Going Green: The Air Force increased the amount of energy that it purchased late last year from environmentally friendly renewable sources, making it now the nation’s third largest consumer of them, the Environmental Protection Agency announced on Tuesday in its quarterly list of the Top 25 green power purchasers for the period ending on Jan. 8. "This increased purchase further demonstrates the Air Force's commitment to protecting the environment and builds upon its existing partnership with EPA’s Green Power Partnership," the service said in a statement issued on Feb. 19. USAF also continues to stand at the top of the list of organizations within the federal government that purchase energy generated from sources such as biogas, biomass, geothermal, solar and wind, EPA said. The Air Force buys more than 899 million kilowatt hours of green power annually, enough to meet approximately nine percent of its purchased electricity use. According to the EPA, this amount is enough to power nearly 90,000 average American homes annually. Or, viewed from another perspective, since green power has a net impact of zero on the environment in terms of carbon emissions, this is the equivalent of avoiding the carbon dioxide output from more than 128,000 passenger vehicles per year, according to USAF. Fifty-four Air Force bases, in addition to numerous Air Force Reserve and Air National Guard facilities purchased renewable power in Fiscal 2007, including Minot Air Force Base, N.D. and Dyess AFB, Tex., both of which bought 100 percent of their electricity from renewable sources. USAF said.