Electricity supplier Eskom urged consumers to use power sparingly while it continued with the maintenance of generating units.
It recommended that homeowners and businesses switch of geysers, pool pumps, non-essential lights, and efficiently use airconditioners between 5pm and 9pm.
"We call on all South Africans to pull together over the next few months and use electricity sparingly by living lightly this summer," Eskom said in a statement.
It said it had met the demand for electricity at the weekend.
On Sunday, the peak demand was 28,407MW with 32,845MW available.
Eskom said it had enough power for the coming week.
"We have seen a few generating units that were out for maintenance coming back on line, thus relieving some pressure from the power system.
"However, our request for our customers to keep demand as low as possible remains, in order to ensure that we continue with planned maintenance and have enough spare capacity in case of unplanned events."
On Monday, the demand for electricity was expected to be around 30,966MW, with 34,200MW available.
Eskom said planned maintenance stood at 5000MW, but that unplanned outages of around 4000MW were expected.
"Peak demand for the rest of this week is forecast at 30,869MW on Tuesday, 30,783MW on Wednesday, 30,718MW on Thursday, 30,248MW on Friday, 28,955MW on Saturday and 28,538MW on Sunday," it said.