TransAlta Renewables Inc. says that Microsoft Corp. will buy the output from the 90 megawatt (MW) Big Level wind facility under construction in Pennsylvania.

The 15-year power purchase agreement is the third such deal that Microsoft has signed in the PJM Interconnection. Construction at the site, which is about 200 miles northeast of Pittsburgh, is underway.

TransAlta Corp. owns 61% of TransAlta Renewables and is one of Canada's largest wind generators and Alberta's largest hydro operator. It has a total of 8,000 MW of owned generation capacity across North America.

Commercial operation at the Big Level wind facility is expected to begin in the second half of 2019. All regulatory approvals have been completed.