T Boone Pickens is famous for thinking big. He founded his Texan oil company, Mesa Petroleum, in 1956 with just $2,500 (£1,200) in the bank. After a string of audacious takeovers he turned it into an independent empire that challenged the big oil companies, and today he is worth $3bn.

Now this straight-talking Southerner is launching the biggest and most audacious project of his career. This month he will make the first down payment on 500 wind turbines at a cost of $2m each. The order is the first material step towards his goal of building the world's largest wind farm.

Over the next four years he intends to erect 2,700 turbines across 200,000 acres of the Texan panhandle. The scheme is five times bigger than the world's current record-holding wind farm and when finished will supply 4,000 megawatts of electricity - enough to power about one million homes.

It's not just the breathtaking scale of the scheme that is striking, though at a total cost of $10bn it impresses even Pickens himself: "It's pretty mind boggling," he says. The fact that Pickens, a tycoon who made his fortune in oil, has turned his attention to wind power is an indication of how the tectonic plates are moving. Until recently wind was seen as marginal and alternative; now it is being eyed by Wall Street.

"Don't get the idea that I've turned green," Pickens tells the Guardian in the Dallas offices of his new venture Mesa Power. "My business is making money, and I think this is going to make a lot of money."

His fascination with wind developed as Pickens engaged in his favourite leisure pursuit - quail hunting. For years he has been shooting Bobwhite quail on his 68,000-acre ranch in the panhandle. "I've been hunting quail for 50 years, I know where the wind is," Pickens says.

The idea formed that this area of Texas, with its wide-open space, low population and steady south-westerlies would make a perfect location for wind-generated energy. Studies proved him right - there was more wind than even he had imagined, much of it at peak times in the middle of the day when power sells at a premium.

So he set about convincing neighbouring ranchers to join his scheme, promising them between $10,000 and $20,000 in annual royalties for every turbine they allowed on their land. They have all signed up, eager to cash in on this literal windfall. (Pickens, by contrast, refuses to have any of the turbines placed on his own ranch. "They are ugly!" he says, unashamedly.)

To see exactly what the promise is to ranchers and rural communities of the new dash for wind, you have to drive four hours west of Dallas into the Texan prairies. Until a couple of years ago Sweetwater was a gently declining railroad town, its population falling year on year and its infrastructure quietly rotting. Now it is a boom town, a 21st-century equivalent of the Wild West. German wind technicians who have poured into the area have coined a name for it - the Wind West.

The three largest wind farms in America are all situated in the surrounding area, Nolan county, which, with a population of just 18,000, now produces more wind power than the UK, France and California.

While other towns in the region are struggling with plummeting house prices and job losses, Sweetwater is in the midst of a construction explosion. Two new companies opened this week, one servicing the blades of the county's 2,000 turbines, another renting out cranes used in erecting new turbines. The turbines, state of the art models 400 feet to the tip of their blades, span out for 150 miles in any direction.

New roads and houses are going up, and local schools and medical centres have been renovated using the influx of tax revenues from the energy companies. Greg Wortham, Sweetwater's mayor, says he has watched over the past two years as wind power was transformed "from a hobby - a green thing - into an industry. Suddenly it was all about welders and engineers and truckers. We have companies here begging for new workers and paying them more than the thousands being laid off by the car companies."

Back in Dallas, Pickens believes there are several reasons to invest in this new energy source. Beyond the mere profit motive, which clearly excites him, there is the fact that Texan oil has been on the wane since it peaked at 10m barrels a day in 1973, and is already down to half that amount. "Oil fields have a declining curve - you find one, it peaks and starts downhill, you've got to find another one to replace it. It drives you crazy! With wind, there's no decline."

There is also a political edge to his obsession. Politics and Pickens go together, as is obvious from the walls of his offices, lined with photographs of him with world leaders. One shows him with the Queen, Prince Philip and George HW Bush; another is with Margaret Thatcher and Ronald Reagan; a third shows him on board Air Force One with the current President Bush. There is a signed calendar from Arnold Schwarzenegger on the table.

As the pictures suggest, Pickens has for many years been a major financial backer of both George Bushes, but he professes to be frustrated by the lack of action on energy by this administration and all its predecessors. "George Bush has done nothing. Nothing. Every guy that ran for president clear back to Nixon said he would make us energy independent, but not one goddamned thing has been done. Zero. The biggest problem facing the United States in the next 50 years is energy and nobody has come up with a solution."

Pickens, being Pickens, has come up with a solution - and it makes his own gargantuan plans for a wind farm in the panhandle look tiny. For the benefit of the Guardian, he draws on a white board his master scheme. He carves out an enormous corridor of land running north to south through the middle of the US - along the great plains - where he would build an army of wind farms. Then he draws an equally enormous corridor running east to west from Texas to southern California which he would similarly dedicate to solar energy.

"You need a giant plan for America. Not the pissant 83 megawatt [windfarm] deals being stamped all over the country. There needs to be a huge plan from someone with leadership. It's going to take years to do, but it has to start now." Only then, he explains, can the US stop what he regards as the madness of a flood of money flowing out of America to the oil producers of the Middle East. "That money is going God knows where - a few friends, a lot of enemies. We've got to stop it."

T Boone Pickens certainly is thinking big. And all this as he prepares to celebrate his 80th birthday next month. How is it that he appears to be expanding his ambitions at a stage in life when most people are retrenching theirs? "You're getting older so you are running out of time," he says. "So let's go! We haven't got long, and we've got to get this job finished."