submarine power cable
A submarine power cable is a transmission cable for carrying electric power below the surface of the water.HVDC
A high-voltage direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway) uses direct current (DC) for electric power transmission, in contrast with the more common alternating curren ...
connector would link
Kingsnorth
Kingsnorth is a mixed rural and urban village and relatively large civil parish adjoining Ashford in Kent, England. The civil parish includes the district of Park Farm.
Features
The Greensand Way, a long distance footpath stretching from Hasl ...
Bourbourg
Bourbourg (; ) is a commune in the Nord department in northern France. It is situated in the maritime plain of northern France, in the middle of a triangle formed by Dunkirk, Calais, and Saint-Omer.
Population
In 1945 Bourbourg absorbed the for ...
(
Nord
Nord, a word meaning "north" in several European languages, may refer to:
Acronyms
* National Organization for Rare Disorders, an American nonprofit organization
* New Orleans Recreation Department, New Orleans, Louisiana, US
Film and televisi ...
) near
Dunkirk
Dunkirk (french: Dunkerque ; vls, label=French Flemish, Duunkerke; nl, Duinkerke(n) ; , ;) is a commune in the department of Nord in northern France.
Background
Electricity interconnectors are high-voltage transmission links, linking two electricity grids. Electricity can flow in both directions, allowing a grid to import electricity when it is running short so it does not have to fire up old, inefficient fossil fuel power stations. Renewable sources are dependent on the time of day and on the weather conditions; the required load can be balanced by interconnecting grids over a large region, in this case over the Northern Seas Offshore Grid, and the North–South Western EU Interconnections.
Current status
On 28 January 2022 the rejected an investment request by Gridlink to operate the interconnector in France citing legal uncertainties and possibly reduced benefits due to
Brexit
Brexit (; a portmanteau of "British exit") was the withdrawal of the United Kingdom (UK) from the European Union (EU) at 23:00 GMT on 31 January 2020 (00:00 1 February 2020 CET).The UK also left the European Atomic Energy Community (EAEC or ...
, stating that "The cost-benefit analysis of the project does not show with sufficient certainty, on average based on the available contrasted scenarios, that the project brings a net benefit to the community."
.
Technical description
The project to build this interconnector comprises
* submarine cable ( in UK waters and in French territorial waters), working at a DC voltage of approximately 525kV.
*Underground cables from the shoreline to the converter station at Kingsnorth and Warande.
*Converter stations in Kingsnorth and Warande where the HVDC voltage is converted to 400kV AC, which is the working voltage of both the networks.
*Underground high-voltage connector cables from the converter stations to the UK and French networks
*An additional substation in France.
Proposed project timescale
The projected timescale is:
:Awarded Project of Common Interest status (PCI) by European Commission 23 November 2017 (Commission Delegated Regulation 2018/540)
:Application for UK development consents September 2020, and in France November 2020.
:Construction contracts to be awarded July 2021, detailed planning consents September 2021.
:Construction starts December 2021
:Commissioning June 2024
:Commercial operations start December 2024
Route
The undersea cable connects two national grids, so must run from locations, close to the coast, capable of injecting the extra 1.4GW of power into the grid. Three points in Northern France were considered
Penly
Penly is a former commune in the Seine-Maritime department in the Normandy region in northern France. On 1 January 2016, it was merged into the new commune of Petit-Caux.Les Attaques
Les Attaques () is a commune in the Pas-de-Calais department in the Hauts-de-France region of France.
Geography
A large farming and light industrial village located 4 miles (6 km) southeast of Calais, at the junction of the N43 and D248 road ...
and Warande. Only Warande had sufficient capacity. On the UK side sites along the south coast were rejected as there was not sufficient infrastructure available to transport the electricity to the main network, while the North Kent coast and the banks of Thames Estuary was well supported. The following seven suitable sites were considered before Kingsnorth was selected: Cleve Hill, Coryton,
Grain
A grain is a small, hard, dry fruit (caryopsis) – with or without an attached hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and legum ...
, Kemsley, Kingsnorth, Northfleet East and Rayleigh Main. The existing Kingsnorth sub-station already had the capacity, as the Kingsnorth coal fired power station had been decommissioned, and was 1.5km (1 mile) from the shore.
The 400kV AC link from the substation at Kingsnorth passes though a 1.5km (1 mile) underground duct to the converter station which is on the shoreline. The two HVDC undersea cables enter a trench under the sea perpendicular to the shore and under the shipping channel where it follows the southern bank until off
Grain
A grain is a small, hard, dry fruit (caryopsis) – with or without an attached hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and legum ...
where it crosses the channel and leaves the
Medway
Medway is a unitary authority district and conurbation in Kent, South East England. It had a population of 278,016 in 2019. The unitary authority was formed in 1998 when Rochester-upon-Medway amalgamated with the Borough of Gillingham to for ...
passing to the north of the Sheppey anchorage berths.
The cable lies on the seabed protected by a covering of rocks or in a trench. Other users must not be disrupted, and a series of hazards must be avoided: anchorages, navigation channels, environmentally sensitive areas, known wrecks, moving sandbanks, unexploded ordnance, windfarms and other subsea cables. The route was chosen to take all this into account, and to turn south on the most western route to minimise cable length. In the Thames, it runs to the south of the Pan Sands sand bank and south of the BritNed interconnector cable.
In France the HVDC cable crosses the coastline in an industrial area owned by the Grand Maritime Port of Dunkerque (GMPD) and passes under their land for to a site alongside the RD11 junction (52a/b) with the
A16 autoroute
The A16 Autoroutes of France, autoroute – also known as ''L'Européenne'' and forming between Abbeville and Dunkirk a part of the larger ''Autoroute des estuaires'' – is a motorway in northern France.
The motorway, which has a total length ...
to the new converter station. The 400kV AC link travels underground to the new Warande substation that is to be built adjacent to the existing RTE Bourbourg substation; they will share connection to the 400kV AC overhead lines of the RTE.