A new substation (now called ‘Overton substation’) would be required to convert the voltages from the two existing overhead lines – Norton to Osbaldwick (400kV) to the north and Poppleton to Monk Fryston (275kV) to the south. The new section of 400kV YN overhead line would also connect into Overton substation.
Overton substation would contain the necessary equipment to change the voltage between 400kV and 275kV, and would have the following characteristics:
approximate footprint of 82,000m2 (8.2 hectares);
six gantries (two for each overhead line) where each overhead line connects into the substation;
maximum height of 15m at its highest point (including the gantries);
underground cabling within the substation to connect one of the circuits from the overhead lines into Overton substation;
contain four Super Grid Transformers (SGT) to help convert the voltage of the overhead lines (275kV) to connect into the substation; and
palisade electric fence to enclose the site.