Eurotunnel opens electricity trade between France and England

Nowadays, on the northern side of the English Channel, the subject of linking the United Kingdom to Europe is a delicate one – but not when it comes to the electricity sector. The interconnector operator ElecLink, wholly owned by the same parent company of the Channel Tunnel concessionaire Eurotunnel, is writing a new chapter in the formation of a single European power market. To connect the two electricity grids between Great Britain and France, they are using one of their two rail tunnels for a 1,000-megawatt high-voltage direct current (HVDC) cable – the first time in Europe that this has been done by a private entity rather than a grid operator.

Seated in his London office, high above the busy Westway motorway, ElecLink’s CEO Steven Moore has had a career working in senior positions in electricity trading on both sides of the Channel, so for him this is a very satisfying project to be directing. “It benefits from structural differences between the two national markets,” he explains. “French nuclear generation will always be cheaper, and the hour time difference means that peaks come at different points in the day.” 

These differences will result in consumers gaining from an estimated €640 million in net social benefits as electricity prices are driven down for the equivalent of 2 million households – and they’ll see none of the construction cost on their monthly bills. “Unlike other interconnector projects, consumers did not underwrite the investment. It’s the first fully privately funded interconnector in Europe, and the first-of-a-kind funding model in France and the UK. That’s not something Brexit will change, whatever form it takes – generation will evolve only gradually.” 

ElecLink will auction the traded power transparently and competitively, with its independence an asset to dual key customers the UK's National Grid and France’s RTE. Some could be on as little as an hourly basis, allowing an immediate, flexible response to the intermittence of wind power, so strengthening the role of that environmentally vital renewable source. “At present, the National Grid pays Scottish wind farms not to generate at times,” Steven says, “but that power will soon be able to be sold on those occasions to France. Interconnections can work to shut down coal.” ElecLink expects to avert 6.1 million tons of carbon emission over its first two decades of a lifespan that could easily be double that.

The European Union (EU) has recognized ElecLink’s contribution to security of supply, the environment and affordability by designating it a “Project of Common Interest” and exempting 800 megawatts from regulation for 25 years. This means that that tranche of capacity can be traded via multiyear contracts, offering long-term guaranteed returns on the €580 million investment. 

The construction is now almost complete, exactly on its three-year schedule, with commercial trading expected to start in 2020. Balfour Beatty in consortium with Prysmian is installing the 51 kilometers of DC cabling in the Tunnel and the underground AC cable system in the UK, while RTE is providing the cabling in France. Siemens Energy has been responsible for the overall system design and the construction of converter stations in Folkstone (UK) and Peuplingues (France) that will bridge the power between the two national grids. ElecLink’s faith in Siemens Energy is shown by a contract that will see Siemens Energy also responsible for the operation and maintenance of these two stations for a decade after they are built – total value of around €355 million. “It makes perfect sense,” Moore explains “Siemens has proven expertise and we can focus on the trading.”

This is the first time that an interconnector cable has been run through a rail tunnel. Siemens Energy Project Director Wolfgang Recker, based in Erlangen, outlines the civil engineering challenges. “The UK side in particular is a very tight compound,” he notes, “where we had to stabilize a potentially sliding hill with piles – the equivalent of 73 Olympic swimming pools filled with concrete – while not disturbing a designated Area of Outstanding Natural Beauty.” Both converter stations use a modular multilevel arrangement (VSC-MMC) to convert AC to DC for the cross-channel link. In contrast to line-commutated converter technology, these power transistors can be switched off so the converters can run independently of the grid voltage, thereby increasing stability.

The work involved fruitful collaboration of the rail expertise of Siemens Mobility Division with the transmission know-how of Siemens Energy Management Division. Steven Moore was impressed by the skilled multinational workforce Siemens Energy was able to deploy. “I remember that the safety bulletins were always in four languages.”

While innovative, there are plenty of benefits to using the rail tunnel. Subsea or buried seafloor cables cause environmental damage as they are laid and can often be cut by ships’ anchors. Moore outlines how difficult it is to respond to problems with them: “Try to find where the break is; find an appropriate repair ship; wait for good weather; hope you are lifting the right section – not easy.” Instead, he has been well pleased with what he views as “an optimal solution” enabled by a company that ElecLink considers “not just a good turnkey builder but a reliable long-term partner.” This UK-Europe link is a very happy one.