This is the VOA Special English Agriculture Report.

For centuries, farmers have used windmills to pump water, crush grain and perform other tasks. Today, farmers can earn money with high-powered wind turbines that produce electricity. Wind power has become big business, especially in Europe.

Wind turbines in California

In the United States, less than one percent of electricity is produced from wind energy. But production increased one hundred sixty percent between two thousand and two thousand five. So says Keith Collins, the chief economist at the Department of Agriculture, in a statement he prepared for a Senate committee last month.

An even greater increase is expected between two thousand five and two thousand ten. Farmers and ranchers are providing land to turbine owners or, in some cases, owning the equipment themselves.

Mister Collins says one reason for the increase is high prices for natural gas. Another is a federal tax credit for wind production. The credit is almost two cents per kilowatt hour for the first ten years of production for a project.

The production tax credit for renewable forms of energy was supposed to end this December. But Congress has extended it through two thousand eight.

Other reasons for the expansion include improved turbine technology and lower production costs. They also include policies that make it easier for wind power producers to sell their electricity. And they include the growth of markets for "green power" -- energy that does not create pollution.

California is the leading state for wind power. But Mister Collins says production is also growing in Minnesota and other Midwestern states, all the way down to Texas. And he says many states in the West and Midwest have the wind resources to produce much more wind power.

Wind power offers farmers a way to earn money for use of their land or, if they want, to operate their own turbines. Wind is free, of course. Not only that, the land under the turbines can usually be farmed. And farmers may be able to earn extra money by charging visitors to see their wind farm.

But wind farms are not perfect. Keep in mind that there has to be enough wind to earn a profit. Also, the turbines can kill birds. And people sometimes object to the development of wind farms. They consider them ugly and noisy.