Eskom implemented rolling blackouts over the weekend in order to build up diesel reserves.
KIEV - Ukraine on Wednesday announced a state of emergency for its energy sector that could result in rolling blackouts as officials try to sharply curtail electricity use by consumers.
The decision was made at a cabinet meeting to work out a response to a two-week strike by ultra nationalists who have blocked a railroad between the coal-producing eastern regions and the rest of Ukraine.
Kiev has continued to buy a specific type of coal produced only in the Russian-backed separatist east that is needed to fuel the country's power plants.
The exchange of goods has gone on even as a 34-month conflict has claimed more than 10,000 lives and unsettled eastern European states that were under the Kremlin's thumb in the Cold War era and are wary of an increasingly assertive Russia.
Energy Minister Igor Nasalyk said the most immediate measure involved a call to all people to try to save power in their industries and homes.
But he also warned that energy conservation efforts may not be enough.
Nasalyk said that "we will implement rolling blackouts to balance out the work of Ukraine's energy system" if the power savings are not sufficient.
The far-right protesters defend their actions by saying Kiev should not be trading with militias who are trying to carve out their own fiefdom near Ukraine's border with Russia.
Ukraine's pro-Western leaders have refused to break up the railroad blockades for fear of sparking a backlash among a large proportion of the population that is sympathetic to the protesters' cause.
Nasalyk said the coming weeks would see Ukraine rely more heavily on plants that use natural gas to produce electricity and limit the use of coal.
Prime Minister Volodymyr Groysman told the meeting that the railroad protest was a "crime".
"These blockages could leave hospitals and Ukrainian homes without power," Groysman said.
"But fighting ordinary people is inadmissable," he added.
The prime minister said he was also willing to fight "contraband" allegedly being transported along the railroad by the rebels.
The protesters believe that the insurgents use train cars to carry guns and soldiers to specific flashpoints and have entered enemy territory to stop the trains' movements.