Constellation Energy Group, the parent of Baltimore Gas and Electric Co., said Wednesday it closed a deal to buy a $140 million wind energy project in Garrett County that is expected to start operating by the end of the year. Constellation is buying 28 2.5-megawatt wind turbines from Clipper Windpower Inc. The 70-megawatt project will generate 125 new jobs during construction. The project is part of Constellation's push to promote and expand its clean-energy offerings in the Mid-Atlantic area. Constellation struck a 20-year power purchase agreement with Old Dominion Electric Cooperative for renewable energy credits produced at the wind turbine facility.