The province's Independent Electricity System Operator (IESO) will issue a request for qualifications for the new supply, plus another 330MW of solar, small hydro and bioenergy, by 1 August. It expects to select winners by May 2018.
The new purchase plans come just weeks after the Canadian province awarded contracts in its first competitive procurement since ending its feed-in tariff (FIT) programme.
The IESO announced it would buy wind energy from five projects at an average cost of C$0.0859/kWh (US$0.06541/kWh)
The Ontario government expects to save C$3.3 billion by replacing the FIT with a competitive process, energy minister Bob Chiarelli said in a speech to CANWEA's annual spring forum, currently taking place in Quebec.
"The price for wind power is now on a level playing field with other forms of generation in Ontario, and is for the first time below the average cost of electricity production in our province," he said.