Nemo Link

Nemo Link is a high-voltage direct current (HVDC) interconnector project that connects the electricity grids of the United Kingdom and Belgium. This 1,000 megawatt (MW) submarine power cable stretches 140 kilometers, with 130 kilometers subsea and 10 kilometers onshore, linking Richborough Energy Park in Kent, UK, to Zeebrugge, Belgium.

Project Overview

The Nemo Link is a joint venture between National Grid, the system operator for Great Britain, and Elia, Belgium's transmission system operator. The project began operations on January 31, 2019, marking a significant milestone in cross-border energy transmission. With a capacity of 1,000 MW, it can supply electricity to approximately 500,000 homes.

Technical Specifications

The interconnector utilizes state-of-the-art HVDC technology, specifically Siemens' HVDC Plus system. This technology allows for bi-directional electricity flow, enabling both countries to import and export power as needed. The transmission voltage is +/- 400 kilovolts (kV) DC.

A notable feature of Nemo Link is its use of cross-linked polyethylene (XLPE) cable technology, making it the first subsea HVDC project in the world to employ this advanced insulation method. The cable system was manufactured and supplied by J-Power Systems, a subsidiary of Sumitomo Electric Industries.

Infrastructure

The project involved the construction of converter stations and electricity substations in both countries. These converter stations, built by Siemens, transform high-voltage alternating current (HVAC) into high-voltage direct current (HVDC) and vice versa. The stations use self-commutated voltage source converters in a modular multilevel converter (VSC-MMC) arrangement.

In Belgium, the HVDC 400kV converter station is located on a greenfield site adjacent to the Electrabel power plant within the Herdersbrug industry zone in Bruges, near Zeebrugge. It connects to the Belgian transmission system via the Gezelle substation, part of the Stevin project.

Performance and Impact

Since its inception, Nemo Link has demonstrated exceptional performance. In its first full year of operation, the interconnector was available for power transmission more than 96% of the time, ranking it among the highest-performing assets of its kind globally.

The project has significantly enhanced grid reliability and access to sustainable power generation for both countries. It allows for the efficient sharing of renewable energy resources across borders, supporting the integration of intermittent wind and solar energy into the grid. This capability is crucial for balancing energy systems that rely increasingly on renewable sources.

Innovative Features

Nemo Link introduced an Intraday Capacity product in November 2019, becoming the first channel interconnector to offer hourly nomination gates. This feature allows market participants to balance the grid closer to real-time operations, accounting for unexpected changes in consumption and production.

Economic and Environmental Benefits

The interconnector facilitates cross-border electricity trading, providing additional options and flexibility for the Belgian and UK electricity markets. It plays a vital role in diversifying the electric supply systems of both countries and contributes to the goal of achieving net-zero carbon emissions by 2050.

Construction and Contracts

The project's construction involved several major contractors. Siemens was awarded the contract for building both converter stations, while J-Power Systems supplied the HVDC cable system. DeepOcean was responsible for laying the subsea cable. The combined value of the contracts awarded to Siemens and J-Power Systems in June 2015 was approximately €500 million.

In conclusion, Nemo Link represents a significant advancement in international energy infrastructure, showcasing the potential of HVDC technology in creating a more integrated, efficient, and sustainable European energy market.