National Grid is installing 8.5 km of 400,000-volt underground cables under the Mendip Hills for the new Hinkley Point C power station near Burnham-On-Sea.
National Grid’s Hinkley Connection Project will bring low carbon energy from Hinkley Point C to six million homes and businesses and will also allow for more capacity on the network for renewable energy from the South West peninsular.
The underground cables are being placed in four cable trenches, approximately 2m wide, 1.8m deep, and a few metres apart.
The cables link the new cable sealing end compound at Loxton, south of the Mendip Hills Area of Outstanding Natural Beauty, north towards a new substation at Sandford.
National Grid says the soil is being carefully removed and stored, and the bottom of each trench lined with sand.
A spokesman says: “The cables are delivered on huge drums and installed in ducts. The cables are laid in lengths of between 650m and 1km and joined in jointing bays, where a temporary tent is installed to make sure the cables are safely connected in a clean dry environment.”
“The cables are then covered with cement-bound sand and a protective tile cover. The trenches will be carefully filled with the stored soil from excavation, and the land reinstated by December 2023.”
“The cable pull is now more than 60% complete, running at around 15,000-man hours per month having pulled 63,795m since it started in February, with most of the cables expected to be in place by the beginning of 2022.”
The removal of the existing WPD pylons between Bridgwater and Sandford is due to be completed by 2022, leaving this part of the Mendip Hills pylon free for the first time since the 1960’s. The entire Hinkley Connection Project is due to be completed by 2024.
Robbie Griggs, Project Engineer for National Grid, says: “We’re delighted with progress and are really making the most of the better weather during the summer months when the ground conditions are most favourable, it’s great to be playing our part in meeting low carbon energy targets as well as transforming the Mendip Hills for all to enjoy.”
