Update - 4.40pm: The number of customers without supply due to Storm Doris now stands at 1,500.
ESB Networks' crews continue to repair the damaged electricity lines and they say that most customers will have their power restored this evening.
However, they did say that, due to the severity of the damage, there will be "small pockets of customers" without power for a second night.
Crews will continue to work until late tonight and will resume work early tomorrow morning to restore power to those remaining customers.
So far today, approximately half of the 600 individual faults on the system this morning have been repaired, with crews removing fallen trees and erecting new electricity poles.
Earlier: The ESB say all available resources have been deployed around the country to repair 600 individual faults on the network.
Repairs crews have now been working for two days, to repair the havoc caused by Storm Doris.
ESB's Paul Hand says repair work still continues in a number of areas.
"Up around 600 individual faults had to be repaired across the network around the country in areas exposed in a sweep - going from north Connacht through south Ulster and north Leinster.
"So there's still quite a lot of work to be done and crews are working tirelessly to get customers restored as soon as possible."