The environmental committee of Chile's Atacama region approved the Sarco project in the centre of the country.
The 94 turbines will each have a capacity of 2.5MW, but a supplier is yet to be named.
Construction is expected to start in the first quarter of 2015, with the project due to be commissioned in early 2016.
The power will be transported to the grid through a 56-kilometre export cable at the Maitencillo-Punta Colorada substation.
Around $500 million will be invested in the project.
Mainstream has made a big push into the Chilean market, with around 2.3GW of wind projects under development in the country.