Duke Energy will use 73 wind turbines, developed by Siemens, at its 168MW Ironwood Windpower Project in Kansas US.
The turbines are capable of generating 2.3MW of electricity. Siemens will also provide the nacelles that will be installed at the top of the wind turbine towers.
Duke Energy Renewables, a unit of Duke Energy, will build, own and operate the Ironwood Windpower Project, which can supply electricity to power more than 50,000 homes.
Under a 20-year agreement, Westar Energy will purchase the power generated at the plant.
Construction of the wind farm is slated to begin this year with commercial operation expected by mid-2012.