Nemo Link supplies electricity across borders

Our engineers helped construct Nemo Link, an HVDC interconnector between the UK and Belgium – and one of several new high-voltage transmission links connecting Britain’s electricity grid to the national grids of neighboring countries. Others still under construction include ElecLink, which will run through the Channel Tunnel between Britain and France, and the 767-kilometer Viking Link between the UK and Denmark.   

Nemo Link, the first high-voltage interconnector between Belgium and the UK, went into operation in 2019. Today, it is operated as a joint venture between the UK’s National Grid and Belgium’s Elia Group and can supply 1,000 MW of electricity – enough for up to one million homes. As the power can flow in either direction, it allows both countries to benefit from cross-border electricity trading and a more diverse energy mix.

Ernest Nkusi, our Technical Project Lead based in Germany, and his team designed the link and was responsible for coordinating our international teams of engineers. “Electricity  can  be  used  to  build bridges,” he says, pointing out that Nemo Link is a perfect example of how the importance of reliable energy connects people in all countries.

At each end of the link, our engineers constructed the converter stations — in Herdersbrug in Belgium, and in Richborough, in the south-east of England. These facilities house our state-of-the-art HVDC PLUS technology, which enables the low-loss transmission of electricity through 140 kilometers of subsea and underground cables. 

This is the first interconnector to realize the powerful ±400 kV DC system for HVDC PLUS technology. It is ideal for this kind of application thanks to its low space requirements, high dynamic performance and ability to control the active-reactive power independently.

Construction of the converter stations was carried out simultaneously, with hundreds of people working on both sides on the English Channel. The various partners and teams from Belgium, the UK and Germany needed to work together, including the client and the many subcontractors who perform a wide range of tasks. Mathieu Donche from Elia Group, the Belgian client partner, says: “What I particularly liked from Siemens Energy on this project is that they put the people first.”

On the Belgian side, our Project Lead Tom Clauwaert says the highlight for him was the first energization of the converter station. “Although everything has been checked and double-checked, it is still a nervous moment when you see if it really works.”

As a company, we have a wealth of experience in realizing large-scale projects all over the world. Even so, Nemo Link stands out for its excellent safety record.

Roughly a year into its construction, Nemo Link clocked one million hours worked, with no time lost to injuries. In 2017, the project was awarded the Sword of Honour by the British Safety Council – a prestigious award given only to projects that excel in terms of environment, health and safety standards.

To underline the importance of safety, the “Come Home Safe” campaign invited the children of the workers to create drawings of mommy or daddy working safely on site. The idea behind the campaign was to reinforce a culture of safety. “It makes you reflect on the potential impact of dangerous behavior,” says Tom. “I have a five-year-old, and it really took me by the heart.”

When people in the UK or Belgium switch on the lights or plug in their phones, they may never realize they’re benefiting from infrastructure that transmits power across borders, but this will occur more and more often. Nemo Link is a significant building block in the broader trend: Europe’s electricity market is becoming increasingly integrated.

As interconnectors provide more links between national electricity grids, they offer grid operators more options, boosting stability and security of supply for both countries. They may also make the market more efficient, as excess supply in one country can satisfy demand in another.

Grid stability is becoming more urgent with the growing role of renewable energy. Interconnectors help to even out the intermittent production from renewable resources. Without them, clean energy capacity may go to waste while elsewhere fossil-fuel power is required to make up the difference.

Nemo Link was a highly successful project, and the further integration of Europe’s electricity grids is continuing with even greater ambitions: Viking Link will be one of the world’s longest DC cable interconnectors in HVDC VSC technology.

Scott Williams, our UK Project Lead on Nemo Link and now on Viking Link, spoke of the importance of trust and open communication in order to manage such a complex project successfully – and we are pleased to carry this over to future projects with National Grid.

The UK wants to achieve net-zero carbon emissions by 2050. Other European countries have similarly ambitious targets. To achieve those aims, many sectors of the economy, such as transportation, are shifting from primary, carbon-containing fuels to electric power. To boost security of supply, national grids can support each other thanks to interconnectors like Nemo Link and Viking Link.

“I believe you cannot change the world in one day,” says Tom. “But at least we could start working today on projects which shape the future.”

If you'd like to go in depth and learn more about the people who designed and built Nemo Link, you can watch the full director's cut version of our film right here.