Tucson Electric Power Co. has won state approval to buy power from a planned wind and solar energy farm near Willcox that would be the first utility-scale project of its kind in Southern Arizona.

The Arizona Corporation Commission approved the 20-year power purchase agreement between TEP and Red Horse Wind 2 LLC, which was formed by Houston-based Torch Renewable Energy to build and manage the 220-acre project. Construction is expected to start later this year, pending environmental studies, and the farm is expected to go online in 2014.

Starting in December 2014, TEP will be able to buy most of the plant’s 51-megawatt capacity, plus 3 megawatts of solar energy, which will fulfill about 1 percent of the utility’s renewable energy requirement. The state has mandated that TEP and other regulated utilities get power equal to 15 percent of their retail sales from renewable sources by 2025.