T-pylons for Hinkley Connection now fully installed

The last of the T-structures’ 232 diamond-shaped insulators – which hold the high-voltage conductors in a diamond ‘earring’ shape – was recently lifted by crane into place on a T-pylon between Yatton and Kenn in North Somerset by National Grid and principal contractor Balfour Beatty.

According to National Grid, the project will enhance the connection for six million homes and businesses to the low carbon energy that will be produced at Hinkley Point C, the UK’s first new nuclear plant for more than 30 years. A key selling point of the Hinkley Connection Project was the new T-pylon, designed to be less obtrusive than traditional lattice pylons.  

"National Grid’s T-pylons are the first new design for overhead electricity lines in over a century and will play a central role in connecting low-carbon energy to millions of people when Hinkley Point C begins generation,” said Roxane Fisher-Redel, senior project manager for National Grid on the Hinkley Connection Project.

"Erecting all the 116 T-pylon structures is a huge milestone and now we look ahead to 2025 and full completion of this project, which will play such a key role in transmitting cleaner, homegrown energy around the UK – enough to power six million homes and businesses."

The new pylons are around one-third shorter than the traditional 400kV pylons that National grid uses for high voltage transmission, as well as being easier to erect. The first T-pylon was constructed in September 2021 near East Huntspill in Somerset , with 47 more pylons installed across the South West in 2022.  

Early 2023 saw the first section of T-pylons energised between Woolavington and Loxton, with the power lines then transferring to an underground cable to preserve the protected landscape of the Mendip Hills Area of Outstanding Natural Beauty (AONB). National Grid says that all the T-pylons will be energised by the end of 2024. Before then, conductors will be hung from the structures and the last of 249 traditional lattice pylons and 67km of overhead wires will be removed from the landscape to make way for the new electricity connection.