Volkswagen's efforts in Chattanooga to produce Passats using the sun has put it on a federal list of top green power purchasers.
The U.S. Environmental Protection Agency has ranked the VW factory, which recently opened the biggest solar park in Tennessee, as the 11th best on its top 20 list of on-site buyers of green energy.
Blaine Collison, who directs EPA's Green Power Partnership, said in a statement the plant is helping cut harmful air pollution and "demonstrating that using green power is smart for the environment and for business."
Frank Fischer, who heads VW's operations in Chattanooga, said using green power helps it improve its environmental efficiency and confirms its status as the only Leadership in Energy and Environmental Design Platinum-certified auto plant in the world.
VW's 33-acre solar park adjacent to the plant that assembles midsize Passat sedan supplies about 12 percent of all its energy needs.
Silicon Ranch, a Nashville company started by former Gov. Phil Bredesen, owns the $25 million solar array and sells the electricity to VW under a 20-year agreement.
Fischer said VW's approach is to "Think Blue," referring to the strategy the German automaker uses surrounding environmental sustainability.
"This is a Think Blue plant," he said in January when the factory officially turned on the power from the solar farm.
Fischer said that when the Chattanooga plant isn't producing cars, the solar park meets 100 percent of its energy needs.
According to the EPA, VW's solar park is equivalent to avoiding the carbon dioxide emissions from the electricity use of more than 1,000 average American homes annually.