National Grid submits planning applications for vital electricity network upgrade in North Wales to connect cleaner energy to homes and businesses

Following submission in early December of three planning applications to Gwynedd Council and an application to Eryri National Park Authority on proposals to reinforce and refurbish the existing electricity network between Pentir and Trawsfynydd in North Wales, National Grid has received confirmation that all applications have now been validated by the respective Local Planning Authorities.

Planning application validation is the initial check by a local council to ensure a submitted planning application is complete and includes all required documentation and assessments and has been correctly made before being officially processed.

The upgrades are part of The Great Grid Upgrade, a major transformation of the UK’s electricity network. They will help to meet growing energy demand, ease pressure on the current network, support Wales’ clean power and energy security goals, and lower constraint costs - extra costs when grid capacity is insufficient to move power to where it is needed. These upgrades will help boost local economies, create jobs and deliver a more secure network, connecting cleaner energy from more affordable sources to homes and businesses.

John Lamb, Director for Pentir to Trawsfynydd, said: “We are pleased to have reached a significant milestone for our Pentir to Trawsfynydd project.

“We need to reinforce and refurbish the existing electricity network between Pentir and Trawsfynydd to meet rising electricity demand and allow new sources of cleaner, home-grown energy from more affordable sources to reach homes and businesses. This will help to enable a clean energy future for Wales, make our energy supply more secure, independent and deliver long-term benefits to bill payers.”

The planning applications for the four main elements of the project are:   

• Installing new and replacement underground cables and other equipment within the existing substation site at Pentir  
• Replacing 5.8km of underground cables that run beneath the Glaslyn Estuary at Porthmadog from Wern to Minffordd 
• Constructing a new substation south of Bryncir 
• Installing new and replacement underground cables and other equipment within the existing substation site at Trawsfynydd.  

The submission of the planning applications follows a series of public information events National Grid held in May which provided the local community with the opportunity to understand our plans, meet the project team and ask questions. 

In line with Welsh Government requirements, we also held statutory pre-application consultations for 28 days in September. This allowed us to consult on our draft applications and receive comments that have helped refine our plans ahead of submitting our planning applications. 

We anticipate decisions on our planning applications early next year and, subject to the applications being approved, construction will begin in Summer 2026 with the project scheduled to be fully operational in 2030.

To learn more about the proposals visit www.nationalgrid.com/Pentir-Trawsfynydd