AUTHORITIES in South Australia are making good progress in repairing damage left by Friday's extreme storms.

More than 120,000 lightning strikes were recorded across the state on Friday, with up to 14,000 in only one hour during the evening.

The industrial town of Whyalla took a battering from the electrical storms, leaving at one stage more than 5000 people without power.

Authorities say power to most homes was reconnected by yesterday, but up to 300 were without power for a second night and some may face another night in the dark.

In the wine regions of the Barossa and Clare valleys, some 500 homes still had no power last night, although thousands of other customers have been reconnected.

Hundreds of people in Port Pirie, north of Adelaide, have also had no power, with an official saying there's a lot of damage, and repairs in some cases will take time because of the equipment needed.