GridLink studied the possibility of connecting to the 400 kV national grid network along the south and east coast of England. Preliminary feasibility studies indicated that the transport of electricity anywhere on the network along the south coast was likely to be restricted due to the limited capacity of the existing grid system taking into account current and planned electricity production and other interconnectors. The area where the network was expected to have the least constraints affecting electricity transportation was the Thames Estuary near London.
Therefore, seven potential connection points at existing sub-400 kV stations were evaluated in this area: Cleve Hill, Coryton, Grain, Kemsley, Kingsnorth, Northfleet East and Rayleigh Main. Further assessments identified Kingsnorth sub-station as the preferred connection point to the network, where there would be no constraints on the import/export of electricity by GridLink. Subsequently, a grid connection agreement concerning a connection to the Kingsnorth sub-station was signed in October 2016 by NGET and GridLink.
GridLink is responsible for the connection works under the grid connection agreement. The connection to Kingsnorth sub-station will be achieved by the installation of a 1.5 km single-circuit or double-circuit, 400 kV alternating current underground cable from the GridLink converter station to the Kingsnorth sub-station. At the sub-station, new equipment will be installed in an existing spare bay. No extension to the sub-station is required. The underground cable route is located wholly within the former E.on coal-fired power station site, where the cables will be placed primarily under site roads or in a designated services corridor.
The grid connection does not require the construction of any new overhead transmission lines.