One of the most common questions we are asked is about grid, and how the electricity generated at the proposed Glyn Cothi Wind Farm will connect to the transmission or distribution network.
That’s why we’ve put together this note, to explain how the grid works, and what stage of the process we’re at in terms of making decisions about the way that Glyn Cothi Wind Farm will connect.
How does the electricity grid work?
The electricity grid is an interconnected network of power plants, transmission lines, and distribution systems that delivers electricity to consumers, such as to your house or to a business, factory or industrial location.
This note looks at generation, and how the electricity that is generated gets to where it is needed.
Electricity is produced or generated at power plants. In this example, the power plant is the proposed Glyn Cothi Wind Farm, where the blades on each turbine will capture the kinetic energy of the wind. The generator housed within the nacelle (located at the top of the turbine) converts this into electricity.
Once generated, the electricity has to be delivered to where it is needed.
In the case of Glyn Cothi, the intention is to deliver the electricity locally across the distribution network.
It’s useful to think of the electricity grid in terms of the road network, where motorways link large towns and cities, while smaller road networks (A and B roads) link those towns and cities to smaller settlements and villages. To get from one place to another, we might only need to use the A and B roads for shorter journeys and use the motorway network when we are travelling further afield.
How is the electricity network similar to the road network?
The transmission network is the equivalent of the motorway network. This network carries higher voltage electricity (274kV or 400kV) for long-distance travel across the country, held aloft by large steel towers, or pylons.
The distribution network is the equivalent of the A and B road network. This network carries lower voltage electricity (132kV and below) suitable for local use, held aloft by smaller pylons or wooden pole lines.
What network will be used for the proposed Glyn Cothi Wind Farm?
Electricity generated from Glyn Cothi will connect into the new substation proposed at Llandyfaelog, near Kidwelly via a new wooden pole line, at the distribution level, similar to those in the photo.
As the connection is into the distribution network, the electricity will be consumed locally, when the demand is there.
The connection date that we have currently been given by the network operator is 2036. We have however requested (through the Connections Reform process), an accelerated connection date in the early 2030s. We will update stakeholders when we have further information from the network operator.
Why not underground the cables?
We are often asked why we don’t underground the cables. We are happy to consider undergrounding.
Undergrounding the cables can add significant costs to the project. Undergrounding also has other impacts on the environment, as well as disruption and noise while the trenches are being dug.
The electricity distribution network operator, National Grid Electricity Distribution (NGED) in this case, determine where every new electricity generating plant in their region will connect into the grid. They do this in conjunction with National Grid Electricity Transmission (NGET) and National System Operator (NESO).
For the purposes of our wind farm project Infrastructure Consent (IC) application, Trydan has to satisfy the Planning Inspector that a grid connection is possible. The grid connection offer we have received is a key milestone.
The grid connection won’t form part of Trydan’s application for Infrastructure Consent for Glyn Cothi Wind Farm. Full details of the grid connection, including the route and the detailed planning application, will follow in due course.
To conclude
As things stand, connecting to the local distribution network, via wooden poles, is the approach we are proposing. Trydan will explore other options, should they become available, including the feasibility of undergrounding.