The first of three new power cable circuits connecting the Dinorwig hydroelectric power station in north Wales to the UK’s transmission network has been successfully energised. This marks a significant step in the ongoing Dinorwig to Pentir cable replacement project, which aims to replace cables installed in the 1970s that are nearing the end of their operational life.
Engineers from National Grid, alongside contractors Morgan Sindall Infrastructure and Siemens Energy, reached the milestone as part of the wider £300 million upgrade effort. The project involves replacing the 12 km connection between National Grid’s Dinorwig substation and the Pentir substation, both crucial nodes in the transmission network.
Phil Rose, National Grid’s Lead Project Manager for the Dinorwig to Pentir cable replacement project, commented on the achievement: “Completing the first of our three connections marks a really significant milestone in this crucial project to futureproof the infrastructure carrying clean power from Electric Mountain.”
The newly energised circuit, comprising three 12.2 km cables each made from 14 sections and weighing approximately 1,500 tonnes, has been installed underground across various routes, including sections of the A4086 and A4244. Each new circuit takes a separate route from the original cables, allowing the existing connection to remain active during the upgrades and ensuring uninterrupted transmission of renewable power.
The new cables are a key component of National Grid’s effort to enhance grid resilience, enabling better handling of power demand fluctuations and outages. This infrastructure upgrade also aligns with the UK’s efforts to support renewable energy generation and meet its net zero carbon goals.
Peter Kirk, Managing Director of Energy at Morgan Sindall Infrastructure, emphasized the long-term benefits: “Energising circuit 3 at Dinorwig-Pentir creates a more resilient power network for the UK. This improvement will enable the network to better handle sudden changes in power demand and unexpected outages, and also supports the UK’s net zero carbon goals by providing vital infrastructure needed for renewable energy sources.”
The upgrade project is ongoing, with National Grid also making significant progress on the modernization of the Dinorwig substation.
