IFA1 published a General Information update (May 2025) on its official website that made Regional Nomination Platform (RNP v2) resources and Open API documentation available to market participants. The update provided RNP2 OpenAPI specifications and multiple PDF guidance documents (business model kit and nomination APIs) to support participant registration, nomination and interface with TSOs and market platforms (NESO, Elexon, JAO). The release was intended to facilitate operational interactions between market participants and the IFA interconnector's nomination/registration systems.
On 22 December 2023 a fault occurred on the IFA1 HVDC interconnector between France and the UK that caused a full outage of the link. IFA1 comprises two independent bipole cables (each ~1 GW); the link was already operating at half outage when a fault on the second cable tripped the remaining circuit. The fault produced a rapid system frequency disturbance in Great Britain (frequency dropped quickly towards ~49.5 Hz) and led to the loss of around 2 GW of import capacity, contributing to generator trips and system balancing actions. National Grid ESO deployed frequency response and generation resources to restore stability. This event was reported in industry coverage and technical commentary.
On 22 December 2023 the IFA1 fault produced a significant grid constraint on the GB system, removing approximately 2 GW of import capacity and causing a rapid frequency fall that precipitated trips of multiple generators. The resulting constraint required National Grid ESO to call on frequency response services and increase generation in southern England to stabilise system frequency and restore secure operation.
National Grid restored IFA1 to full commercial service (the full 2 GW capacity) on 27 January 2023 following the rebuild and commissioning work to recover equipment damaged by the 2021 converter‑hall fire. The return to full service reinstated the interconnector’s full transmission capability between Sellindge (GB) and Les Mandarins (FR), increasing overall GB interconnector capacity.
National Grid returned the IFA interconnector to full service on 27 January 2023 following a complete rebuild of the IFA converter hall at Sellindge after the September 2021 fire. National Grid reported the converter hall rebuild was completed in around 16 months — substantially faster than normal — with close collaboration with suppliers and a 24/7 shift pattern to restore full capacity and availability.
National Grid completed the rebuild and commissioning work at the Sellindge onshore converter station, returning the IFA interconnector to full 2 GW capacity. Contractor teams carried out installation and commissioning of HVDC valves and associated substation equipment, enabling the onshore station and its AC interfaces to be re-energised and placed back into commercial operation.
As part of the Sellindge converter station rebuild, installation, commissioning and integrated system testing of HVDC equipment and supporting systems — including control, protection and ancillary systems — were completed to validate safe operation and enable full return to service. The testing programme concluded when site systems passed commissioning checks and operational acceptance tests prior to the link operating at full capacity.
Following a major fire at the Sellindge converter station in September 2021, National Grid restored the link to limited service at approximately half capacity (circa 1 GW) as an intermediate energisation and trial operation while repair and rebuild works continued. This partial return to service provided constrained interconnector capability ahead of full repair and allowed limited cross‑Channel flows during the restoration programme.
In 2021 a fire occurred at the IFA1 terminal which materially reduced the interconnector’s availability. Government and market reviews later cited the terminal fire as an example of a high-impact, low-probability event that affected interconnector performance and capacity-market availability assessments.
RTE and National Grid submitted and published the IFA Border-Specific Annex to the Harmonised Allocation Rules (the TSOs' proposal) on 13 April 2017. The document defined allocation and nomination arrangements for the France–England IFA border (including Long Term Transmission Rights), set rules for curtailment, invoicing and collateral, and amended aspects of the IFA Access Rules to reflect IFA-specific operational and market procedures. The publication constituted a formal TSOs' filing/proposal to apply harmonised allocation rules to the IFA interconnector and provided the regulatory and operational framework for capacity allocation and related TSO processes at the IFA border.
| United Kingdom | France | |
|---|---|---|
| Landfall | Monks Hill Beach (southern end of Solent Airfield / Daedalus), near Portsmouth, Hampshire, UK | Landfall east of Merville‑Franceville‑Plage (near Caen), Normandy, France |
| Grid Connection | Sellindge converter station (Sellindge, GB) | Les Mandarins converter station (Les Mandarins, FR) |
United Kingdom
France