How interconnectors work

Great Britain is an electrical island, but not an isolated one: high-voltage subsea cables - interconnectors - link it to six neighbouring markets. Together they can move around 10 GW, roughly a quarter of typical demand. Is GB importing right now?

The cables

France came first (IFA, 1986) and remains the biggest link alongside IFA2 and the ElecLink cable through the Channel Tunnel. BritNed reaches the Netherlands, Nemo Belgium, and Viking Link Denmark. North Sea Link to Norway plugs GB into Scandinavian hydro - effectively borrowing a giant water battery. Moyle and the East-West links connect to the island of Ireland’s separate system (the reason this site says GB, not UK).

They are high-voltage direct current (HVDC) cables: DC loses less over long subsea distances, and it means the two grids don’t need to be synchronised - converter stations at each end translate between systems that each keep their own 50 Hz heartbeat.

Which way does the power flow?

Price decides. Power flows toward the more expensive market, which is usually the scarcer one. A windy night in GB pushes prices down and the cables export; a still, cold evening pulls imports in from French nuclear or Norwegian hydro. Because each cable follows its own price pair, GB routinely trades both ways at once - importing from France while exporting to Ireland. The convention everywhere on this site: positive megawatts are imports into GB, negative are exports out.

Flows can swing by gigawatts within the hour - watch them live on the dashboard or as animated arcs on the station map.

Are imports good or bad?

Mostly good: trade smooths out weather and demand across a whole continent, and the counterfactual for an import is usually a GB gas plant running harder. The Carbon Intensity API folds an emissions estimate for imports into the national figure. The honest caveats: interconnectors concentrate a lot of capacity in a few assets, and in a continent-wide scarcity event every market wants the same electrons. That is why the mix pages here treat imports as one slice of a diverse diet, not a strategy on their own.