CHARLOTTE, N.C. (AP) — Duke Energy has announced plans to expand its use of wind-produced electricity and to purchase more wind turbine generators.

The North Carolina-based utility said Tuesday it has a 20-year contract to sell all the electricity from its planned 66-turbine wind farm near Casper, Wyo., to PacifiCorp. PacifiCorp serves customers in Wyoming, Utah, Idaho, Oregon, Washington and California.

A Duke spokesman said 1 megawatt powers about 800 homes with traditionally generated power.

Duke also said it was buying 100 General Electric wind turbines that will produce 150 megawatts at U.S. sites. By the end of 2008, the utility plans to have more than 500 megawatts of wind-powered generation projects in operation and another 5,000 megawatts in development.

Duke currently produces less than 1 percent of its electricity from renewable sources.