Gridlink Interconnector
| Gridlink | |
|---|---|
| Location | |
| Country | United Kingdom, France |
| Coordinates | 51°25′13″N 0°36′47″E / 51.4204°N 0.6131°E 50°57′42″N 2°11′35″E / 50.9617°N 2.1931°E |
| General direction | west-east, northwest–southeast |
| From | Kingsnorth, Kent |
| Passes through | English |
| To | Warande, Nord |
| Construction information | |
| Commissioned | 2025 |
| Technical information | |
| Type | submarine cable |
| Type of current | HVDC |
| Total length | 140 km (87 mi) |
| Power rating | 1,400 MW |
| AC voltage | 440kV |
| DC voltage | 525 kV |
Gridlink Interconnector is a proposed 1400 MW HVDC subsea electricity connector linking Kihgsnorth National Grid substation in north Kent with RTE Warande substation in Bourbourg (Nord) near Dunkerque in northern France.[1]
Description
Electricity interconnectors are high voltage transmission link, 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 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. [2]
The project to build this 1400 megawatt (1.4GW interconnector) comprises of
- 140 km submarine cable (108km in UK waters and 32km in French territorial waters) working at a DC voltage of approximately 525 kV.
- Underground cables from the shoreline to the convertor station at Kingsnorth and Warande.
- Convertor 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 convertor stations to the UK and French networks
- An additional substation in France.[2]: 3
The Projected Timescale is:
- Awarded Project of Common Interest status (PCI) by European Commission 23 November 2017 (Comission 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[2]: 5
Route
The undersea cable connects two national grids, so must run from locations, close to the coast, capable of injecting the extra 1.4 Gigawatts of power into the grid. Three points in Northern France were considered Penly, Les Attaques and Warande. Only Warande had sufficient capacity. On the UK side sites along the south coast were rejected as there wasn't sufficienct 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, 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 from the shore.[2]: 10
The 400kV AC link from the substation at Kingsnorth passes though an 1.5km 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 where it crosses the channel and leaves the Medway passing to the north of the Sheppey anchorage berths.[2]: 12
The 140km cable lies on the seabed protected by a covering of rocks or in a trench so shallow but not too shallow water is desirable, 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 ordinance, 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.[2]: 14
In France the HVDC cable crosses the coast line in an industrial area owned by the Grand Maritime Port of Dunkerque (GMPD) and passes under their land for 10km to a site alongside the RD11 junction (52a/b) with the A16 autoroute to the new converter station. The 400kV AC link travels 3km underground to the new Warande substation that is to be build adjacent to the existing RTE Bourbourg substation; they will share connection to the 400kV AC overhead lines of the RTE. [2]: 15
References
- ^ Leclere, Matt (28 August 2020). "Plans for massive electricity cable to link Kent and France". Kent Online. Retrieved 10 September 2020.
- ^ a b c d e f g "Gridlink Interconnector Non-Technical Summary" (2). 25 East St, Bromley BR1 1QE: GridLink Interconnector Ltd. August 2020.
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