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

We hope they answer your questions and we will continue to update them as our work progresses. If your question is not listed below, get in touch with the team using the details provided on the Contact us page.

About National Grid

Who is National Grid?

National Grid is a group of companies, and one of those companies, National Grid Electricity Transmission, owns, builds and maintains the network in England and Wales. It is this company that is developing plans for the Sea Link reinforcement.

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?

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

It is NGET that is developing plans for the Sea Link reinforcement and is the electricity transmission arm within National Grid.

What is National Grid ESO?

The Electricity System Operator (ESO) is legally separate from the rest of National Grid and ensures that Great Britain has the essential energy it needs by making sure supply meets demand every second of every day.

What is National Grid Ventures?

National Grid Ventures (NGV) operates 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 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 here: commitments when undertaking works in the UK

Why is National Grid reinforcing the transmission network?

The Government’s ten point plan for a green industrial revolution, together with the net zero strategy and the British energy security strategy, is driving unprecedented investment into new renewable and low carbon electricity generation. This includes the target of up to 50 gigawatts (GW) of offshore wind generation by 2030. At the same time, electricity demand is set to increase as other sectors of the economy move away from fossil fuels and increasingly rely on renewable and low carbon electricity. This will put significant pressure on the national electricity transmission system, the network of pylons, substations and cables that takes energy from where it’s generated to where it’s used. The network needs to be reinforced so that electricity continues to flow securely and reliably around the UK. NGET is planning several major reinforcement projects needed to meet this challenge; Sea Link is one of those reinforcements.

About Sea Link

What is Sea Link?

Sea Link is an essential upgrade to Britain’s electricity network in East Anglia and Kent using subsea and underground cable. The proposal includes approximately 130km of subsea cables between Sizewell area in East Suffolk and Richborough in Kent. At landfall, the cables would go underground for up to 5 km to a converter station (one at each end). The converter station converts direct current used for the subsea section to alternating current, which our homes and businesses use. A connection is then made to the existing transmission network. In Suffolk, via the proposed Friston substation; in Kent via a direct connection to the overhead line between Richborough and Canterbury.

Why is Sea Link needed in Suffolk and Kent?

We are at the initial development stage of our Sea Link project which seeks to reinforce and strengthen the network between Friston in Suffolk and Richborough in Kent to carry renewable and low carbon power to homes and businesses. We developed much of the existing network in East Anglia and Kent in the 1960s and it does not have sufficient capacity to carry future renewable and low carbon power that’s forecasted to connect to the network – from offshore wind, interconnectors and nuclear power.

We need to upgrade the electricity network to carry this extra power.

What is the project timeline?
Sea link timeline
Why is Sea Link being proposed to connect in Suffolk?

Government policy is driving a sizeable shift towards low carbon and renewable generation. Significant amounts of this new generation is planned along the east coast in this decade including a 4 fold increase in offshore wind from 11 GW today to up to 50 GW by 2030.

We need to facilitate the export of increased power out of East Anglia. The existing transmission network was not designed and built with the envisaged amount of power in mind and therefore it needs to be reinforced.

National Grid is proposing several network reinforcement projects of which Sea Link is one.

Sea Link is proposed to connect into the proposed Friston substation as this part of the network has a concentration of planned generation and connecting Sea Link here offers additional consumer benefit as it is able to carry an additional 2 GW out of the area should system conditions need it to.

Why is Sea Link not connecting to Bradwell?

Sea Link has been developed in response to the identified need to reinforce the EC5 network boundary, ensuring it is able to safely cope with the planned increase in generation in this area. This means that if Sea Link did make landfall at Bradwell, significant physical infrastructure would be required to bring this connection from Bradwell to within the EC5 boundary, otherwise Sea Link would not meet the aims and objectives of the project which is to create additional capacity within this specific location. The full needs case can be found in the project background document. 

Connecting at Bradwell would not meet the need of the Sea Link project as defined in the Network Options Assessment.  Sea Link is tasked with reinforcing several network boundaries including two in East Anglia - EC5 and EC6. To achieve this Sea Link needs to connect into the Sizewell area, and the proposed Friston substation is our proposal. Connecting Sea Link into the East Anglia Green proposed substation at Ardleigh does not support the reinforcement of the EC6 boundary. 

Why is Sea Link not connecting to Bramford?

Connection at Bramford would be less economic and efficient than a connection at Friston.

Why is Sea Link being connected in Kent? Why at Richborough?

During periods of high wind generation from offshore wind farms on the east coast, electricity will need to be exported to Europe via interconnectors to balance the electricity network. Many of these interconnectors are located along the south east coast of the UK.

In the future there will be insufficient network capacity in the region to get power into the UK network to and from the South East Coast when interconnectors are importing and exporting. Sea Link will provide the additional network capacity needed to enable the import and export of wind energy to and from Europe.

Why have you not considered brownfield sites and/or other national grid substations?

We have been unable to find any brownfield sites within the Converter Station Option Area that are suitable for the infrastructure proposed. All existing National Grid substations in the area are already at capacity or do not have the space around them to allow the connection required by this project.

Planning and consultation

What can I influence?

Our non-statutory consultation is now closed. In the coming months, our team will analyse the feedback received during non-statutory consultation and undertake further technical work and surveys to inform changes to our proposals. You will have a further opportunity to provide your feedback on our refined proposals in 2023. 

How are you going to seek planning permission to build Sea Link?

​NGET has received a Section 35 Direction from the Department for Business, Energy and Industry Strategy (BEIS) that confirms Sea Link should be dealt with as being “nationally significant” and be treated as development for which development consent is required under the Planning Act 2008. The application is made to the Planning Inspectorate, who hold hearings to examine the proposals and make a recommendation to the Secretary of State. The minister will decide on whether a development consent order (DCO) should be granted for the proposed project.  In addition to development consent, a DCO can contain powers for compulsory acquisition of land, the need for which will be considered as part of the examination of the DCO. ​

How are you coordinating with other projects?


We are exploring options to co-locate Sea Link infrastructure with NGV’s Eurolink and Nautilus projects – project buildings, cable corridors and landfall locations. We are also committed to exploring how we can coordinate our activity with other developers, like ScottishPower Renewables and EDF.


We are also exploring the potential for offshore coordination as part of the Offshore Transmission Network Review (OTNR) ‘Early Opportunities’ workstream. Sea Link, which is a reinforcement of Britain’s UK transmission network, is needed irrespective of offshore coordination. More broadly, significant reinforcement of onshore infrastructure is key to enabling a clean low carbon future.

How are NGET/NGV/SPR/EDF proposing to work together to minimise total construction impact, on both the environment, and on local communities?

We are exploring potential options to co-locate Sea Link infrastructure with NGV’s EuroLink and Nautilus projects – project buildings, cable corridors and landfall locations to reduce impact on communities and the environment. We are also committed to exploring how we can coordinate our construction activity with other developers, like SPR and EDF.

What does coordination with EuroLink and Nautilus mean?

In response to stakeholder feedback, NGET’s Sea Link project and NGV’s EuroLink and Nautilus projects are exploring potential opportunities to coordinate.

Coordination could range from co-location of infrastructure from different projects on the same site, to coordinating construction activities to reduce potential impacts on local communities and the environment.

Local communities and environment

What will be the cumulative effects of all these projects on the East Suffolk communities, and what are you proposing to do to mitigate and compensate for those effects?

We are exploring potential options to co-locate Sea Link infrastructure with NGV’s EuroLink and Nautilus projects – project buildings, cable corridors and landfall locations to reduce impact on communities and the environment. We are also committed to exploring how we can coordinate our construction activity with other developers, like SPR and EDF. National Grid is committed to being a good neighbour and we fund projects run by charities and community groups that meet local community needs by providing a range of social, economic and environmental benefits.

What community benefit are you proposing to offer us?

We believe that business needs to stand for something more than profitability, and we are committed to leaving a lasting positive legacy for the communities in areas where we build and maintain our infrastructure. Our infrastructure projects and daily operations allow us to give back to communities who are impacted by our works through our Community Benefit Plan. The Community Benefit Plan is a framework of activities that show National Grid is listening, is committed to leaving a positive legacy and enabling an equitable future for the communities we serve.  

The Community Benefit Plan is split into four distinct pillars, each comprising several initiatives and schemes. These pillars are: 

  • Grid for nature - Developing green space for local and deprived communities to use and enjoy. Consists of the Woodland Strategy & Great British Bee Project initiatives, several regional/national partnerships, and green leases.  
  • Net Zero Heroes - Forming strong local partnerships with stakeholders close to our projects and through our in-house expertise, to help them realise their own climate ambitions.  
  • Skills/STEM - Seeking regional partnerships with suppliers to part fund the establishment of training centres and flexible training programmes to help give the next generation the skills they need to be part of the Net Zero Energy Workforce. Additionally, we will engage with schools and colleges through site visits, grants, and innovative targeted programmes that are aligned to the curriculum. 
  • Community benefit - Funding community projects that provide social, economic, and environmental benefits to local communities, ensuring we leave behind a positive legacy.  

The initiatives within the NGET Community Benefit Plan are also aligned to National Grid’s Responsible Business Charter, which focuses on five key areas where we can really make a difference: the environment, our communities, our people, the economy and our governance. These focus areas underpin our new strategic priorities and make sure that responsibility is woven through everything we do.  

Will EMF from the Sea Link project affect my health?

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].

Have you considered the environmental impact?

Regarding designated wildlife sites on the Suffolk coast, we will carefully review the impact of our proposals on designated sites and the environment as a whole.  

We will demonstrate to statutory and non-statutory stakeholders our application of the “mitigation hierarchy”, which is to aim to avoid, then minimise, restore/remediate and lastly offset impact throughout the development of Sea Link in order to mitigate the impacts of our activities. This could include but is not limited to micro siting the cables to avoid sensitive locations, undertaking activities at certain times of the year, proposing less intrusive construction methods, and fulfilling our commitment to deliver 10% Biodiversity Net Gain. 

We will carry out a full Environmental Assessment to consider any potential impacts and how best to mitigate or reduce them. The proposals will be fully compliant with the Infrastructure Planning (Environmental Impact Assessment) Regulations 2017 (the EIA Regulations). This means we have a legal duty to carry out a full environmental impact assessment which will be made available at 

At our statutory consultation in 2023 we will present a Preliminary Environmental Information Report (PEIR) summarising the likely impacts and potential mitigation measures. Stakeholders will have the opportunity to comment on the PEIR and make relevant representations to the Examining Authority (Planning Inspectorate - PINS) and members of the public are able to comment via the feedback process during consultation.  

In 2024, the full Environmental Statement (ES) will be submitted with the DCO application.  

To date, we have submitted the scoping report to the Examining Authority and have received their opinion.  Our environmental specialists are currently reviewing the response to be able to proceed and produce the PEIR.  All scoping documentation is available on the PINS website here.

I think my land is impacted by your proposals, what should I do?

If you feel your land may be affected by these proposals, please contact the Sea Link Land Team by emailing [email protected]

Alternatively, you can write to 1 Staplehurst Farm, Weston on the Green, Oxfordshire, OX25 3QU. 


Why use high voltage direct current?

Subject to the need of the project, HVDC can be the most efficient way of transporting electricity over long distances. The direction the electricity flows can be controlled, which will become particularly important as we manage intermittent renewable energy.

What is a converter station?

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

Why is the converter station being sited within a given distance from the existing network?

Siting the converter station as close to the transmission network as possible reduces the amount of equipment needed to transmit AC electricity. The greater the distance, the greater the cost to consumers and impact on communities and the environment.

If you co-locate 3 converter stations together how big a footprint would that take up? How many football pitches is that?

Each Converter Station will be approximately 6 hectares, therefore a site for 3 converters would cover around 18 hectares.

1 Hectare is approximately 1.2 to 1.6 football pitches therefore the whole site will cover approximately 28 football pitches.

Why can’t you build the infrastructure offshore, create an offshore grid with one connection point?

National Grid Electricity Transmission (Sea Link), National Grid Ventures (Nautilus and EuroLink), North Falls (offshore wind farm) and Five Estuaries (offshore wind farm) are working together as part of the Offshore Transmission Network Review (OTNR) “Early Opportunities” workstream, with a view to identifying a future Pathfinder Project. More information can be found here.

This group is exploring several options, one of which is to connect offshore wind into Sea Link at a location near the wind farms via an offshore platform mounted high voltage direct current converter. The onshore proposals for Sea Link would remain unchanged, with connections at the proposed Friston substation in Suffolk and in the Richborough area in Kent, as any offshore infrastructure would not remove the need for the onshore infrastructure.  

This offshore coordination review is ongoing, and at this stage there is no guarantee that Sea Link can be or will be used as means of connecting wind generation offshore. Ultimately, Sea Link remains a network reinforcement project and it must meet this need, as defined in the Network Options Assessment.   

Sea Link

Contact us

Please get in touch if you have any questions or comments about Sea Link by emailing [email protected] or calling us on 0808 134 9569.

You can also write to us at FREEPOST SEA LINK, please note no stamp or further address details are required.

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