Mendip Hills

Overview – Spring 2024

The new 8.5 kilometres of 400,000 volt underground cables under the Mendip Hills Area of Outstanding Natural Beauty are now energised and transporting electricity around the National Grid electricity network

Reinstatement of the land is underway and is continuing across the new connection route. 

We are pleased 8.5 kilometres of the Hinkley Connection route was able to be put 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 Natural Beauty free of pylons for the first time in almost 100 years.

Thank you from everyone working on the project for your patience and understanding as we progress with this vital work to connect six million homes and businesses to new sources of homegrown, low carbon energy, and help the UK meet its net zero ambitions.

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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.

Completed mid 2022


Removal of existing 132,000 volt overhead line

This work has been completed. 

Work carried out:

  • Removed existing overhead line from Bridgwater Substation to the A368 in Sandford. This made way for, and minimised the visual impact of the new overhead line.