The deal is for 31 V112 3MW turbines to go to the Tsitsikamma wind farm in Eastern Cape province. The contract includes a 15-year service agreement.
Delivery is set for Q2 2015, with the aim of bringing the project online by Q1 2016.
Indian utility Tata Power and Exxaro, South Africa's second-biggest coal producer, formed a 50:50 joint venture at the beginning of the year to develop, own and operate electricity generation projects in South Africa, Botswana and Namibia.
The new company, Cennergi Ltd, will initially focus on renewable energy projects in South Africa. The longer-term strategy is to create a balanced portfolio of generation assets.
This is the second order South African order Vestas has won in the last month. In June, GDF Suez handed the company a 94MW contract to deliver V90 2MW turbines to the Aurora project in Western Cape.