The company was named as a preferred bidder under the government's Renewable Energy Procurement Programme (REIPPP).
Construction is set to begin in early 2016, with the project due online in "late 2017". Gestamp said total investment in the project would reach €150 million
Gestamp Wind CEO Dionisio Fernandez said the company has a further 785MW of projects under development in South Africa.
The additional capacity would be submitted in to future government tenders, he added.
The Copperton project will be Gestamp's second in South Africa. Its 73.8MW Noblesfontein project was completed in July 2014. The project uses Vestas V100-1.8MW turbines.