Around 70 NIE crew members are heading to the Republic with a convoy of vehicles and equipment to rebuild electricity networks shut down by this week's storms.
The overhead line crews and tree cutters will be helping repair overhead lines brought down by trees and storms in the Portlaoise area.
They will help to restore power to tens of thousands of homes that have been left without power in the wake of the record-breaking winds.
Overhead line and tree cutting teams from all over Northern Ireland left yesterday to work alongside colleagues in ESB networks, travelling with specialised equipment, such as mobile elevation platforms, tree cutting equipment and four wheel drive vehicles.
Kevin McDowell, head of health, safety and environment, said: "In this business we need to respond quickly so it's good to help out colleagues when we can – it only takes the wind to change for us to have to call in those favours."