Electricity interconnectors are subsea cables that connect Great Britain’s electricity grid to those of neighbouring countries, enabling the cross-border flow of electricity. Great Britain currently has ten such interconnectors, connecting us to Norway, Denmark, the Netherlands, Belgium, France, Northern Ireland, and the Republic of Ireland, providing a total operational capacity of 10.3GW. An additional 1.4GW of interconnector capacity to Germany is under construction and a further 6.05GW of interconnection projects are in development following regulatory approval from Ofgem in 2024.
Figure 1: Map of operational and in construction interconnectors to Great Britain
Source: Internal DESNZ representation
Figure 1 description: a map of the UK and neighbouring countries with GB interconnectors.
Interconnection plays a vital role in the electricity system, strengthening our energy security and helping deliver affordable electricity to consumers. In the year to September 2025, we imported 43TWh of electricity, equivalent to 13% of gross UK electricity supply.This helped reduce reliance on more expensive fossil fuel generation in Great Britain and lower overall system costs. In the same period, the UK exported 12TWh of electricity, enabling the productive use of surplus renewable generation.
As part of Great Britain’s Clean Energy Superpower Mission, we expect to further grow our interconnector fleet with additional projects that will enhance our energy security, support European decarbonisation, provide flexibility for the system and facilitate the export of any surplus renewable electricity.
Our existing interconnectors are all ‘point‑to‑point’ links, but in the future, we also want to support Offshore Hybrid Assets (OHAs), an emerging and innovative form of interconnection that combines the interconnector with an offshore wind farm. OHAs can be either Multi-Purpose Interconnectors (MPIs), in which the connected offshore wind farm is in Great Britain’s waters or Non-Standard Interconnectors (NSIs), in which the offshore wind farm is in the connecting country’s waters.
Great Britain is playing a leading role in the development of OHAs. Two NSIs already have initial regulatory approval from Ofgem, and Government, Ofgem and the National Energy System Operator (NESO) are actively developing an innovative policy framework for MPIs. These types of assets are increasingly recognised as the future for North Sea energy infrastructure, as reflected in the shared ambition to deliver 100GW of ‘cooperation projects’ (such as OHAs) by 2050, set out in the Hamburg Declaration of Energy Ministers at the last North Sea Summit.
Figure 2: Multi-Purpose and Non-Standard interconnectors diagram
Source: Internal DESNZ representation
Figure 2 description: On the left a diagram of a multi purpose interconnector, showing a connected wind farm in GB waters. On the right, a diagram of a multi purpose interconnector, showing a connected wind farm not in GB waters.
In the Clean Flexibility Roadmap (2025), we set out how Government, NESO and Ofgem will ensure new interconnection, including OHAs, plays an optimal role within the energy system and maximises benefits for Great Britain’s consumers.
The Government has three strategic objectives for the future of interconnection in Great Britain, to ensure that interconnectors serve the needs of consumers and the energy system:
This publication provides a framework for achieving these goals and is the first step in an ongoing programme that will evolve alongside NESO’s Strategic Energy Planning and Ofgem’s delivery programme. It sets out the context, intentions, and next steps to support the future of interconnection and is being published alongside Ofgem’s Call for Input on the future delivery and financing models.
Read full policy paper below.
Source: UK Government: https://www.gov.uk/government/publications/next-steps-for-electricity-interconnection-in-great-britain
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