It could be another day before power is restored to all affected properties across South Australia after severe weather.
The weather bureau says there have been more than 170,000 lightning strikes in the past day or so.
Wind gusts of up to 96 kilometres per hour brought down trees and powerlines, cutting electricity to more than 80,000 properties.
Paul Roberts from SA Power Networks says work continues to restore supplies to about 4,000 of the affected customers, after storms affected Adelaide, Eyre and Yorke Peninsula, the mid-north and Kangaroo Island.
"It's been really violent storms. It's left damage across the network from the far west coast, Ceduna, right through the city and into the hills and beyond," he said.
"It's going to take us considerable amount of time to get people back on. I imagine there is definitely going to be people without power through to Melbourne Cup time and I would almost guarantee that will have some customers without power overnight again tonight (Tuesday).
"It's just simply such a large-scale job. We're swinging in extra crews and asset inspectors, we've got helicopters up in the air to assist us."
The State Emergency Service has responded to more than 120 calls for help in the past day.
An ambulance crew took a 15-year-old boy to Flinders Medical Centre after he was hit by lightning at Hallett Cove in Adelaide's southern suburbs.
He was conscious when the emergency crew arrived and in a stable condition after being admitted to the hospital.
The lightning strikes which have lashed the state since Sunday also have sparked grass and scrub fires.
The Country Fire Service says it has battled more than 50 blazes and several fires are still burning.
Julie Smith, from the Hawker Hotel-Motel, said the power had been out since late on Monday and she hoped it would be back before too much food was lost.
"We've just got to cope with it don't we?" she said.
"We've still got cans and things like that we can put on ice - you make do."
© ABC 2012
17:27 EST Wallsend businesses have welcomed the introduction of a Flash Flood Early Warning system, but say it will not protect their properties from water inundation.