JOHANNESBURG - Eskom is looking at at least R30 million in repair work at its Zola substation following Tuesday's fire.
Vandalism of transformers has been given as the cause for the fire.
Questions have been raised about the security employed at the power utility.
Restoration began late Tuesday with power being routed from different substations in Soweto.
Healthcare facilities, daycare centres and schools were among those affected.
The Happy Day Care Centre in Jabulani is in one of the areas not restored on Tuesday night.
While the facility was still able to prepare meals, the impact of the outage was visible.
Most affected government medical facilities were able to continue operating through backup power supply. Generators are part of the contingency plan to address short-term outages.
Meanwhile, Eskom says it may need to do more to protect the Zola substation from similar incidents.