Essential Energy says tens of thousands of customers lost power in the weekend storms.
Regional General Manager, Matt Patterson, says the weather event is one of the worst he's ever seen while working with the energy provider.
"At the height of the storms 25,000 customers were out from Walgett to Tamworth and everywhere in between," he said.
"About 40 to 60 poles were brought down during the storms and we now have to make aerial assessments of the damage."
Essential Energy says major progress was made to restore power to households and businesses in the 24 hours after the weather event.
Just over 5,000 customers were without power a day later, mainly in Narrabri, Coonabarabran, Gunnedah and Moree.
That number was reduced to 1,700 within two days.
Essential Energy says fires have also caused considerable damage to the network, especially around Barradine.
It says up to 200 poles may have to be replaced across the New England North West and into the Central West as a result of the storm and fire damage.
© ABC 2013
13:37 EST A hail storm barged through Sydney yesterday afternoon, bringing 1-2 cenimetre-sized pellets and heavy downpours, effectively turning summer into winter.