Our Networks
Transmission System
The nationwide electricity transmission system carries large volumes of electricity at high voltages (400kV, 220kV and 110kV) from generation stations to bulk supply points near the main towns and cities. From these, it connects with the distribution system, as well as to transmission systems in Northern Ireland and Britain. See Table 1 for data on ESB’s transmission system.
Table 1 - Data on the extent of the Transmission System owned by ESB
Transmission Lines (km) Transmission Stations(km)
Description | Quantity |
| 400kV Overhead Lines | 438 |
| 400kV Stations | 5 |
| 400 kV Underground Cables | 1 |
| 220kV Stations | 26 |
| 220kV + 275 kV Overhead Lines | 1821 |
| 110kV Stations | 45 |
| 220kV + 275kV Underground Cables | 163 |
| 400/20kV Transformers | 8 |
| 110kV Overhead Lines | 4245 |
| 275/220kV Transformers | 3 |
| 110kV Underground Cables | 292 |
| 110kV Submarine Cables | 16 |
| 220/110kV Transformers | 57 |
ESB Networks builds and maintains the transmission system. Eirgrid manages the power flows, including electricity generated by each major facility. Eirgrid also ensures that the transmission system can meet the growing demand for electricity in the future and allow more electricity to come from renewable sources, such as wind farms.
Distribution System
The distribution system delivers electricity from the transmission system to 2.3 million customers in Ireland, operating at 110kV in the Dublin area, and at 38kV, 20kV, 10kV and low voltage (LV) nationwide. In serving Ireland’s large rural population, the network length per capita is four times the European average and overhead lines outnumber underground cables 6 : 1.
Table 2 - Distribution System Statistics
| Quantity | Description |
|---|---|
| 2.1 million | Wooden Poles |
| 150,000 km | Overhead Line |
| 22,000 km | Underground Cable |
| 242,000 | Pole Mounted MV/LV Transformers |
| 21,680 | Ground MV/LV Substations |
| 133 | 110kV/38V or 110MV substations |
| 438 | 38kV/MV Substations |
| 2.5 million | Meters |
