What are electricity interconnectors?

Electricity interconnectors are high-voltage cables that connect the electricity systems of neighbouring countries. They enable excess power, such as that generated from wind and solar farms, to be traded and shared between countries. This ensures renewable energy isn’t wasted and makes for a greener, more efficient power system.

What is an electricity interconnector?

An electricity interconnector runs under the sea, underground or via overhead cabling, to connect the electricity systems of two countries. It allows the trading and sharing of surplus electricity. There are also gas interconnectors, which enable the sharing of natural gas in a similar way.

Interconnector cables being pulled across a beach - used for the National Grid article 'Connecting electricity systems for a greener Britain'

How do electricity interconnectors help make the energy network greener?

Interconnectors allow us to move surplus renewable electricity from where it’s produced to where it’s needed most. For example, with the planned interconnector between the UK and Norway, North Sea Link, when weather conditions mean that supplies from UK wind farms and solar are lower, we’ll be able to draw on carbon-free Norwegian hydro power. Meanwhile, on blustery or very sunny days in Britain, our excess renewable energy can be sent via the interconnector to Norway. Whichever direction the power flows, by sharing it we’re using every spare electron of zero carbon power and reducing waste.

What other benefits do interconnectors have?

Interconnectors import more affordable electricity from Europe, which reduces end-user bills and will save consumers millions of pounds a year by 2024.

By connecting Great Britain to broader and more diverse sources of energy, interconnectors are also contributing to making the electricity system more secure. Interconnectors allow operators to react quickly to swings in supply due to the intermittent nature of renewable energy generation.

How many interconnectors does National Grid have?

As at 2020, National Grid operates three interconnectors, connecting the UK with France, Netherlands and Belgium. Three more are under construction – a second with France, plus one each with Norway and Denmark. Find out more about our interconnectors.

Person holding a section of an interconnector cable

How deep under the sea are interconnectors and how long are they?

Constructing subsea interconnectors is a remarkable feat of engineering – some are in waters that are up to 600 metres deep and they can be hundreds of kilometres long. For instance, North Sea Link, once completed, will stretch 720km between the UK and Norway.

What proportion of Britain’s electricity is sourced via interconnectors?

In 2019, interconnectors supplied 8% (25 TWh) of total electricity consumption in Great Britain, rising to 9% in the first six months of 2020. 66% of this energy in 2019 came from zero-carbon sources.

By 2024 we will be operating at least six interconnectors and 7.8GW of power between Great Britain and Europe. This is enough to supply 25% of our electricity requirements.

What is a multi-purpose interconnector?

Existing ‘point to point’ interconnectors run directly from one location in one country to another, while individual wind farms have to connect one-by-one to the shore. A multi-purpose interconnector will let clusters of wind farms connect directly with the interconnector itself, acting as a green energy hub.

When was the first subsea electricity interconnector built and where?

The first subsea electricity interconnector entered operations in 1961, linking the UK and France. Interconnexion France-Angleterre (IFA), National Grid’s first interconnector, went live in 1986 and also links the UK and France.

Can I see the impact of interconnectors to and from the UK?

Our Power of Now website shows how much CO2 is being saved by using interconnectors to and from the UK at any one time.

Engineering marvels

Engineering marvels under the sea

We’ve been building interconnectors – high-voltage electricity cables deep undersea – to exchange renewable energy with other countries in Europe.

About interconnectors