ESB Networks say customers in the most rural areas may be without power until Thursday.
Storm Darwin caused widespread damage to the electricity network, with the South of the country worst affected.
Over 25,000 customers remain without power this morning.
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The main faults are in Tralee, Newcastlewest, Fermoy, Dunmanway, Killarney, Bandon and Waterford.
Bevin Cody of ESB Network has this update: