Thousands of properties without power as widespread blackout hits Wollongong

Endeavour Energy sent a text message to affected customers just after 7pm on May 24, notifying them that work was underway to fix the problem.

The energy company said the cause was under investigation and they expected the electricity to be restored by 1.30am.

The fresh outage comes after more than 1700 properties in the Wollongong CBD were hit by a power outage about 11.45am, just as many businesses were getting ready for the lunchtime rush.

The outage stretched from areas near Stuart Park in the north, then south towards Burelli Street, and west through Kembla Street towards Gipps Street.

A power line came down near the intersection of Corrimal and Campbell streets, forcing the closure of the road. The road has since reopened.

Earlier, an Endeavour Energy spokeswoman said technicians did not know why power went out across such a large section of Wollongong.

"There's a fault at our North Wollongong substation," she said.

"Crews are investigating and we don't have an estimated time for power to be restored."

Earlier this month power was cut to 60,000 properties across the northern Illawarra, with multiple outages overnight between May 5 and 6.

Endeavour Energy said wet and windy weather was to blame.