Wedoany.com Report-Mar 12, The first of three new high-voltage electricity cables connecting Dinorwig pumped storage hydroelectric power station in Gwynedd, Wales, to the National Grid has been switched on. The upgrade is part of the Dinorwig to Pentir project, replacing aging cables installed in the 1970s.
Engineers from National Grid, along with contractors Morgan Sindall Infrastructure and Siemens Energy, achieved the milestone as part of ongoing work to maintain a reliable electricity transmission network. Dinorwig power station is owned and operated by First Hydro, which is 75% owned by ENGIE.
Since autumn 2021, National Grid has been upgrading the 12km connection between its 400kV Dinorwig substation, located inside the mountain alongside the power station, and the 400kV Pentir substation. The first new circuit consists of three 12.2km cables, each made from 14 sections joined together, with a total weight of approximately 1,500 tonnes. The cables run under sections of the A4086 and A4244, across nearby fields, and within Dinorwig itself.
The new circuits take a different route from the original cables, allowing the existing infrastructure to remain in service and continue transmitting power while upgrades are completed. Work is ongoing to install two additional circuits as part of the project.
Phil Rose, National Grid’s Lead Project Manager for the cable replacement, said: “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. It’s also a fantastic achievement for the team despite some very difficult conditions, with extremely hard rock and unprecedented rainfall challenging our progress at times. We appreciate the cooperation and understanding of the local community whilst the work takes place, and want to thank everyone locally for their continued patience while this essential work progresses.”
Peter Kirk, Managing Director – Energy at Morgan Sindall Infrastructure, added: “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.”
“As owner and operator of Dinorwig power station, ENGIE is excited to see the first new high-voltage cables energised as part of the Dinorwig to Pentir project,” commented Delphine Cherel-Sparham, Managing Director of ENGIE Flexible Generation UK. “This milestone is key to futureproofing our infrastructure and ensuring that the clean energy from Dinorwig continues to power communities across the UK.”
Alongside the cable upgrades, National Grid is making progress on major enhancements to its Dinorwig substation. The work, largely hidden from view within the mountain, is a critical component in ensuring a secure connection between the power station and the electricity grid.
Environmental considerations have also been a factor in the project. National Grid has implemented measures to protect bat habitats in Dinorwig’s cable tunnels, including the installation of permanent acoustic barriers to minimize disruption during construction.
Dinorwig hydroelectric power station, located within 16km of underground tunnels beneath Elidir Fawr mountain, plays a key role in the UK’s electricity network. It provides rapid-response power generation to help stabilize electricity demand in Wales and England.
