The company has also developed a similar wind farm directly east across the Missouri River, in northern Burleigh County.
FPL said it plans to sell the power from its Oliver County wind farm to Minnesota Power of Duluth, Minn.
Construction should employ up to 150 workers, the company said. The wind farm is scheduled for completion by year's end.
A number of dignitaries attended Wednesday's groundbreaking for the project, including Gov. John Hoeven, Sen. Kent Conrad and Rep. Earl Pomeroy.