Enabling the flow of power in the south west

Underground cables have been successfully tested just north of Bridgwater

As part of the Hinkley Connection project, modifications of the existing electricity transmission network near Bridgwater have seen 420 metres of overhead conductors undergrounded to enable a new section 400kV power line connecting Hinkley Point with Melksham substation to pass overhead.  Earlier this month, the underground cables were successfully tested ahead of full energisation later this year. 

The works in Horsey require the installation and removal of temporary masts, two new angle towers and the building of two cable sealing end compounds, where overhead electricity lines connect onto the new section of underground cables. 

The testing of the cables involved transmitting electricity at increasing levels of voltage for several minutes until reaching a max voltage of 260KV which is sustained for an hour to ensure the cables can operate safely and effectively. Following this, the cables have passed their initial commissioning stage which is the first step to the cables being officially accepted onto the electricity network, and are now ready for full energisation along with the short section of T-pylons and conductors that run overhead. 

The underground cables connect Hinkley Point to Bridgwater Substation, the overhead section tees into the line between Hinkley Point C and Bridgwater at Horsey to connect Melksham Substation also. These modifications now connect three separate lines of pylons to Hinkley Point C and, once the new power station is generating, will help provide six million homes and businesses with low carbon, homegrown energy across the south west. 

The commissioning of the underground cables is another step towards a supply of low carbon, homegrown energy 

Steven Haskayne Project Director of the Hinkley Connection project said, “The successful testing of the underground cables at Bridgwater is another step towards a resilient and secure supply of low carbon, homegrown energy to millions of homes and businesses across the south west. Thank you to all of the local communities for the patience as our project team continues its work.”