We are responsible for constructing all the sub-transmission, medium and low voltage electricity network infrastructure in the country and for managing this infrastructure which is owned by ESB.

The electricity distribution network includes all distribution stations, overhead electricity lines, poles and underground cables that are used to bring power to Ireland's 2 million domestic, commercial and industrial customers.

For electricity supplied at Low Voltage by ESB Networks, the nominal standard is 230/400 Volts, 50Hz.. ESB Networks undertakes to deliver single phase electricity within a voltage range of 207 Volts to 253 Volts. This is in accordance with European Standard EN50160.

ESB Networks manages the transmission assets which are owned by ESB and ensures that the transmission infrastructure is developed and maintained in accordance with the requirements set down by Eirgrid.

The ESB Networks business builds, operates and maintains a nationwide distribution system which includes 235,000 transformers and almost 160,000 km of distribution networks (i.e. overhead lines and underground cables). These activities are undertaken by our staff who are located in our thirty four geographical areas throughout the country. As owners of the nationwide transmission system, we are also responsible for carrying out the construction and maintenance of the high voltage 400kV, 220kV and 110kV transmission system, comprising over 6,600 km of overhead lines and 30 large transmission stations.

Over the current four year period 2007 - 2010, a major investment programme of €2.5 billion is being undertaken by ESB Networks to upgrade electricity infrastructure around the country, in addition to a total of €4.0 billion already invested by ESB Networks between 2001 and 2006. When completed, this will further improve and strengthen the electricity networks countrywide and will considerably enhance the security of supply to existing customers. It will also ensure that a world class infrastructure is in place to support continuing economic development into the future.

The following link will direct you to a map illustrating the geographic structure of ESB Networks' operations throughout the country: Map of ESB Networks' Ltd. Divisions and Areas

Transmission Asset Owner

The Transmission Asset Owner (TAO) function is an integral part of ESB Networks' organisation. The role of the TAO is to ensure that the Transmission System is developed and maintained in accordance with the requirements set down by EirGrid, which is the Transmission System Operator (TSO). ESB Networks has a country-wide presence of highly skilled technicians and is ideally organised to be able to deliver this function.

The TAO has responsibility for the management of the Transmission capital and maintenance work programmes. This includes the building of new High Voltage substations and their associated overhead lines and underground cables; it also involves responding to network faults and carrying out planned maintenance and refurbishment works on these assets.

ESB Networks works very closely with EirGrid, the Transmission System Operator (TSO).
The TSO is responsible for operating the network of High Voltage Transmission lines and substations to transport power from the various electricity generators to locations where it is needed around the country, and is playing a key role in the operation of the All-Island Market for electricity. Access to the Transmission System is under the control of EirGrid.

There is a legal agreement in place between EirGrid and ESB Networks ("Infrastructure Agreement") which sets down the terms under which ESB Networks provides infrastructure services to EirGrid.

Visit the EirGrid website