The $2.5 billion project Plains & Eastern Clean Line project will transport 4GW of wind energy from the Oklahoma Panhandle region east to Arkansas, Tennessee and other parts of southeastern US.
Construction of the 1,135km privately funded line could start in 2017, said Clean Line.
The DoE approval marks the first use of Congressional authority shifted to DoE under the Energy Policy Act of 2005 to promote grid development.
"Building modern transmission that delivers renewable energy to more homes and businesses will create jobs, cut carbon emissions, and enhance the reliability of our grid," said US energy secretary Ernest Moniz.
The line could help drive more than $7 billion dollars in new wind farm development, said the American Wind Energy Association.
However, Republican Senator Lamar Alexander of Tennessee, was less enthused: "This is the first time federal law has been used to override a state's objections to using eminent domain for siting electric transmission lines. It is absolutely the wrong policy."