Endeavour Energy's infrastructure has been hit hard by this summer's bushfires.

The provider's coverage area includes the Blue Mountains, Southern Highlands, Illawarra and South Coast.

So far, around 45 per cent of the Endeavour Energy coverage area has been affected by fire.

Ausgrid, the distributor in the North Coast area, has sent down crews to assist in restoring power.

As of Thursday a spokeswoman estimated all but 300 customers have the power back on at their homes and businesses.

Endeavour Energy will contact those residents without power to give an indication of their likely restoration time.

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Some of those premises with power are drawing it from generators as the power lines in their area are yet to be repaired.

"[On Wednesday] generators were installed in some South Coast towns that have been without power for more than a week," the Endeavour Energy spokeswoman said.

"Over the coming days, it is hoped to provide more generators in small communities and isolated areas where repairs may take some time."

At present on the South Coast there are 41 generators powering individual homes and 11 "embedded generators" giving power to multiple homes.

All bushfire-affected premises in the Southern Highlands are being powered by the network.

Areas like Kangaroo Valley, where large burned trees had fallen across the road and restricted access, have not been connected to power yet.

The spokeswoman said it could be weeks until the electricity supply returns to normal.

"The final recovery of the network is a challenging effort that needs to be undertaken safely and methodically in the days and weeks ahead," she said.

"There is also a massive job ahead to remove burned and dangerous trees in close proximity to the network."

The spokeswoman also warned people that, in areas where there are burnt power poles and conductors on the ground, they should always assume all power lines are live.

They should stay at least eight metres away and call 131 003 to report power lines down, burnt poles and broken cross arms.