Mendip Hills

Overview – Summer 2022

National Grid’s contractor, Balfour Beatty, has connected the new high voltage 400kV underground cables through the Mendip Hills in the Area of Outstanding Natural Beauty (AONB) to the new overhead line at Loxton.

In July 2022, we removed the temporary scaffolding at Loxton cable sealing end compound erected to create a sterile environment for specialist engineers to connect the new underground cables to the new line of T-pylons that will help carry low carbon energy to six million homes and businesses.

The next step for the cabling team is to finish jointing and testing the cables, ahead of their energisation in October 2022.

We’re pleased to be putting 8.5 kilometres of the Hinkley Connection route underground through this very special landscape of the Mendip Hills in response to community feedback received during consultation. By doing so, we are leaving this part of the Area of Outstanding Beauty free of pylons for the first time in 91 years.

28 existing pylons between Loxton and Sandford will be removed by summer 2022 with the eight closest to Sandford substation programmed for removal next year, bringing us another step closer to removing 67 kilometres of overhead line by the time the Hinkley Connection Project is completed in 2025.

Thank you from everyone working on the project for your patience as we continue our work to deliver electricity safely, efficiently, and reliably, and support the UK’s ambition to achieve net zero by 2050.

Contact our community relations team to register for project updates direct to your inbox.

Take a look at our detailed map

Mendip Hills timeline

Early 2019 to early 2024


Build Mendip Hills 400,000 volt underground cable

Work started in this area in April 2019.

What we're doing:

  • Advance landscaping and planting around the location of the new cable sealing end (CSE) compound.

  • Building temporary entrances and access roads to allow construction traffic to enter site from the local highway. You can find more information on our construction information page.

  • Installing a temporary site office and temporary construction compound north of Tarnock, and up to four secondary temporary construction compounds along the route to minimise traffic movements on site. One of these secondary compounds will be located immediately south of the new CSE compound.

  • Constructing a new CSE compound east of the M5 motorway to the south of the Mendip Hills Area of Outstanding Natural Beauty (AONB) and the River Axe.

  • Laying 8.5 km of 400,000 volt underground cables from the CSE compound south of the Mendip Hills AONB northwards to the new Sandford substation.

Mid 2021 to mid 2022


Remove existing 132,000 volt overhead line

What we're doing:

  • Removing Western Power Distribution’s overhead line from Bridgwater Substation to the A368 in Sandford. This will make way for, and minimise the visual impact of the new overhead line.