Llanfyrnach to St Clears Reinforcement Project

What is the project?

We’re upgrading the electricity network in north Carmarthenshire and west Wales to give you more reliable power. We’ll be installing a new 33kV circuit between St Clears and Llanfyrnach, alongside upgrades at Llanfyrnach Primary Substation.

This project represents approximately £2.86 million of investment and will include:

• A new 33kV circuit of around 13.85km between St Clears and Llanfyrnach, primarily on overhead wooden pole lines
• Installation of a second 33/11kV transformer at Llanfyrnach substation
• Associated upgrades to switchgear and infrastructure at the site

Together, these works will strengthen the local electricity network and support long-term demand across the area.

Why is the project happening?

Demand for electricity in the Llanfyrnach area is growing steadily, driven by new developments and the increasing uptake of low carbon technologies such as electric vehicles, heat pumps and distributed generation like rooftop solar.

The site is currently reliant on a single 33kV supply, reducing resilience when things go wrong. Demand is also forecast to exceed capacity in the coming years.The proposed project provides the most cost-effective, long-term solution to ensure our network keeps up with local growth.

View project map 

Benefits for local people

This project will deliver long term benefits for communities across the Llanfyrnach and St Clears area:

• A more reliable electricity supply: Adding a second circuit and transformer provides resilience, ensuring we can still supply power to your home if one route is unavailable due to outages, like faults or maintenance.
• Capacity for future demand: The reinforcement will increase capacity, supporting future growth in housing, businesses and local services.
• Support for low carbon technologies: The upgraded network will enable further connections for electric vehicle charging, heat pumps and local renewable generation
• Stronger local infrastructure: The project ensures the network can continue to support key community services, including schools and healthcare facilities.

Timeline

• Current stage: Planning, design and engagement with landowners and stakeholders
• Construction: Subject to consents and approvals
• Completion: Expected 2028

How to find out more

We are committed to keeping communities informed and involved throughout the project.

Further updates, including consultation opportunities and route details, will be published here as the project develops.

Customers are also welcome to get in touch with us on 0800 096 3080, or via National Grid’s general enquiry contact form online, if you would like further information about the works.