We need to build a new converter station close to the existing substation at Westfield, so that AC electricity from the transmission network can be converted to HVDC for safe onward transmission via the underground and subsea cables.
The converter station will be made up of large warehouse-type buildings and outside electrical equipment. The total converter station footprint will be approximately 250m x 350m in size with buildings up to 28.5m in height, to accommodate the equipment needed. We will also need temporary construction and parking areas, and underground cables to connect the converter station to the existing substation. Our plans will include landscaping and tree-planting to help screen the site, reduce its visual effects and increase biodiversity.
Existing converter station at Blyth, Northumberland
Following the first round of public consultation in May 2024, our design team has been carryied detailed site investigations (boreholes and other intrusive surveys) to determine the best location within our preferred site for the converter station, construction compound and earthworks.
These have helped to identify the proposed platform area for buildings and equipment, requirements for the levelling of the site and the best location for the temporary construction compound. Permanent and temporary site accesses from the B9097 have been designed and bunding locations also identified.
Excavated material removed during levelling works will be reused on site where possible, reducing the number of construction vehicle movements. Existing woodland will be retained and additional planting will help to screen the site. We will also create new wetland habitat through drainage works, and look at opportunities for further Biodiversity Net Gain (BNG) on surrounding land.
Westfield is the starting point for EGL4 because it is a strong point on our existing transmission network which is closest to the Fife coast. The Westfield substation is currently a 275kV substation but will be rebuilt in the future as a 400kV substation. We need to have suitable network connectivity at the substation to provide the strongest support for the HVDC link. Westfield substation is the only substation in this area that provides this level of network connectivity and security with four circuit infeeds.