The ESB says 30,000 additional customers have lost electricity since this morning.
In its latest update, it says 34,000 homes, farms and businesses are without power.
It says ongoing snowfall is causing new faults - mainly in Enniscorthy, Arklow, Portlaoise and Cork.
In a statement, ESB says: "Due to these new faults, access issues, and worsening weather in the South East, it will be tomorrow at the earliest before some customers will get electricity back.
"Cork, Enniscorthy, Arklow, greater Dublin area and eastern counties of Leinster the main areas affected".
It says since Friday morning, "good progress" have been made on the faults in the greater Dublin area.
However, worsening weather in the south east has caused power to be lost to an extra 30,000 customers.
"We will continue to work with the emergency services and local authorities to ensure the safety of the pubic and to minimise disruption and are working with other state agencies to help us gain access."
For all faults log on to powercheck.ie
Image: ESB Networks
The ESB has asked customers to check if their fault has already been reported on powercheck before they call.
Dramatic moment the power goes out over Dublin City -caught in this video @KennedySinger @katherinelyncho @thetenoruk #SNOWMAGGEDDON pic.twitter.com/xNsxnO1Epf
— Niall Morris (@NiallwMorris) March 2, 2018
