What does the project involve?
The Green GEN Towy Usk proposal is for a new 132kV (132,000- volt) double-circuit overhead line, supported on steel pylons, between a substation on the Nant Mithil Energy Park in the Radnor Forest area and a new substation, to be developed by National Grid, on the existing 400kV (400,000-volt) transmission line near Llandyfaelog, between Carmarthen and Pont Abraham.
When drawing up our plans, we compared the environmental, technical and cost implications of 11 potential connection options. Following this work, connecting the Nant Mithil Energy Park to the national grid in the Carmarthen area was determined to be the most appropriate solution to take forward for more detailed routeing studies and consultation.
Why is this project needed?
Green GEN Towy Usk will link Bute Energy’s Nant Mithil Energy Park, which will generate around 237MW (megawatts) of clean, green energy in the Radnor Forest area, to the national grid. It will bring clean green energy to the homes and businesses that need it. Importantly, other green energy projects will also be able to connect, reducing the amount of additional infrastructure needed in future.
Green GEN Towy Usk will also allow direct connection of community projects, while reducing pressure on the existing electricity grid, supporting energy resilience, green businesses and enabling green heating and the roll out of electric vehicles across Wales – particularly in rural areas.
What will Green GEN Towy Usk look like?
The new 132kV overhead line will be carried on steel lattice pylons. We need to use steel pylons because there will be two circuits (three sets of wires on each side of the pylons), carrying more power than can be carried safely on a single line of wooden poles. Each pylon will have three arms on each side, and each arm will carry a set of wires – known as conductors.
The standard height for a 132kv pylon is 27m. The average distance between pylons, or ‘span length’, is approximately 250m. Exact pylon heights and span lengths can be increased or decreased depending on the terrain they cross, or obstacles like streams and rivers.
Nant Mithil Energy Park
Nant Mithil Energy Park is located in Powys, Mid-Wales, approximately 9 km east of Llandrindod Wells in Radnor Forest. The Energy Park represents an opportunity to provide clean and renewable energy, using the latest wind turbine and other technology, for the benefit of the local community, the environment and society as a whole.
Nant Mithil is located in an area with an excellent wind resource that can be harnessed to bring benefits in terms of tackling climate change and bringing investment to local communities.
Our preferred route
Working with our environmental consultants, we identified corridors of land through which an overhead line route could be installed, looking at how each might affect local communities, the landscape, local views, biodiversity, forestry and cultural heritage, floor risk and other land uses.
We then selected a preferred corridor for Green GEN Towy Usk and identified potential route options within it. Following further research, we have selected a preferred route in that corridor to take forward for public consultation.
Our preferred route avoids and seeks to reduce potential impacts on the Brecon Beacons National Park and other sensitive landscapes, and required the least amount of new infrastructure.
We believe this route achieves the best balance between our technical requirements and minimising the impact on the environment and the people, who live, work and enjoy spending their time in the area.
We know that new infrastructure can be disruptive to communities. We are committed to doing everything we can to cause the least disturbance to the environment and those who live, work and enjoy recreation close to our proposals.
You can find out more information about how we identified our preferred route, and the other options we considered, in our Routeing and Consultation Document and our Grid Connection Strategy Report.