What are “Interconnectors”?

 By Nicholas Newman

Interconnectors are key elements in the transmission of energy between separate energy networks and play a vital role in the UK’s ability to meet demand at peak times. Huge amounts of electricity and gas are constantly crisscrossing the seas between Europe and the UK through interconnectors. To transmit electricity, the interconnector comprises a power cable; for gas, a pipeline facilitates the flow between two respective networks…

Subsea interconnectors link the UK’s power network with their French and Dutch counterparts. Likewise, the bi-directional Balgzand to Bacton pipeline carries gas from the Netherlands to the UK to arbitrage price differences and meet variations in peak demand since these differ by exactly one hour between the UK and the continent. Similar electricity and gas interconnectors, crossing land borders or connecting land areas separated by water, are found in Canada, North America and elsewhere in Europe where large-scale capacity upgrades and new gas and power interconnector programs are underway.

Subsea interconnectors link the UK's power network with their French and Dutch counterparts (


By acting as a conduit, passing energy from network to network, interconnectors simultaneously boost energy security and improve the scope for energy trading between countries, thereby moderating prices across borders. Of increasing importance, they may offer access to more sustainable energy sources.

Improve energy security

For power markets struggling to satisfy peak demand, electricity interconnectors can access additional power supplies from surplus networks at the press of a button. Speed and flexibility are the hallmarks of the UK’s interconnectors with France and the Netherlands. David Lavender, Press Officer of the UK’s National Grid identifies another advantage, “interconnectors act as an important balancing tool to improve the stability of the system.” The presence of interconnectors provides assurance against power cuts, even at a time when both Britain and France are phasing out power plants and experiencing delays in construction of new plants. A case in point, is the €10.5bn 1.6 GW Flamanville pressurized reactor power plant in Normandy, which is years behind schedule. Interconnector provision is seen as vital by both countries in topping up power supplies.

Britain, for example, currently has four bi-directional power interconnectors: a 2GW link with France, a 1 GW link to the Netherlands, a 500 MW link to Northern Ireland and a 500 MW link to Ireland. In total, these four interconnectors enable Britain to trade up to 4 GW of power at any time in order to meet up to a daily peak demand in Winter of 60 GW. With the UK’s commitment to lower emissions, it is not surprising that there are plans for an additional 6 GW of interconnector capacity to link up with Ireland, France, Belgium, Netherlands, Denmark, Norway and even Iceland.

For instance, the planned 1-GW interconnector ElecLink, which will connect the UK and France via the Channel Tunnel, is expected to cost €500 million and, on completion in 2019, will offer certainty of additional power. A 1.3 GW North Sea Link power interconnector between the UK and Norway costing €1.5 billion is also under consideration and could be completed by 2021. Overall, at the end of this planned expansion, the UK will be connected to eight country’s networks by as many as 15 subsea interconnectors, plus one onshore 400 kilovolt electricity interconnector planned to link Northern Ireland with Ireland.

Enable energy trading

Electricity interconnectors enable power generators not only to satisfy demand from domestic customers but also to sell to foreign customers, thereby putting downward pressure on wholesale prices. Lavender confirms, the UK’s “interconnectors enable the import of cheaper electricity from other European energy systems.” The UK’s Secretary of State said recently, that the new interconnector projects could save British households up to £12 billion over the next two decades. For North Sea gas producers, interconnectors match supply and demand by facilitating trade and the wholesale movement of gas from Norway to mainland Europe or, via the UK, to North Western Europe.


Uk Interconnectors

Increase access to sustainable sources of power

Interconnectors dedicated to renewable energy will help the UK meet its lower emissions targets. Once Britain’s current interconnector program is completed, the country will be able to export surplus wind power to neighboring countries and import wind power from Denmark using the planned Viking Link. Likewise, the planned North Sea Link will enable the UK to import Norwegian hydropower. As Lavender observes, “interconnectors enable the efficient delivery of renewable energy supplies where they are needed most.” Access to these new sustainable power sources would enable a reduction in standby fossil fuel power plant capacity, for the times when the sun doesn’t shine and the wind doesn’t blow.


In both Europe and North America, some interconnectors are congested from the injection of increasing and fluctuating supplies of renewable power and shale gas, respectively. A prerequisite for the EU single integrated energy market is for all member states to have “electricity interconnection capacity equivalent to 10 percent of their generating capacity” according to Phil Cope, Moody’s Analyst which would cost an estimated €40 billion, according to the European Commission.

The Malta-Italy Interconnector

In common with other energy infrastructure, interconnectors are vulnerable to extreme weather conditions and human activity. In November 2016, Storm Angus damaged four cables of the 2,000 MW high voltage direct current 70 Km (HVDC) Interconnexion France-Angleterre (IFA) interconnector with the loss of half its capacity until completion of repairs at end of February 2017. Similarly, in January 2017, Malta suffered power cuts caused by winter storm damage to the Enemalta’s Ragusa Terminal, Malta’s end of the subsea bi-directional 200 MW Italy-Malta (IM) HVDC Interconnector. At the time of the storm, the IM HVDC Interconnector was meeting 75 percent of Malta’s power needs. It was only when the recently opened gas power plant at Delimara Power Station began to gradually come on line that power was restored.

Despite their vulnerability to congestion caused by increasing supplies of energy, adverse weather and human activity, interconnectors have proved invaluable in matching supply with demand, not only between Canada and north America but also in key areas around Europe.

about the author
Nicholas Newman
Freelance energy journalist and copywriter who regularly writes for AFRELEC, Economist, Energy World, EER, Petroleum Review, PGJ, E&P, Oil Review Africa, Oil Review Middle East. Shale Gas Guide.