The company announced the plan Tuesday but gave few details.
David Eves, president of Xcel's Colorado operation, said the wind farm would occupy land in several counties but declined to say which ones. He also declined to say how much it would cost.
He said more details would come in May.
Xcel currently has the capacity to generate 2,500 MW with wind, enough to power about 1.3 million homes for a year.
The industry group American Wind Energy Association says Xcel has more wind power than any other U.S. utility, including both power it generates and purchases.
Xcel is based in Minneapolis.