are committed to minimising the impact of our projects on high-quality farmland. Our planning and construction methodologies are designed to protect and preserve the agricultural value of the land we work on. Where impacts are unavoidable, we implement measures to restore the land to its original – or an improved condition – post-construction, aiming to maintain its agricultural productivity.

        National Grid considers the potential impact on tourism as part of the environmental and socio-economic assessment of the projects. This includes evaluating the visual impact, construction activity, and any temporary disruptions. Efforts are made to mitigate negative effects through careful planning, design, and consultation with local stakeholders and tourism bodies to ensure the projects align with regional economic interests and community values.

        Infrastructure and construction

          A converter station houses the technology that converts electricity between DC and AC, enabling it be transmitted over long distances. AC current is used in each country’s transmission system to power homes and businesses, while DC is used for sending electricity more efficiently over long distances.

          Substations house electrical equipment which enables the system operator to control the flow of electricity. These substations come in many sizes and configurations depending on the need. 

          Substations are used to transport power securely from where it is generated to where it is needed. Substations are also key in helping to isolate and fix faults and allow maintenance to be undertaken safely on the electricity network.

          A direct current switching station is equipment used to tie together two or more electric circuits through switches, allowing electricity to be sent to two or more locations. 

          A variety of methods can be used to lay the high voltage direct current (HVDC) and high voltage alternating current (HVAC) underground cables, including ducted and trenchless methods.

          In the ducted method, we would first dig a trench (typically 2.5m wide and 0.9m deep) carefully removing the soil in layers. Then we would install the ducts within the trench, covering them by carefully replacing the soil. The cables would then be pulled through the ducts. This approach minimises the length of time soils are exposed. Where necessary, trench depths may be deeper. This will be determined through feedback from consultation,  information from surveys and ongoing design studies.

          Trenchless methods, such as such as Horizontal Directional Drilling (HDD), allow us to install cables while minimising interaction with the land surface, which reduces the impact on wildlife, traffic, and local communities. Use of HDD or other trenchless methods depends on local conditions and any obstacles we need to overcome.

          We will develop a traffic management plan that will ensure that movements of people, plant and materials are achieved in a safe, efficient, timely and sustainable manner and ensure construction traffic levels do not exceed an acceptable level. We will work closely with the local authority and take guidance to help reduce any potential impacts.

          Proposed working hours will be included within the environmental impact assessment. The exact timings will form a requirement of the Development consent order. We will do as much as we can to keep disturbance to the local community to a minimum. 

          We don’t anticipate closing any public footpaths permanently, but we would likely need to redirect some public rights of way during the construction phase and possibly permanently. Our traffic management plan will set full details of where and when these will be implemented. We will keep the community informed at all times and provide as much notice as possible.


            In the DCO process, anyone with a legal interest in land is known as a Person with an Interest in Land (PIL). If you are identified as a PIL, we will contact you directly.

            Whilst much of the information we need to confirm a legal interest on is available on public registers, we have appointed land referencing firm Ardent to contact individual landowners to verify the publicly available information and ensure NGET has have made best efforts to identify any potentially impacted landowners.

            Ardent will also assist with contacting landowners and occupiers to arrange access for non-intrusive and intrusive surveys which we plan to carry out from summer 2024.


            Coordinating consultation periods across different projects can be challenging due to differences in project timelines, stages of development, and regulatory milestones – even if they are closely located together.

            The proposals for Grimsby to Walpole are at a more advanced stage and have always been ahead of the proposals for our Eastern Green Links projects. Both projects must be progressed on their own timescales as they address different network requirements, and to be in service as close to 2030 as possible. 

            National Grid did consider joint consultations, but it was felt that because the timescales were different, that different locations may be needed for each project and the amount of material that might need to be presented by both projects at one time means that separate consultations are best in terms of overall approach.  

            The key elements of our proposals for consultation include:

            Two co-located HVDC underground cable routes, from one of two potential landfall locations on the Lincolnshire coastline. From landfall, one of the routes would branch-off to connect via a proposed converter station and direct current switching station site near Bilsby, within East Lindsey, and then run to one of two proposed new converter stations in the Walpole area, of Kings Lynn & West Norfolk; and the other underground cable route would run from landfall to connect directly into the other proposed converter station within the Walpole area.

            One new converter station and direct current switching station near Bilsby, East Lindsey. The route of high voltage alternating current (HVAC) underground cables to connect the converter station and direct current switching station to a new substation in the Walpole (also proposed as part of NGET’s Grimsby to Walpole project) and onto the electricity network. Two new converter stations in the Walpole area, the route of two separate HVAC underground cables to connect the proposed converter stations to the proposed substation in the Walpole area, and into the electricity transmission network. 

            One new substation in the Walpole area (also proposed as part of NGET’s Grimsby to Walpole project) and potential converter station design approaches that we could consider during the later design stages.

            Consultation opens Tuesday 23 April 2024 and will close at 11:59pm Monday 17 June 2024.

            One of the objectives of this consultation is to seek your views on our emerging proposals. All feedback we receive is carefully considered, along with the outcome of technical studies and environmental assessments as we refine our proposals.  We will present our refined proposals at our statutory consultation that we plan to hold in 2025.  When we launch our statutory consultation, we will publish a consultation report that will outline the feedback we have received, how we had regard to this as we developed our proposals, and any resulting changes to our proposals.

            All projects change to a greater or lesser extent as they progress through the planning process. For example, when our Norwich to Tilbury reinforcement was launched in 2022, we were proposing approximately 170 km of overhead line and 10 km of underground cable through the Dedham Vale AONB. 

            As a result of the feedback given, and further technical work undertaken following the consultation, an additional stage of consultation was held in Summer 2023. At this consultation, we presented updated proposals which included an increase in the amount of underground cable proposed to approximately 25 km.