In a speech in Santa Barbara, Calif., McCain (R-Ariz.) vowed to “put the purchasing power of the United States government on the side of green technology” by buying fuel-efficient vehicles for its civilian fleet of cars and trucks and by retrofitting federal office space. The pledge comes months after Obama (D-Ill.) outlined a more detailed and ambitious proposal on the subject, virtually ensuring that the next administration will take significant steps to lower the government’s output of energy and pollution.

A greening of the government would probably have a major impact on the Washington region, as the modernizing of buildings would spark a mini-construction boom and ease energy demands. Cleaner vehicles would also reduce harmful auto emissions, environmentalists say.

Saying that the U.S. government ranks as “the single largest consumer of electricity in the world” because it holds sway over “3.3 billion square feet of federal office space” worldwide, McCain said he plans to reduce the government’s carbon footprint by updating its buildings and demanding better standards in new ones.

“By retrofitting where possible, and by applying a higher efficiency standard to new buildings leased or purchased, we can save taxpayers billions of dollars in energy costs and move the market in the direction of green technology,” he said.

McCain did not provide details about his plan, causing some public watchdog and environmental groups to question how much energy would be saved.

As with most proposals by politicians specifics are few and far between.  It is a grand plan, but how will he pay for this proposal?