IFA2 will use a High Voltage Direct Current (HVDC) cable for the connection between Great Britain and France. The electricity must be converted to and from HVDC and the High Voltage Alternating Current (HVAC) used in the domestic electricity transmission systems of Great Britain and France, and this requires a converter station in each country. Cables connect the converter station to a local substation, which transports the electricity onto the domestic network.
In Great Britain, the connection point would be a new substation at an existing National Grid facility off Chilling Lane near Warsash, Hampshire. The connection substation does not form part of National Grid IFA2’s planning application. The proposed converter station is on a site to the north east of Solent Airport at Daedalus.
The HVDC cables linking Great Britain and France will be routed through the Channel and into the Solent to a landfall at Monks Hill Beach, and then around Solent Airport to the Converter Station. HVAC cables will then connect the converter station to the substation at Chilling, routed underground around Solent Airport to the landfall, then subsea to a landfall near Chilling before travelling underground to the substation.
National Grid IFA2 has secured planning permission for the principle of building a new interconnector. This includes outline planning permission for the converter station and new public open space, full planning permission for the underground cables to the converter station, and connecting the converter station to the substation near Chilling, Warsash.
The Marine Management Organisation (MMO) has also granted IFA2 a Marine Licence for the installation of the UK section of the interconnector subsea cables between France and the United Kingdom.
The connection point for IFA2 in France will be at Tourbe 400kV substation in Normandy, where there is also commercially available land for a converter station adjacent to the site.