What are electricity interconnectors?

Electricity interconnectors are high-voltage direct current (HVDC) submarine cable systems that allow electricity to flow between Great Britain and neighbouring countries. They are bidirectional — depending on relative prices and supply conditions, electricity can flow either way.

Interconnectors are a critical part of GB energy security. They allow the UK to import cheap nuclear power from France when it is abundant, export surplus wind power when GB generation exceeds demand, and balance the grid in real time with European neighbours.

GB’s nine interconnectors

IFA 1 — France (2,000 MW)

The original GB–France interconnector, operational since 1986. Runs from Folkestone in Kent to Bonningues-lès-Calais in France under the English Channel. At 2 GW it is the largest single interconnector by capacity. Primarily used to import French nuclear power to GB or export GB wind surplus to France.

IFA 2 — France (1,000 MW)

A second GB–France link, commissioned in 2021. Runs from Chilling in Hampshire to Tourbe in Normandy. Increased the total GB–France interconnection capacity to 3 GW.

ElecLink — France (1,000 MW)

A privately-owned interconnector running through the Channel Tunnel, commissioned in 2022. The only interconnector routed through an existing tunnel rather than a dedicated submarine cable.

BritNed — Netherlands (1,000 MW)

Connecting Isle of Grain in Kent to the Maasvlakte near Rotterdam. Commissioned in 2011. Flow tends to reflect relative wind conditions — when there is surplus wind in either GB or the Netherlands, that country exports to the other.

Nemo Link — Belgium (1,000 MW)

Commissioned in 2019, connecting Richborough in Kent to Zeebrugge in Belgium. Belgium has limited domestic generation, so Nemo frequently imports GB power.

NSL (North Sea Link) — Norway (1,400 MW)

The world’s longest submarine power cable at 720 km, connecting Blyth in Northumberland to Kvilldal in Norway. Commissioned in 2021. The logic is elegant: GB’s variable wind power complements Norway’s dispatchable hydro — when GB wind is high, export to Norway and “charge up” Norwegian reservoirs; when GB needs power, import Norwegian hydro.

Viking Link — Denmark (1,400 MW)

The world’s longest land and sea power cable, running 1,254 km from Bicker Fen in Lincolnshire to Revsing in Denmark. Commissioned in late 2023. Similar rationale to NSL — links GB wind with Scandinavian hydro storage.

Moyle — Northern Ireland (500 MW)

Connects Auchencrosh in Scotland to Ballycronan More in Northern Ireland. Northern Ireland’s electricity market is integrated with the Republic of Ireland under the Single Electricity Market (SEM), so Moyle effectively connects GB to the all-island Irish grid.

East-West (EWIC) — Republic of Ireland (500 MW)

Connects Pembroke in Wales to Rush North Beach near Dublin. Allows direct exchange between GB and the Republic of Ireland, separate from the Moyle route via Northern Ireland.

How do interconnector flows affect electricity prices?

Interconnectors arbitrage price differences between GB and European markets. When GB prices are higher than French prices, electricity flows from France to GB (import). When GB has abundant, cheap wind power and European prices are higher, GB exports. This price arbitrage is one reason the EU electricity market comparison on UK Grid Live is so interesting — the UK wholesale price is directly linked to European market conditions.

Reading the interconnector panel on UK Grid Live

The Interconnectors card in the right column shows each cable with:

• Blue arrows (import): Electricity flowing into GB from that country. Blue dots on the map move from the foreign endpoint towards the UK coast.
• Orange arrows (export): GB exporting electricity to that country. Orange dots move away from the UK coast.
• Utilisation %: The small percentage figure shows what fraction of the cable’s rated capacity is being used.
• Net Import/Export: The large figure at the top is the sum of all nine cables. A positive number means GB is a net importer overall.

Future interconnectors

Several new interconnectors are in development or construction, including a second link to Norway and new connections to Germany and the Netherlands. As offshore wind capacity grows in both GB and the North Sea, interconnection to balance wind variability across larger geographic areas becomes increasingly valuable.