The two main components of the substation are:-
• A 400kV compound to be constructed, owned and operated by National Grid
• A London Array project compound that will transform the power generated by the offshore wind farm to 400kV, to be constructed, owned and operated by London Array.

An indication of the proposed layout of the substation site is given below.

An access road would be constructed to link the substation to the Seasalter Road. The access road will also link to the existing farm building complex at Cleve Farm providing a new access for on-going agricultural operations.

National Grid Compound
The National Grid compound would consist of:
• An overhead line landing compound, where one circuit of the diverted overhead line will be brought down to two steel lattice gantries, which will be between 12m and 16m in height.
• Switchgear and ancillary equipment, housed in a building of approximate dimensions 35m x 20m x 11m in height. This building will also house auxiliary services such as a workshop area and welfare requirements.

This building, and other similar buildings on the substation site, will be clad in profiled aluminium or steel sheet coloured svelte grey.

Project Compound
The main components of the compounds would be:
• The North Elevation; the 9m tall north facing wall of the onshore substation is both an architectural feature and a security wall preventing access into the main project compound. This feature was the key component of an architectural design prepared by RMJM architects which was intended to simultaneously screen the development from views from the Saxon Shore Way and to make the design more appropriate to the surrounding landscape.
• Up to six transformers, each separated by a ‘fire-wall’ not exceeding 9m in height. The main body of each transformer will be contained within an individual noise enclosure of approximate dimensions 10m x 20m x 6m in height. The enclosures are most likely to be steel clad structures with noise absorbing material on the inner face of the structure. The colour scheme for the cladding of the noise enclosures will be subject to agreement with Swale Borough Council. The transformer oil coolers and switchgear connections will be outside of the noise enclosures.
• An open area for electrical equipment such as the air-cooled reactors, typically about 4.5m high, and switchgear, typically about 5m high.
• An auxiliary services building which will be built in the same style as the National Grid switchgear building.
• Fire deluge pump house and tank.
• Fire deluge pump house and tank. The pump house will be about 3.5m high and the deluge tank about 4.4m high.

Lighting
Permanent light fittings would be installed around the main plant components and along the main east to west internal road for use by maintenance staff. Temporary mobile lighting may also be used in some circumstances. The access road to the site, from the Seasalter Road, would not normally be lit.

Fencing
The substation would require permanent external fencing to a specified security standard for this type of installation. Fencing will typically be about 2.5m high with security features installed above that. Internal fencing will separate the various compounds within the substation. The site will have secuiry arrangements normally associated with National Grid substations.

Colour schemes
Although there would be separate compounds for National Grid and the project, there will be a common approach to colour schemes and design of buildings, the details of which would be agreed with Swale Borough Council.