National Grid
National Grid has completed the installation of 116 T-pylons in Somerset as it builds out the infrastructure needed to connect Hinkley Point C to the grid.
The project spans about 57km in total between a new substation in Shurton on the Hinkley Point C site and the existing Seabank substation in Avonmouth. The majority is made up of 48.5km of overhead lines, while an 8.5km stretch runs underground through the Mendip Hills Area of Outstanding Natural Beauty.
Once complete, Hinkley Point C will be the UK’s first new nuclear plant in a generation. Its two nuclear reactors are expected to be able to generate enough low-carbon electricity to power around six million UK homes. The project has faced repeated delays, with EDF admitting in January that the first reactor would not be ready to generate until 2029 at the earliest.
Each of the newly-built T-pylons support 12 conductors for a total of 460km of new power lines across the whole route. Their design sees six conductor spans attached to each diamond earring-shaped insulator on either side of the structure, with wires installed in sections of up to a dozen T-pylons at a time.
National Grid
National Grid only started installing the UK’s first T-pylons last year. They are the first major redesign of electricity pylons domestically since 1927 and are around a third shorter than traditional high-voltage pylon design, with a smaller ground footprint.
Steven Haskayne, project director for National Grid, said: “With the T-pylons fully strung, our Hinkley Connection Project is really starting to take shape. It’s a proud moment for all the teams involved, from our National Grid colleagues to our contractors, all of whom have helped us reach this milestone safely and on schedule.
“We’re grateful to all of the local communities we’ve been working alongside for their patience as our project team continues its work, which is moving us closer to a resilient and secure low-carbon energy supply for millions in the region.”
T-pylons make up the majority of the Hinkley Connection Project’s 57km route through Somerset, with shorter sections of traditional lattice pylons at each end of the route at Shurton and Avonmouth – the latter to ensure safe height over the Port of Bristol area.
The energisation last year of an initial section of the route means high-voltage electricity is already flowing through 36 T-pylons, a new National Grid substation at Sandford and the underground cables through the Mendip Hills. All the remaining T-pylons will be energised by the end of 2024.
As part of the project, National Grid is also removing 67km of existing overhead lines and pylons – 249 in total – from the Somerset landscape. Over 30 pylons running parallel to the new underground section in the Mendip Hills are being taken down, which will leave the landscape pylon-free for the first time in nearly a century.
