Nemo link cable road project

Nemo Link is an electrical subsea interconnector between the UK and Belgium. During its planning and construction phase many new environmentally friendly approaches were taken to keep the environmental impact of Nemo Link as small as possible.

 

Highlights

• Nemo Link was successfully routed around environmentally sensitive areas.
• Elia conducted comprehensive studies to be able to consider all impacts, environmental, commercial and cultural, at an early stage and avoid costly and environmentally invasive measures at a later stage.
• A yearly survey of the seabed will be done throughout the operation of Nemo Link. Changes in the seabed and recovery of impacted habitats will be monitored this way and lessons learned will inform the planning and implementation of future projects.

 

About the practice

Nemo Link is a connection between the electricity transmission systems of the UK and Belgium. It consists of subsea and underground cables connected to a converter station and an electricity substation in each country. While building this connection, special attention was paid to environmental considerations. A feasibility study was carried out to determine the best route – as short as possible to minimise disturbance to the marine biological environment and keep costs low. Part of this study was a seabed survey that gathered information on the seabed type, for both engineering and environmental purposes.

On top of that, mandatory Environmental Impact Assessments were carried out for Belgium and the UK, as well as a voluntary one for France to make sure all relevant environmental information was available for the planning process. The risks and impacts of all technical features of the cables were also carefully assessed to ensure that all risks of impact on the environment and the cable itself could be kept as low as possible. This way, possibly invasive maintenance work at a later stage can be kept to a minimum.

To avoid multiple trenches, and thus a bigger impact on the seabed, the HVDC cables were bundled and the trench that had to be dug for the cable was kept as narrow possible. The trench was only between 0.5 and 1 metres wide employing a technique that was only used in the oil and gas industry before being employed for Nemo Link.

 

Find out more

The Nemo Link interconnector is a joint venture between National Grid Interconnector Holdings Limited, a subsidiary company of the UK’s National Grid Plc, and the Belgian Elia Group.

Organisations involved in building Nemo Link include the Flanders Marine Institute, local political authorities, archeologists and many others.