The project involves replacing about 44km of existing 132kV overhead lines, which are all supported on steel towers at the moment. These are:
| 1. Polquhanity (3km north of Kendoon) to Kendoon. |
| This will involve building a new 132kV double circuit overhead line supported on steel towers. |
| 2. Kendoon to Glenlee. |
| This will involve building a new 132kV double circuit overhead line supported on steel towers. |
| 3. Carsfad to Kendoon. |
| This will involve building a new 132kV single circuit overhead line supported on wooden poles. |
| 4. Earlstoun to Glenlee. |
| This will involve building a new 132kV single circuit overhead line supported on wooden poles. |
| 5. Between Glenlee to Tongland. |
| This will involve building a new 132kV double circuit overhead line supported on steel towers. |
In addition, although we will not need to build any new substations, we will need to extend our existing 132kV substation at Glenlee to accommodate new equipment needed to operate the new lines. This work needs to be completed first and will be subject to a separate planning application to Dumfries & Galloway Council in 2018. We may also need to carry out a minor boundary extension to our existing Kendoon substation.
Once the new overhead lines are operating, we will be able to remove the existing overhead lines that we no longer need.
Our new overhead lines will be mostly double circuits. This means they can carry more power compared to the existing single circuit lines. This is the most efficient way to provide the extra resilience and security the local electricity supply needs. It will also provide some extra capacity, giving us more flexibility for future developments. However, we will need to use a different, larger type of steel tower to support the new overhead lines. Our existing towers (PL1), have a standard height of 20m, and our proposed new towers (L4 and L7), have standard heights of 26m and 27m tall respectively. Exact heights of individual towers will vary depending on local topography and landscape features, such as roads and watercourses, to ensure safety clearances are maintained. The new towers will also have six arms instead of three. That’s because each of the two new circuits has three sets of wires and there is also an earth wire which runs along the top. Further details on the tower design, including the range of tower heights, are included in our 3rd round consultation document.
At some points we can still use single circuit overhead lines but these will be supported on wooden poles rather than the steel towers which are there at the moment.