More South Africans than ever must have enjoyed candlelight dinners during Earth Hour as Eskom reported on Sunday drastically reduced energy usage during this time frame.
"South Africans remembered their combined power, switched off and achieved a massive 629MW average reduction on their electricity usage," said Eskom in a statement.
The power utility said the savings took place during Earth Hour between 8.30 and 9.30 on Saturday night.
Last year, South Africans reduced their energy usage by approximately 402MW during earth hour - enough electricity to power Bloemfontein.
"This year's figure shows that more and more South Africans are seeing the value of switching off what they are not using."
On Saturday, Public Enterprise Minister Malusi Gigaba warned South Africans to brace themselves for what could be the most difficult winter "as electricity supply remained constrained".
"We need to worry about how we are going to go through this winter," Gigaba told residents in Kliptown, Soweto.
Earth Hour started in 2007 in Sydney, Australia, when private households and businesses turned off their lights for an hour to take a stand against climate change.