JOHANNESBURG - Calling all South Africans: be sparing with electrical appliances after 4 p.m., think twice about whether you really need to boil so much water for that tea, and don't even think about switching on your air conditioner after dark.

These were among the pleas state power company Eskom's outgoing chief executive made to long-suffering consumers in Africa's most industrialised nation on Sunday, as he reassured them recent maintenance work would ease some of the harshest blackouts in living memory.

But outgoing CEO Andre De Ruyter also re-affirmed that power cuts would continue for two more years at least.

Earlier this month households were without electricity for at least six hours a day, sometimes as much as 10 hours, with freezers thawing and businesses forced to crank up diesel generators.

South Africans were braced for worse, with the risk of "stage 8 load shedding" - more than half a day with no power.

"That possibility is receding, which is comforting and positive," De Ruyter told a virtual news conference on Sunday. The current schedule was for lower "stages" of outages that are roughly equal to less than four hours a day.

But he added that there was always an "inherent risk" it could get worse if further outages happen during peak demand.

"We would really urge South Africans to plan (evening) consumption such that ... we have reduced demand," he said. "Switch off air conditioners, only boil water that you need - don't fill the kettle up. These small steps will really make a difference."

Creaking coal-fire power stations, corruption in coal supply contracts, criminal sabotage and failure to ease up regulation to enable private providers to swiftly bring renewable energy on tap have all left South Africa in a deep power deficit.

Voters could well punish the ruling African National Congress (ANC) in national elections next year.

Eskom's Chief Operating Officer Jan Oberholzer said that by the end of March the firm should be able to bring 1,862 megawatts back online, and that it would focus on keeping its top six power stations running smoothly.

"We remain acutely aware of how our poor current performance is impacting the country," he said. "We are working tirelessly to address this."

(Reporting by Tim Cocks Editing by Tomasz Janowski)