The U.S. Department of Energy says it has approved a loan to Nissan North America Inc., which the auto maker will put toward renovating its Smyrna, TN, plant that will produce the Leaf electric vehicle and its lithium-ion batteries.

The DOE will front the auto maker $1.4 billion, less than the $1.6 billion Nissan initially indicated it was set to receive.

“During the loan process, we found some efficiencies that resulted in the slightly lower loan,” NNA spokesman Fred Standish tells Ward’s. Those efficiencies are confidential, he says.

The money will come from the Advanced Technology Vehicles Manufacturing Loan Program, which has available $25 billion to fund clean-energy projects that benefit the U.S. and reduce America’s dependence on foreign energy.

“Nissan is committed to zero-emission mobility,” says Scott Becker, NNA vice president-administration and finance, in a statement. “This loan, which will bring production of the Nissan Leaf to Tennessee, is a significant step in sustaining American jobs and American manufacturing.”

Nissan expects the loan to result in up to 1,300 jobs when manufacturing of both the Leaf and its batteries is at full capacity. Plant construction is set to begin later this year.

The Leaf will be imported from Japan starting in December until Smyrna production comes on line in 2012.

Nissan has said it will assemble the Leaf on existing car lines at Smryna, which will have the capacity to build 150,000 Leafs and 200,000 Li-ion batteries.

Last year, Nissan assembled 192,850 vehicles at Smyrna, Ward’s data shows.