CHARLOTTE, N.C. — Duke Energy announced that it will build and operate a 200-megawatt (MW) wind energy project near Casper, Wyo. The Top of the World Windpower Project will be the company’s ninth U.S. wind farm and its fourth in Wyoming.

Duke Energy will construct the Top of the World project on approximately 17,000 acres of private and public land it holds under long-term lease in Converse County. The project — expected to reach commercial operation by the end of 2010 — will generate enough electricity to power the equivalent of 50,000 to 60,000 homes on an annual basis.

PacifiCorp, which operates as Rocky Mountain Power in Wyoming, will purchase all of the electricity generated by the Top of the World project and the associated renewable energy credits (RECs) as part of a 20-year power purchase agreement. PacifiCorp previously contracted to buy all of the output and RECs from Duke Energy’s nearby 99- MW Campbell Hill Windpower Project, scheduled to come on line later this year.

“We’ve always believed Duke Energy could become a major player in the wind power industry if we adhered to our strategy for organic as well as opportunistic growth,” said Wouter van Kempen, president of Duke Energy Generation Services (DEGS), a business unit of Duke Energy that owns and develops renewable energy assets. “Including Top of the World — which will be our second-largest renewable energy facility — we’ll have committed to four new wind projects totaling more than 360 megawatts this year alone.”

Duke Energy expects to start construction of the Top of the World project in late 2009 or early 2010, upon receipt of all necessary permits. Consistent with Gov. David Freudenthal’s executive order concerning the conservation of greater sage grouse, Top of the World will be constructed outside of sensitive core areas.

Duke Energy will use at least 66 G.E. turbines — each capable of producing 1.5 MW — at the Top of the World site. These units represent the balance of turbines Duke Energy arranged to purchase from G.E. in a procurement order announced in September 2008. Negotiations for the remainder of the wind turbine supply to be used at Top of the World are under way.

Duke Energy is one of the largest owners of wind power assets under construction in Wyoming. The company already owns and operates the 29-MW Happy Jack Windpower Project in Cheyenne, Wyo., and will soon complete the nearby 42-MW Silver Sage Windpower Project. With these projects and the additions of Campbell Hill and Top of the World, Duke Energy will own and operate approximately 370 MW of wind energy in Wyoming by the end of 2010.

In total, Duke Energy has more than 500 MW of wind-powered generation projects in operation — a figure that will rise to more than 700 MW by the end of 2009. The company also has an additional 5,000 MW in potential development projects.