The move will help Exxaro consolidate its interest in renewable energy at a time when South Africa needs energy security amid increasing negative sentiment towards coal-based electricity generation, said Exxaro Chief Executive Officer Mxolisi Mgojo.
South Africa, Africa's most advanced economy and also its worst polluter, generates most of its energy from coal-fired power plants that emit millions of tonnes of carbon dioxide into the atmosphere.
Exxaro bought the stake from Khopoli Investments, a subsidiary of Tata Power Company, and said the agreement was subject to regulatory approvals.
Cennergi, the joint venture, owns two wind farms in the Eastern Cape province with a projected 2019 earnings before interest, tax, depreciation and amortization (EBITDA) of around 850 million rand.
($1 = 14.6837 rand)
(Reporting by Tanisha Heiberg; Editing by Subhranshu Sahu)