Editing HVDC Cross-Channel

{{short description|Submarine HVDC interconnector between the UK and France}}
{{Infobox power transmission line
| name                = HVDC Cross-Channel<br />Interconnexion France Angleterre
| photo               = Sellindge Converter Station - geograph.org.uk - 413724.jpg
| caption             = Sellindge Converter Station on the UK side of the interconnector
| map                 = {{maplink |type=line |frame=yes |plain=yes |frame-align=center |zoom=7}}
| map_caption         = Location of Cross-Channel<br />Interconnexion France Angleterre
| country             = [[France]], [[United Kingdom]]
| state               = 
| province            = 
| coordinates         = 
| lat                 = 
| long                = 
| direction           = North-South
| start               = [[Sellindge]], United Kingdom 
| through             = [[English Channel]]
| finish              = [[Bonningues-lès-Calais]], France
| par                 = 
| owner               = 
| partners            = [[National Grid plc]]<br />[[Réseau de Transport d'Électricité]]
| operator            = 
| cable_manufacturer  = [[Alstom]]
| cable_installer     = 
| cable_layer         = 
| substation_manufacturer= [[ASEA]] (160{{nbsp}}MW scheme); [[Alstom]] (2,000{{nbsp}}MW scheme)
| substation_installer= 
| contractors         = 
| construction        = 1985 (2,000{{nbsp}}MW scheme)
| expected            = 
| est                 = 1986 (2,000{{nbsp}}MW scheme)
| decom               = 
| type                = submarine cable
| current_type        = [[HVDC]]
| length_km           = 73
| capacity            = 2,000{{nbsp}}MW
| AC_voltage          = 400{{nbsp}}kV
| DC_voltage          = ±270{{nbsp}}kV
| poles_no            = 4 (2 bipoles)
| circuits_no         = 
}}
The '''HVDC Cross-Channel''' ({{langx|fr|'''Interconnexion France Angleterre IFA 2000'''}}) is the {{convert|73|km|mi|adj=mid|-long}} [[high-voltage direct current]] (HVDC) [[interconnector]] that has operated since 1986 under the [[English Channel]] between the [[Synchronous grid of Continental Europe|continental European grid]] at [[Bonningues-lès-Calais]] and the British [[electricity grid]] at [[Sellindge]]. The cable is also known as '''IFA''',<ref>{{Cite web |title=IFA |url=https://ifa1interconnector.com/ifa/ |website=ifa1interconnector.com |access-date=2025-05-03}}</ref><ref>{{Cite web |title=Interconnector customer portal &#124; National Grid Group |url=https://www.nationalgrid.com/our-businesses/national-grid-ventures/interconnectors-connecting-cleaner-future/interconnector-customer-portal |website=www.nationalgrid.com |access-date=2025-05-03}}</ref> and should not be confused with the new [[IFA-2]], another interconnect with France that is three times as long but only half as powerful.

The current 2,000{{nbsp}}MW link is bi-directional and the countries can import or export depending upon market demands, mostly depending upon weather conditions and availability of renewable energy on the British Isles, and French surplus of nuclear generation or demand for electric heating. It was completed in 1986, and replaced the first cross-Channel link which was a 160{{nbsp}}MW link completed in 1961 and decommissioned in 1984.

A fire in September 2021 caused the link to be removed from service. National Grid announced that half of its capacity would be restored on 20 October 2021, with full capacity being restored by October 2023.<ref name="guardian-20211015" />

== 160 MW system (1961) ==
The first HVDC Cross-Channel scheme was built by [[ASEA]] and went into service in 1961,<ref>Compendium of HVDC schemes, [[International Council on Large Electric Systems|CIGRÉ]], [http://b4.cigre.org/Publications/Other-Documents/Compendium-of-all-HVDC-projects Compendium of all HVDC projects]. {{Webarchive|url=https://web.archive.org/web/20140728130745/http://b4.cigre.org/Publications/Other-Documents/Compendium-of-all-HVDC-projects |date=2014-07-28 }}</ref> between [[HVDC Converter Station|converter stations]] at [[Lydd]] in England (next to [[Dungeness Nuclear Power Station]]) and [[Echinghen]], near [[Boulogne-sur-Mer]], in France. This scheme was equipped with [[mercury-arc valve]]s, each having four [[anode]]s in parallel.<ref>Cory, B.J., Adamson, C., Ainsworth, J.D., Freris, L.L., Funke, B., Harris, L.A., Sykes, J.H.M., High-voltage direct current converters and systems, Macdonald & Co. (publishers) Ltd, 1965, p175–218.</ref>

In order to keep the disturbances of the [[magnetic compass]]es of passing ships as small as possible, a [[High-voltage direct current#Bipolar|bipolar cable]] was used.  The cable had a length of {{convert|65|km|abbr=in}} and was operated symmetrically at a voltage of ±100{{nbsp}}kV and a maximum current of 800{{nbsp}}amperes. The maximum transmission power of this cable was 160{{nbsp}}megawatts (MW). The cable was built by [[ABB]].<ref>{{Cite web |title=60 years of HVDC |url=https://library.e.abb.com/public/7128cd574f8bd332c1257d2000540df1/32-41%202m434_EN_72dpi.pdf |access-date=6 March 2018 |publisher=ABB Group}}</ref> Given that the cable was laid on the surface of the seabed it was prone to being fouled by fishing nets, causing damage. Whilst repairs were undertaken there was considerable down time on the circuit resulting in a loss of trading. Indeed, by 1984 the circuit was disconnected from the Main Transmission System.

== 2,000 MW system (1986) ==
Because the first installation did not meet increasing requirements, it was replaced in 1975–1986 by a new HVDC system with a maximum transmission rating of 2,000{{nbsp}}MW between France and the United Kingdom, for which two new converter stations were built in [[Sellindge]], between [[Ashford, Kent|Ashford]] and [[Folkestone]] in [[Kent]], England and in [[Bonningues-lès-Calais]] (Les Mandarins station), near [[Calais]], France. Unlike most HVDC schemes, where the two converter stations are built by the same manufacturer, the two converter stations of the 2,000{{nbsp}}MW scheme were built by different manufacturers (although both have subsequently become part of the same parent company, [[Alstom]]). The Sellindge converter station was built by [[General Electric Company|GEC]]<ref>Rowe, B.A., Goodrich, F.G., Herbert, I.R., Commissioning the Cross Channel h.v.d.c. link, [[General Electric Company|GEC]] Review, Vol. 3, No. 2, 1987.</ref> and the Les Mandarins converter station was built by CGE Alstom.

This HVDC-link is {{convert|73|km|abbr=in}} long in route, with {{convert|70|km|abbr=in}}  between the two ends.  The undersea section consists of eight {{convert|46|km|abbr=in}} long 270{{nbsp}}kV [[Submarine power cable|submarine cables]], laid between Folkestone (UK) and [[Sangatte]] (France), arranged as two fully independent 1,000{{nbsp}}MW Bipoles, each operated at a DC voltage of ±270{{nbsp}}kV. Cables are laid in pairs in four trenches so that the magnetic fields generated by the two conductors are largely cancelled. The landside parts of the link consist of 8{{nbsp}}cables with lengths of {{convert|18.5|km|abbr=in}} in England, and {{convert|6.35|km|abbr=in}} in France.<ref>Compendium of HVDC schemes, [[International Council on Large Electric Systems|CIGRÉ]] Technical Brochure No. 003, 1987, pp194–199.</ref>

In common with the 1961 scheme, there is no provision to permit neutral current to flow through the sea.  Although each station includes an earth electrode, this is used only to provide a neutral reference, and only one of the two electrodes is connected at a given time so that there can be no current flow between them.

The system was built with solid-state semiconductor [[thyristor valve]]s from the outset. Initially these were air-cooled and used analogue control systems, and in 2011 and 2012 respectively, the thyristor valves of Bipole 1 and Bipole 2 were replaced by modern water-cooled thyristor valves and digital control systems supplied by Alstom.<ref name="areva">{{Cite web |date=2009-12-01 |title=Anglo – French HVDC Link |url=http://www.areva-td.com/solutions/liblocal/docs/Success%20stories/Anglo%20French%20HVDC%20Link%20Cross%20Channel%20Scheme.pdf |url-status=dead |archive-url=https://web.archive.org/web/20140708165537/http://www.areva-td.com/solutions/liblocal/docs/Success%20stories/Anglo%20French%20HVDC%20Link%20Cross%20Channel%20Scheme.pdf |archive-date=July 8, 2014 |access-date=2010-02-28 |publisher=[[Areva]]}}</ref>

This system remains the world's largest-capacity submarine cable HVDC system.<ref>{{Cite web |title=HVDC Submarine Power Cables in the World |url=http://publications.jrc.ec.europa.eu/repository/bitstream/JRC97720/ld-na-27527-en-n.pdf |access-date=6 March 2018 |publisher=Joint Research Centre}}</ref>

In November 2016, during [[Storm Angus]], a ship dragging an anchor cut four of the eight cable components, reducing capacity by 50%.<ref>{{Cite web |date=2 December 2016 |title=How a Loose Anchor Cut Up Britain's Power Link With France |url=https://www.bloomberg.com/news/articles/2016-12-02/how-a-loose-anchor-cut-up-britain-s-power-link-with-france |publisher=[[Bloomberg News]]}}</ref> Repairs were completed by the end of February 2017. The equipment occasionally faults, causing capacity to drop: in a bad year, this might happen several times. To maintain grid frequency and power, the National Grid has a variety of [[Frequency response (electrical grid)|frequency response]] assets, of which [[Battery storage power station|market batteries]] are the first to respond.<ref>{{Cite web |last=Stoker |first=Liam |date=5 June 2019 |title=Batteries act as first responders when UK-France interconnector trips |url=https://www.energy-storage.news/news/batteries-act-as-first-responders-when-uk-france-interconnector-trips |website=Energy Storage News |language=en}}</ref>

In September 2021, a major fire at the Sellindge converter station led to the shutdown of the link.<ref>{{Cite news |date=15 September 2021 |title=National Grid site fire shuts down power cable between France and UK |work=[[BBC News]] |url=https://www.bbc.co.uk/news/uk-england-kent-58570893}}</ref><ref>{{Cite news |last=Ambrose |first=Jillian |date=15 September 2021 |title=Fire shuts one of UK's most important power cables in midst of supply crunch |work=The Guardian |location=London |url=https://www.theguardian.com/business/2021/sep/15/fire-shuts-one-of-uk-most-important-power-cables-in-midst-of-supply-crunch}}</ref> National Grid initially announced that half of the link capacity would be restored within a fortnight, with full capacity being restored in March 2022. The shutdown came at a time of high prices and supply shortage in the UK electricity market, caused by low wind speeds and high prices for natural gas.<ref>{{Cite news |date=16 September 2021 |title=Fire-damaged power link will be out for six months, says National Grid |work=Sky News |url=https://news.sky.com/story/fire-damaged-power-link-will-be-out-for-six-months-says-national-grid-12409414}}</ref><ref>{{Cite web |title=The UK's Energy Price Surge Could be Just Getting Started |url=https://www.poundsterlinglive.com/economics/15947-the-uk-energy-price-surge-could-just-be-getting-started |website=Pound Sterling Live|date=16 September 2021 }}</ref> On 15 October 2021, National Grid announced that half of the link capacity would be restored within the next few days, that 75% capacity would be available between October 2022 and May 2023, and that they hoped to restore full capacity by October 2023.<ref name="guardian-20211015">{{Cite news |last=Ambrose |first=Jillian |date=15 October 2021 |title=Kent's burnt-out electricity cable will take two more years to get back to full service |work=[[The Guardian]] |url=https://www.theguardian.com/business/2021/oct/15/kent-burnt-out-electricity-cable-will-take-two-more-years-to-get-back-to-full-service |access-date=15 October 2021}}</ref>

== Significance ==
Since the commissioning of the 2,000{{nbsp}}MW DC link in the 1980s, the bulk of power flow through the link has been from France to Britain. However, France imports energy as needed during the winter to meet demand, or when there is low availability of hydroelectric power.

{{As of|2005}}, imports of electricity from France have historically accounted for about 5% of electricity available in the UK. Imports through the interconnector have generally been around the highest possible level, given the capacity of the link. In 2006, 97.5% of the energy transfers were made from France to UK, supplying the equivalent of 3{{nbsp}}million English homes. Prior to the 2021 fire, the link availability was around 98%, which was among the best rates in the world. The continued size and duration of the flows are open to some doubt, given the growth in demand in continental Europe for clean electricity, and increasing electricity demand within France.<ref>{{cite web | url=http://webarchive.nationalarchives.gov.uk/tna/+/http://www.dti.gov.uk/files/file11257.pdf/ | title=UK Government Web Archive |website=webarchive.nationalarchives.gov.uk}}</ref>

== Sites ==
{{GeoGroup|section=Sites}}

{| class="wikitable sortable"
 ! Site || Coordinates
|-
| Echingen converter station ||  {{Coord|50|41|48|N|1|38|21|E|type:landmark|name=Cross-Channel ( old) – Echingen Converter Station}}
|-
| Lydd converter station || {{Coord|50|54|54|N|0|56|50|E|type:landmark|name=Cross-Channel ( old) – Lydd Converter Station}}
|-
| Les Mandarins converter station || {{Coord|50|54|11|N|1|47|5|E|type:landmark|name=Cross-Channel ( new) – Les Mandarins Converter Station}}
|-
| [[Sellindge]] converter station || {{Coord|51|6|21|N|0|58|32|E|type:landmark|name=Cross-Channel ( new) – Sellindge Converter Station}}
|}

== See also ==
{{Portal|France|the United Kingdom|Energy}}
* [[IFA-2]], 1,000 MW between the UK and France
* [[ElecLink]], 1,000 MW link between the UK and France through the [[Channel Tunnel]]
* [[BritNed]], 1,000 MW between UK and Netherlands
* [[Nemo Link]], 1,000 MW between UK and Belgium
* [[List of HVDC projects#Europe|List of HVDC projects in Europe]]

== References ==
{{Reflist}}

== External links ==
{{GeoGroup}}
*{{Cite web |title=System Data |url=https://extranet.nationalgrid.com/RealTime |website=National Grid}} live metrics
{{National Grid|state=autocollapse}}
{{Energy in the United Kingdom|sources}}

[[Category:Electrical interconnectors to and from Great Britain]]
[[Category:Electrical interconnectors to and from the Synchronous Grid of Continental Europe]]
[[Category:Energy infrastructure completed in 1961]]
[[Category:Energy infrastructure completed in 1986]]
[[Category:Electric power infrastructure in England]]
[[Category:Electric power infrastructure in France]]
[[Category:HVDC transmission lines]]
[[Category:National Grid (Great Britain)]]
[[Category:France–United Kingdom relations]]
[[Category:1961 establishments in France]]
[[Category:1961 establishments in the United Kingdom]]