Electricity interconnectors

Electricity interconnectors are the physical links which allow the transfer of electricity across borders.

Interconnectors derive their revenues from congestion revenues. Congestion revenues are dependent on the existence of price differentials between markets at either end of the interconnector. European legislation governs how capacity is allocated. It requires all interconnection capacity to be allocated to the market via market based methods, i.e. auctions. It also includes specific conditions on how revenues are used.

Britain’s electricity market currently has 4GW of interconnector capacity:

  • 2GW to France (IFA)
  • 1GW to the Netherlands (BritNed)
  • 500MW to Northern Ireland (Moyle)
  • 500MW to the Republic of Ireland (East West).

Under the present regulatory regime based on EU and GB requirements, there are two general routes for interconnector investment:

  1. a regulated route under the 'cap and floor' regime. This is a relatively new regime, we decided to roll out the cap and floor regulatory regime to new near-term electricity interconnectors in May 2014.Through the cap and floor approach developers identify, propose and build interconnectors and there is a cap and floor mechanism to regulate how much money a developer can earn once in operation. If applying for a cap and floor regime developers have to comply with all aspects of European legislation on cross border electricity infrastructure. More information about the design of the cap and floor regime can be found in the documents below.
  2. as an alternative to the cap and floor model, developers can still seek exemptions from regulatory requirements. Under this route developers would face the full upside and downside of the investment and would usually apply for an exemption from certain aspects of European legislation in order to increase the safeguards for the business case of their investment.

Existing and future interconnector projects

Below is a list of existing and future interconnectors.

As with other major infrastructure projects future interconnectors face a range of challenges that can impact on timing of delivery. The estimated delivery dates shown below reflects our understanding of developers existing delivery plans for future interconnectors.

PROJECT NAME DEVELOPERS CONNECTING COUNTRY CAPACITY CAP AND FLOOR REGIME? EXEMPTION? DELIVERY DATE/ ESTIMATED DELIVERY DATE
IFA National Grid Interconnector Holdings (NGIH) and RTE France 2000MW No No 1986
Moyle Mutual Energy Ireland 500MW* No No 2002
BritNed NGIH and TenneT Netherlands 1000MW No Yes (Second Package) 2011
EWIC EirGrid Ireland 500MW No No 2012
ElecLink Star Capital Partners Limited and Groupe Eurotunnel France 1000MW No Yes (Third Package) 2019
NEMO NGIH and Elia Belgium 1000MW Yes No 2019
NSN NGIH and Statnett Norway 1400MW Yes No 2020
FAB Link Transmission Investment and RTE France 1400MW Yes No 2022
IFA2 NGIH and RTE France 1000MW Yes No 2020
Viking NGIH and Energinet.dk Denmark 1400MW Yes No 2022
Greenlink Element Power Ireland 500MW Yes No 2021

* Moyle has been operating at around half of its normal 500MW capacity due to subsea cable faults since 2012.

Publications and updates

  • Published: 28th May 2014
  • Factsheets
  • 1 Associated documents
Electricity interconnectors are transmission cables that allow electricity to flow from one country to another. This factsheet explains how they work and how we regulate them in Great Britain.

  • Published: 23rd May 2014
  • Closed: 18th Jul 2014
  • Consultations and responses
  • 21 Associated documents
This consultation sets out our proposal for there to be a new regulatory approach available for investment in new electricity interconnectors. We are proposing to roll out a 'cap and floor' regime to near-term interconnectors.

  • Published: 1st Apr 2014
  • Closed: 29th Apr 2014
  • Consultations and responses
  • 2 Associated documents
This consultation sets out our initial view of efficient costs for the proposed Nemo interconnector between GB and Belgium.

  • Published: 18th Dec 2013
  • Decisions
  • 1 Associated documents
On 24 May 2013 we published an open letter launching a joint review of Interest During Construction (IDC) for offshore transmission and Project NEMO - the proposed GB-Belgium interconnector. 

  • Published: 12th Dec 2013
  • Closed: 13th Feb 2014
  • Consultations and responses
  • 2 Associated documents
This impact assessment outlines the potential impacts of project NEMO, the proposed electricity interconnector between GB and Belgium, being developed.

  • Published: 28th Nov 2013
  • Closed: 3rd Jan 2014
  • Consultations and responses
  • 17 Associated documents
This is a joint consultation by Ofgem and the French regulator, CRE.  It outlines the evidence provided by ElecLink in support of its exemption application for the ElecLink Interconnector.

  • Published: 18th Oct 2013
  • Closed: 15th Nov 2013
  • Consultations and responses
  • 10 Associated documents
This consultation has now closed. We published a decision letter on the 18th December 2013 which explains our decision on the cap on Interest During Construction (IDC) for offshore transmission projects. 

  • Published: 24th May 2013
  • Closed: 21st Jun 2013
  • Consultations and responses
  • 1 Associated documents
Open letter – Offshore electricity transmission and interconnector policy: proposed scope and timetable for review of interest during construction

  • Published: 7th Mar 2013
  • Closed: 3rd May 2013
  • Consultations and responses
  • 20 Associated documents
This consultation presents our proposals for a new regulatory regime for electricity interconnector investment for application to project NEMO, the proposed interconnector between GB and Belgium.

  • Published: 20th Dec 2011
  • Decisions
  • 1 Associated documents
This letter sets out our preliminary conclusions on the cap and floor principles and basic design for NEMO and on development of a GB enduring regulated regime for electricity interconnectors.

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