Overall, 36,000 customers across the Mid North Coast and the Upper Hunter lost power as the storm caused extensive damage across the electricity network.

On Monday afternoon, 7200 customers were without power, but it was expected 2500 would be without power overnight.

The majority of customers affected were in the Dungog and Bulahdelah areas, which were hit particularly hard.

Centres where power has not been fully restored by Monday afternoon included Clarencetown and North Arm Cove, as well as some customers outside Taree and Wingham.

Essential Energy sourced 40 extra crews from across the region and the north-west who joined local teams to concentrate on the hardest hit areas in the south of the region.

Regional manager, Brendon Neyland, said power was progressively restored, but with multiple faults on some of the high voltage lines in rural areas, it was a slow process.

As well as repairing the high voltage damage, there were a large number of low voltage faults at individual premises that would be repaired over coming days.

"Our aim at this stage is to get the largest number of people on in the shortest time," Brendan said.

"Damage to the network has been extensive and as always, our number one priority is safety - both for our workers and the public."

To report a supply interruption, fallen powerline or network damage, telephone 13 20 80. Always stay at least eight metres away from damaged infrastructure. Never touch a fallen powerline or any object it is in contact with, as it may still be energised.