Constellation Energy Source, a unit of Constellation Energy Group, has won a USD 43.6 million contract to design, build and operate an energy plant in downtown Nashville, Tennessee, USA. The initial contract spans 15 years but Constellation’s deal with the governments of Nashville and Davidson County includes three five-year extensions that could reap the Baltimore-based company an extra USD 105 million. The plant will be designed to heat and cool 39 major buildings.