Llandyfaelog 132kV Substation
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We are currently developing proposals for a new 132 kilovoltage (kV) substation and associated connecting infrastructure near Llandyfaelog, south of Carmarthen.
Our proposed upgrades are designed to reinforce the existing 132 kV line between Carmarthen and Swansea, supporting the growth in electricity demand in Carmarthen and the wider county, which is currently fed from the Swansea North substation.
The electricity distribution network is undergoing a fundamental transformation as the nature of demand and generation changes. We are seeing a rapid increase in the number of connections associated with small scale renewables (wind and solar), and the electrification of heat (heat pumps) and transport (Electric Vehicles), with demand for electricity set to double nationally by 2050. This places even greater importance on having a resilient distribution network that is fit for future electricity demand.
Who is National Grid Electricity Distribution (NGED)?
National Grid Electricity Distribution (NGED) is one of four separate legal entities that form National Grid in the UK. We own and operate the electricity distribution network for South and West Wales, the Midlands, and South West of England.
We are your local distribution network operator (DNO) and have a legal obligation to connect both electricity demand and generation to our network. We take power from the transmission network operated by National Grid Electricity Transmission (NGET) and distribute it across our system to be converted to a lower voltage for safe distribution to homes and businesses.
As part of our service providing power to over 2 million customers in South and West Wales, we are investing £1.2 billion over 2023 – 2028 to maintain, reinforce and upgrade the electricity distribution network to secure a reliable power supply and a resilient grid.
What are we proposing?
Our planning application is for the construction and operation of a 132 kV substation and associated connecting infrastructure.
The NGET planning application includes the provision of a level platform for all three proposed substations. Elements relating to access, landscaping, and drainage are being taken forward as part of NGET’s application for a 400 kV substation on the same site.
Co-locating our substations minimises the need for new overhead lines on both of the National Grid-owned transmission and distribution networks.
Our planning application will be submitted to Carmarthenshire County Council in summer 2026.
Why is it needed?
Our proposed upgrades are designed to reinforce the existing 132kV network between Carmarthen and Swansea, supporting the growth in electricity demand in Carmarthen and the wider county, which are currently fed from the Swansea North substation.
We are doing this to improve the resilience and capacity of the local distribution network, with aims to meet the forecasted increases in demand that come with housing development, business activity, and the uptake in clean technologies in the area.
Where is the site of the proposed substation?
Our new substation will be located around 6km south of Carmarthen. Site access is proposed to be from a new access road which will connect to the A484.
Our proposals, while separate from NGET’s application for a new 400 kV substation, will sit within the footprint of the NGET site, meaning there will be no increase in the land proposed for new grid infrastructure as a result of our application.
The NGET planning application includes the provision of a level platform for both the 400 kV and 132 kV substations. By combining all ground works into one application, we will ensure more efficient land use, effective drainage and reduced construction impacts for the three substations. We will be working closely with NGET throughout to minimise the impact on the local community.
Any future new connections to the Llandyfaelog substation site will be subject to the appropriate consenting regimes and determined by the relevant authorities at the time.
This decision-making process for future connection is undertaken by the relevant authorities, rather than NGET and NGED as network operators, with each planning application assessed on its own individual merits.
How does this differ from NGET's proposals?
You may be aware that NGET consulted with local communities near Llandyfaelog in 2025 on its proposals for a new 400kV substation.
NGET owns and maintains the electricity transmission network in England and Wales and has a legal obligation to connect customers to the network when a connection is requested. When existing substations do not have the capacity for the size of the connection required, NGET is required to build a new one to meet the need.
NGET is moving forward with plans for a 400kV substation in response to connection requests for two 132kV substations from Green GEN Cymru and NGED respectively. The NGET substation enables NGED, as the distribution network operator, to make corresponding upgrades to the local 132 kV distribution network.
NGED’s proposals form an important next step in delivering the grid upgrades needed to provide our customers with a safe, stable, and reliable electricity supply for homes and businesses in the future.
What are substations and how do they work?
Substations are critical parts of the transmission and distribution networks and enable electricity to be moved about the network at different voltages, securely and reliably.
One of the main roles of a substation is converting electricity into different voltages. This is needed so the electricity can be transmitted across the country at high voltages, and then sent at lower voltages to the end customer on the local distribution network.
NGET takes electricity generated from large power sources, like offshore wind, nuclear and gas power stations, and transports it through its network of overhead lines, cables, and substations.
As the Distribution Network Operator (DNO) for South and West Wales, NGED takes the power from the transmission network, lowers the voltage of the electricity through our substations and send it to end users across the distribution network. NGED also connects smaller scale generation, such as onshore solar, wind, and community energy.
How can communities have their say?
We are conscious that local communities and representatives have been consulted on a number of projects in the area in recent months. However, as NGED is a separate regulated entity from NGET, it is important we understand all potential concerns and opportunities from the community first hand.
We commenced early engagement with stakeholders and the local community in January 2026 with the following in-person and virtual events:
- Thursday 29 January, 3.00pm – 7.00pm - at Llandyfaelog Community Hall, Llandyfaelog, SA17 5PA.
- Saturday 31 January, 11.00am – 3.00pm at Llandyfaelog Community Hall, Llandyfaelog, SA17 5PA.
- Wednesday 4 February, 6.30pm – 8.00pm webinar (register and link available on our website).
We will hold our Pre-Application Consultation (PAC) in late spring at which point there will be an opportunity to submit feedback on our proposals.
Document Library
Here you can find copies of the proposed application, the plans, and other supporting documents.
- Early engagement banners (English)
- Proposed Site Plan (English)
- Early engagement banners (Cymraeg)
What happens next?
We will hold our Pre-Application Consultation (PAC) in late spring 2026.
We are continuing our discussions with landowners and undertake surveys, technical and environmental work in and around the proposed substation site to give us more information about the area and to help inform our plans. You may see us, and our contractors, working in and around the proposed site.
We intend to submit our planning application to Carmarthenshire County Council in summer 2026.
How can I keep informed about the proposed NGED substation?
You can register your interest here to receive project updates about the proposed NGED Llandyfaelog substation.
If you have any questions about the proposed NGED Llandyfaelog substation, you can also get in touch with our community relations team via:
Email: ngedllandyfaelog@nationalgrid.com
Tel: 0800 1884 484