A 2013 study by the American Council for an Energy-Efficient Economy reported that battery costs came down from per kilowatt hour in 2007 to per kilowatt hour in 2012. The U.S. Department of Energy has set cost targets for its sponsored battery research of per kilowatt hour in 2015 and per kilowatt hour by 2022. Cost reductions through advances in battery technology and higher production volumes will allow plug-in electric vehicles to be more competitive with conventional internal combustion engine vehicles.