Duke Energy has expanded its wind energy business with a long-term agreement for the sale of 99 MW of electricity from its Wyoming wind farm (USA).

The company also finalised plans for 100 wind turbines to produce 150 MW of power at various US wind projects.

Terms of the two contracts were not disclosed.

Duke Energy will begin building the Campbell Hill wind power project near Casper, Wyoming, early in 2009. The 66-turbine facility will begin generating electricity later in the year.

PacifiCorp, which operates as Rocky Mountain Power in Wyoming, has entered into a 20-year agreement to purchase all of the power generated by the Campbell Hill project. The output from the project will go into the utility's integrated electric system, serving customers in Wyoming, Utah, Idaho, Oregon, Washington and California.

Separately, Duke Energy executed an agreement to purchase the GE wind turbines for its 2010 wind power generation projects.

"Soaring interest in wind energy has translated into growing demand for turbines and a tightening supply," said David Marks, DEGS senior vice president for wind energy. "Securing wind turbines in a very competitive environment provide Duke Energy with the resources it needs to fulfill our commitment to clean, renewable energy."

Duke Energy Generation Services (DEGS) is a business unit of Duke Energy that owns and develops renewable energy assets.

By the end of 2008, Duke Energy will have more than 50MW of wind-powered generation projects in operation and an additional 5,000MW in development.