FERGUS FALLS, Minn. (AP) ¿ Energy provider Otter Tail Corp. on Friday said its unit Otter Tail Power Co. will build a 49.5-megawatt wind farm in North Dakota, near Lake Ashtabula. Construction will begin this month and the company expects the project to be operational by the end of the year. The wind farm will be north of the existing 200-megawatt Ashtabula Wind Energy Center, which was constructed in 2008. Otter Tail said it expects this facility to be part of a larger project, the Luverne Wind Farm, comprising 169.5 megawatts built by NextEra Energy Resources LLC, an affiliate of FPL Group. NextEra Energy Resources will serve as construction manager and initial operator of the wind farm located in Steele and Griggs counties. Otter Tail Power Company will construct a 13-mile 230-kilovolt generation outlet needed to transmit the electricity. Otter Tail plans to invest about $110 million in this project and will apply for a 30 percent treasury grant available through the American Recovery and Reinvestment Act of 2009, the company said. Shares of the company fell 6 cents to $18.85 Friday afternoon.