Coal producer Seriti Resources on Monday said it planned to invest $730 million in building a 450 megawatt wind farm in Mpumalanga to kickstart a foray into renewable energy following its proposed acquisition of Windlab Africa.

Privately-owned Seriti, a major coal supplier to South Africa's state power utility Eskom, plans to buy a 51% stake in Windlab Africa's wind and solar energy assets for $55 million.

Windlab Africa is currently owned by Australia's Windlab Pty Ltd and has 3.5 gigawatts of renewable energy projects at different stages of development in South Africa and east Africa.

Peter Venn, the Windlab Africa managing director who will head Seriti Green, the coal miner's renewable energy unit, said the 450 MW wind farm would cost 12 billion rand ($732.25 million) to build.

"We will be focusing on trying to build out 450 megawatts in Mpumalanga in Q1/Q2 next year, immediately post closure of this transaction," Venn told reporters.

Mpumalanga province hosts most of South Africa's coal mines and thermal power plants that employ thousands and is central to plans to replace the fossil fuel with renewable energy projects that will sustain local communities and businesses.

Miners of coal, a major source of carbon emissions, have come under pressure to wind down production of the fossil fuel amid a global push towards clean sources of energy.

"We need to be moving towards a lower carbon future through investing capital from coal into green energy. It is not only the right thing to do, but it makes business and societal sense," Seriti Chief Executive Mike Teke said in a statement.

Seriti produces about 50 million tonnes of thermal coal, the bulk of which is used to fire South Africa's power stations.