What is an interconnector?

IFA2 will be an electricity interconnector. This is a connection between the electricity transmission systems of different countries.

An interconnector allows countries to exchange power, helping to ensure safe, secure and affordable energy supplies. For IFA2 the connection will be made via high voltage subsea cables, passing through French and British waters.


What are converter stations and substations?

Our electricity transmission system operates independently from continental Europe. An interconnector needs converter stations and substations to make it possible to connect these independent transmission systems.

A converter station converts electricity between Alternating Current (AC) and Direct Current (DC). AC is used in each country’s transmission system, while DC is used for sending electricity along the high voltage subsea cables.

A substation is a point of connection to the national electricity network. National Grid Electricity Transmission plc is a separate company, with responsibility for work to connect to the existing national electricity network.

Why are more interconnectors needed?

Changes to energy generation and demand in Great Britain and continental Europe are creating both risks and opportunities for energy users. IFA2 is just one of a number of interconnector projects National Grid is bringing forward to help us address these changing circumstances.

Interconnectors have been a long-established and successful technology in continental Europe. In Great Britain, by contrast, there is a relatively low level of interconnection and building more interconnectors is likely to bring real benefits to the UK electricity consumers.  Analysis undertaken by National Grid suggests that each 1 GW of new interconnector capacity could help to reduce Great Britain’s wholesale power prices by up to 1-2%.  In total 4-5 GW of new links built to mainland Europe could unlock up to £1 billion of benefits to energy consumers.

As well as providing access to cheaper power, interconnection will also help us secure our energy supply. Consumers throughout Europe use electricity in various ways at different times of the day, and interconnection allows electricity to be moved to where it is needed. This is particularly important at times of ‘system stress’, such as a combination of cold weather and unexpected power station shutdowns. 

There are further benefits from interconnection for our impact on the environment. Renewable energy sources such as wind and wave are an increasingly important part of our energy mix. Increasing interconnection allows us to export energy from renewable sources when environmental conditions mean that generation capacity is high.

Go to National Grid website