At the height of the natural disaster, around midday on Wednesday, the energy provider confirmed 225.000 customers were without electricity across the Hunter, Central Coast and Sydney regions.

More than 95,000 customers have had their power supply restored and 130,000 homes and businesses are on the waiting list.

Of these 130,000 about 75,000 are in Newcastle and the Hunter where gale force winds and heavy rains were the most destructive.

Ausgrid said 1400 staff, supported by emergency crews from Essential Energy, Endeavour Energy and Queensland's Energex, will continue their work this weekend and into next week in some locations.

More crews will join the effort on Friday to help repair major power lines and sub-stations, remove trees from power lines, re-stand poles and re-string wires across the network.

SES volunteers ferried Ausgrid crews through floodwaters to get power back to parts of Gillieston Heights on Thursday night.

The energy provider said flooding around Maitland and neighbouring centres is expected to slow the progress of repair work in those areas.