10pm: Power has been restored to homes in Thirroul, Bulli and Woonona, according to the Endeavour Energy website.
Earlier: Thousands of northern Illawarra homes have been plunged into darkness after a fast-moving storm swept over the region on Tuesday night.
Emergency crews from Endeavour Energy are working to get power back to about 11,000 homes and businesses in the Illawarra and parts of Western Sydney on Tuesday night.
Strong winds brought trees and branches over power lines and lightning strikes hit two major substations, the company said.
Power has been lost to the Bulli Zone Substation after lightning damaged both major cables to the site.
The company was working to restore power to 2775 homes in Thirroul, another 2655 in Bulli and 845 in Woonona.
Other areas without power include parts of suburbs Appin, Helensburgh, Stanwell Park, Douglas Park, Wilton and Otford, as well as Bowral, Berry, Culburra, Kangaroo Valley, Berry and Broughton Vale in the Southern Highlands.
Endeavour Energy said it was bringing in extra crews to assist with restoration efforts, but has asked customers to be patient due to the extensive damage to the network.
At 8.40pm the company’s website listed an estimated restoration time as 6.30am for homes in Thirroul, Bulli and Woonona.
Customers who rely on power supply for medical equipment are advised to check their battery supply and consider acting on their back up plan.
People are warned to keep well clear of fallen power lines as they may be live and to report them by calling 131 003 and to report electrical emergencies. Wait to speak to an operator if needed.
Customers can check power updates for their area by calling 131 003 and entering their postcode or entering their suburb into the power outage application at www.endeavourenergy.com.au
Read more: Tuesday night’s flash storm as it happened