Sea Link planning examination closes

The planning examination for National Grid’s Sea Link project has closed, moving the proposed 2GW high-voltage direct current connection between Suffolk and Kent into the next stage of the development consent process.

The Examining Authority must now prepare a recommendation report and submit it to the Secretary of State within three months. National Grid Electricity Transmission needs a Development Consent Order before the project can proceed.

Sea Link is designed as a primarily offshore reinforcement between Suffolk and Kent. The proposed scheme includes a 2GW HVDC cable, converter stations, substations, underground and overhead electricity lines, and associated infrastructure at both ends of the route. In Suffolk, the project is proposed to make landfall between Thorpeness and Aldeburgh. In Kent, plans include converter and substation infrastructure at Minster Marshes in the Stour Valley.

The project forms part of National Grid’s wider Great Grid Upgrade programme, which is intended to increase the capability of the electricity transmission system as more renewable and low-carbon generation connects away from historic demand centres. Sea Link has been designed to move power more efficiently between regions and support the transfer of renewable electricity to homes and businesses across the country.

The examination has also exposed the planning tension around major power infrastructure. Local residents, councillors, environmental organisations, and campaign groups have raised concerns about environmental impacts, protected landscapes, landfall locations, and construction effects. Concerns have included potential habitat loss, sensitive sites, and the physical footprint of converter stations and cable corridors.

That tension is now a central feature of transmission reinforcement. The electrical case for new high-capacity links is strengthened by rising renewable output, growing demand, and the cost of constraints on an ageing grid. The planning case is more complex because converter stations, cable corridors, construction compounds, and landfall works have physical impacts on communities and landscapes. Large grid projects need to satisfy national energy system requirements and local environmental scrutiny.

HVDC links are becoming more prominent in Britain’s grid strategy because they can move large blocks of power over long distances with lower losses and greater controllability than conventional alternating current reinforcement in some applications. Converter stations add cost, footprint, and engineering complexity, but they also allow power flows to be controlled more precisely across constrained parts of the network.

The next stage is procedural rather than construction-led. The Secretary of State will consider the Examining Authority’s recommendation before deciding whether to grant consent. If approved, the project would still require detailed delivery planning, procurement, environmental management, construction sequencing, and interface work with existing substations and transmission assets.

Sea Link reflects a broader shift in UK power infrastructure. Clean generation targets are pushing investment beyond individual wind farms, solar farms, and storage projects into the transfer capacity that allows that generation to be used. Without transmission reinforcement, renewable output can be curtailed, connection queues can lengthen, and balancing costs can rise. With it, the grid can absorb a larger share of variable generation, provided planning, procurement, and construction timelines remain aligned.

Project information is available through National Grid’s Sea Link proposals page.