To talk to T. Boone Pickens, you wouldn’t know he’s faced a significant setback—the delay of plans to build the world’s biggest wind farm.

This man, one of the most well-known figures in the energy business, is an optimist. He’s optimistic about what he’ll do with the $2 billion worth of turbines he’s already ordered for the 4,000-megawatt project on the Texas Panhandle that’s been put on hold. And he’s optimistic about his plan to use natural gas and wind power to wean the United States from foreign oil.

“I’m on the hook for those turbines, so I’m in the wind business,” says the oilman and hedge fund manager turned wind farmer. Pickens says he might get to use them in the small town of Pampa, Texas,(See correction at the end of the story) but he vows to put those 667 turbines to work somewhere when General Electric delivers them in 2011. “We’re looking at deals in Wisconsin, Alberta. We’ll get it done. You don’t have any choice. You go ahead with the projects.”

Putting the wind farm on hold hasn’t changed Pickens’ commitment to his crusade against non-U.S. oil. In July 2008, as gasoline prices soared above $4 a gallon, Pickens introduced his plan to populate one of the richest wind corridors on earth—from West Texas to the Dakotas—with wind farms. Electricity from those farms would replace natural gas in the nation’s utility mix. Then, natural gas would be used primarily in transportation, especially for large trucks that now run on diesel fuel.

Pickens’ blueprint is worth revisiting now as world leaders gather, first in New York for a United Nations climate-change conference and the opening of the U.N. General Assembly, then in Pittsburgh for the G-20 summit of the world’s biggest economic players. On Tuesday, President Obama singled out wind-energy projects as a key component to the future. “We understand the gravity of the climate threat. We are determined to act. And we will meet our responsibility to future generations,” Obama said.

While Pickens has said his plan primarily is about getting rid of foreign oil, it also has the side effect of being more environmentally friendly than the nation’s current energy mix. Natural gas burns cleaner than diesel, and wind power produces no greenhouse gasses.

Skeptics have said that Pickens, who sits on the board of Clean Energy Fuels—the largest distributor of natural gas for transportation in North America—and is in the wind business, came up with his plan to turn a profit. He has responded that, yes, he could make money if his plan became a reality. But his real motivation, he has said, is patriotic—he doesn’t want his nation addicted to foreign oil.

“We’re just a sitting duck,” he says. “We just say send us the oil, never mind the price.”

Natural gas and wind are both plentiful in the United States—the nation produces 92 percent of its own natural gas, and imports the other 8 percent from a friendly nation, Canada, said Fadel Gheit, an energy analyst with Oppenheimer & Co.