PIERRE, S.D. — Plans for the world's largest wind farm, proposed to be built in South Dakota, have become more grandiose.

PIERRE, S.D. — Plans for the world's largest wind farm, proposed to be built in South Dakota, have become more grandiose.

South Dakota is officially rated No. 4 in the nation for the potential capacity to make electricity from wind, although the ranking is more than a decade old. Many industry officials believe the Great Plains state is the windiest of all.

Clipper Windpower of Carpinteria, Calif., intends to erect enough wind turbines in several South Dakota counties to produce up to 6,000 megawatts of electricity, said Bob Gates, the firm's senior vice president of commercial operations.

That would be eight times larger than the biggest wind farm in the world, a 735-megawatt FPL Energy facility with 421 turbines stretching across three Texas counties.

Clipper Chairman and Chief Executive Officer James Dehlsen told The Associated Press in 2004 the company intended to develop a $3 billion wind complex with 1,000 turbines that could produce 3,000 megawatts of juice in South Dakota.

But as envisioned now, the project would be twice as large and cost $6 billion, Gates said.

Taking into account that the wind doesn't always blow or is too light or strong at times to operate turbines, a 6,000-megawatt wind farm could supply enough power for an average of about 1.6 million homes, based on data from the American Wind Energy Association.

Clipper makes 2.5 megawatt turbines, and it would take 2,400 of them to produce 6,000 megawatts of electricity. However, the firm continues to develop more efficient turbines and is part of a project to build 7.5 megawatt turbines for an oceanic wind farm off the coast of Britain.

Clipper officials are not saying exactly where the proposed mega complex will be located in South Dakota, but they indicate it will be built in stages.

"I think each stage would eclipse the size of the previous one," Gates said.

If Clipper can find a buyer for the electricity, the project could get under way in a couple of years, he said.

Huge amounts of extra electricity cannot be moved out of South Dakota until more transmission lines are developed, however.

"To do big-time wind, you need to put in upgraded and new transmission capabilities," Gates said.

Gates, president of the American Wind Energy Association, met recently with Sen. John Thune, R-S.D., about the future of wind development in the nation.

Thune hopes an energy bill pending in Congress will extend a federal tax credit for the wind industry. The incentive of 1.9 cents per kilowatt hour, initially approved in 1992, is to expire at the end of the year.