Solar water heaters benefit S.Africans by providing free and endless supply of water. "The geysers use the sun to heat up the water. My electricity is not affected and I have even stopped using my paraffin stove as it was dangerous," said the mother of two from Zwide township in the industrial city of Port Elizabeth.
Eskom offers a basic free allowance of electricity to low-income South Africans, which is enough to keep the lights on but not enough to have regular water for bathing or cleaning.
So many use paraffin stoves that are a leading cause of home fires which can be hard to contain in crowded neighbourhoods.
Mali is one of the 30,000 beneficiaries in Port Elizabeth, where the black and silver rooftop geysers have become known locally as "flies", because of the way they look from a distance, shimmering in the sun.
Eskom's objective is to install one million solar water heaters throughout country by 2015, with tens of thousands already installed in other cities around the country.
The company is offering 110-litre geysers for free in township homes, but wealthier families needing larger volumes also receive a subsidy to encourage them to switch to solar.
Eskom has so far spent 340 million rands ($49 million, 35 million euros) on its rebate programme.
"Eskom and government's joint objective is to save energy and to encourage the use of renewable energy, as well as to provide relief to low income households," said Eskom spokeswoman Hillary Joffe.
The solar project has already reduced the demand for electricity by 22 megawatts, she said.
That's a tiny fraction of the power produced by a coal power plant, but about one-fifth of the electricity that would be generated by a planned solar field in the arid Northern Cape.
South Africa has dramatically expanded access to electricity since the end of white-minority rule in 1994, but nearly one in five people still has no power at home.
Expanded access has left Eskom battling an electricity shortage due to a lack of investment in new capacity and an ageing power stations that resulted national blackouts in January 2008.
Massive new coal plants are being built to cope with South Africa's energy needs, but international loans for those projects have also required the country to commit more resources to renewables.
The country already emits half of Africa's greenhouse gas emissions, mostly from coal-powered power stations.
The African Development Bank earlier this month approved a $365 million loan to help fund Eskom's wind and solar projects.
The country also keen to be perceived as more environmentally friendly in the run-up to UN climate talks in November in Durban, which will seek to create a deal to follow up on the Kyoto Protocol.