All flights at Dublin Airport have been suspended until Saturday morning.
Management say it is unlikely that there will be any flights on Friday.
Flights are expected to resume on Saturday morning.
Hundreds of flights had already been cancelled or delayed, with Ryanair pulling all its flights since Wednesday and Aer Lingus only attempting trans-Atlantic routes.
The ESB has asked customers to check if their fault has already been reported on powercheck.ie before they call.
As well as staying indoors, people are being reminded to check on the elderly and take pets in from the cold.