Two Duke Energy wind power projects recently under construction in Pennsylvania and Wyoming are now online and generating clean, renewable electricity. Duke Energy also announced that Siemens Industry Inc. would join General Electric as a wind turbine supplier for a 200-megawatt wind farm Duke Energy is planning to build near Casper, Wyo.

Duke Energy’s 70-megawatt (MW) North Allegheny Windpower Project is producing electricity for FirstEnergy under a long-term power-purchase agreement (PPA). Duke Energy assumed ownership of the development project—located in Pennsylvania’s Blair and Cambria counties—from Gamesa Energy USA earlier this year. North Allegheny represents Duke Energy’s first commercial wind farm in the eastern United States.

Duke Energy also recently brought its 42-MW Silver Sage Windpower Project in Cheyenne, Wyo., online. Silver Sage is the company’s second wind farm in the area; the nearby 29-MW Happy Jack Windpower Project entered commercial operation in September 2008. Under two long-term PPAs, Duke Energy will sell all of the electricity generated at Silver Sage to Cheyenne Light Fuel & Power, a utility subsidiary of Black Hills Corp., and Colorado-based Platte River Power Authority.

In addition, Duke Energy has finalized its wind turbine supply plans for the 200-MW Top of the World Windpower Project, which is scheduled for construction in Converse County, Wyo., in 2010. In addition to the already-announced 66 General Electric 1.5-MW turbines to be installed at the site, Duke Energy has entered into a supply agreement with Siemens Industry Inc. for 44 turbines, each capable of generating 2.3 MW.

Construction work at the Top of the World site is expected to begin in early 2010 upon receipt of all necessary permits from the state. PacifiCorp signed a long-term PPA with Duke Energy in late August to buy all of the renewable power that will be generated by the Top of the World project.

With North Allegheny and Silver Sage now online, Duke Energy has 634 MW of wind power in commercial operation. That total will increase to 733 MW by the end of the year, when final commissioning at Duke Energy’s recently constructed 99-MW Campbell Hill Windpower Project—also in Converse County, Wyo.—is complete.