NOW with Bill Moyers

Transcript - Wind Power Primer

According to the International Energy Agency, as of the year 2001, renewable energy sources (water, solar, geothermal, combustible and waste renewables, and wind) comprised 13.8 percent of the world's primary energy supply and 19 percent of all electricity production. Of that 13.8 percent, wind power accounted for only .0026 percent.

That doesn't seem like much, but wind power is one of the fastest-growing sources of energy in both the United States and abroad. While the use of renewable energy sources as a whole has annually by 2 percent since 1971, wind-power generation has increased at an average of 52.1 percent every year between 1971 and 2000.

The American Wind Energy Association estimates that an additional 6,500 megawatts of wind-energy generating capacity were added worldwide in 2001, accounting for about $7 billion in electricity sales. The U.S. alone added 1,700 megawatts worth of generating equipment.

Wind Power Plus and Minus


  • Wind energy is free.
  • It is a renewable energy resource.
  • There are no dangerous emissions.
  • Wind power can be used in remote areas.
  • Wind power can be used in conjunction with other renewable energy resources such as solar energy.
  • Wind turbines are site dependent i.e. they need to be built in areas where there is a reliable source of wind.
  • Wind speed can fluctuate. The wind speed can be too fast or slow which means that electricity is not produced.
  • Also the wind does not blow all the time.
  • Wind farms can be a visual eyesore and may create excess noise.
  • Wind turbines can be expensive to maintain.
  • Energy storage devices, e.g. batteries, are sometimes necessary.

Wind-generated power has a long history. The earliest known archeological evidence dates back to Persia in the 6th century B.C., where windmills were used to grind corn. By the 12th century, windmills could be found throughout Europe. The environmental movement and the energy crisis of the late 1970s led to a renewed interest in wind power. The United States Department of Energy now has a research office dedicated to perfecting new wind-power technologies.

Wind Turbines

"People always ask, 'Well, how do you make electricity? Where does electricity come from?' They think it comes from the electric outlet. And it's really actually not very complicated. You just need to spin a turbine. Make a turbine turn. That's how electricity's made. So, you can turn a turbine with hydropower. And you can make that steam by burning coal, or burning natural gas, or-splitting atoms. But you can also turn a turbine by putting it up on a tower in a windy place. It's a pretty simply way to make electricity."-- David Noble, Minnesotans for an Energy Efficient Economy, ME3.

A wind turbine works the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity. Utility-scale turbines range in size from 50 to 750 kilowatts. Single, small turbines, below 50 kilowatts, are used for homes, telecommunications dishes, or water pumping.
--Used with permission. For more detail please see U.S. Department of Energy, Wind Energy Program

U.S. Wind Potential Map

The potential for wind power varies throughout the United States, from region to region. However, wind potential doesn't only exist in areas like the Great Plains. The U.S. government's National Wind Technology Center shows in this map that moderate- to high-wind potential is actually dispersed throughout the lower 48 states.

Wind power ranges from Class 1 to Class 7, with each class representing wind-power density or mean wind-speed. Areas designated Class 4 or greater are suitable for advanced wind-turbine technology under development today. Class 3 areas, while generally not used for production, may be suitable for wind-power technologies in the future.

  • Power Class 1 — Purple
  • Power Class 2 — Blue
  • Power Class 3 — Light Blue
  • Power Class 4 — Green
  • Power Class 5 — Gold
  • Power Class 6 — Orange
  • Power Class 7 — Red

    --Information courtesy of the National Wind Technology Center

    Wind Power Now

    Consumption of energy grew in the 1990s, with great disparities in usage between the developed and developing world. If global energy use continues at its present rate, consumption will be double the 1998 rate by 2035, and will triple it by 2055. Electricity's share of this total will increase to 38 percent. However, even with rapid growth in wind energy production rates, by 2020 electricity production from renewable energy sources other than hydropower is projected to provide only 2.3 percent of total electricity needs. The biggest producers of wind energy are Germany, the United States, Spain, Denmark and India.

    More on estimated future world energy needs.

    Wind farms in the United States generate almost 10 billion kilowatt hours each year. That is enough to power one million average American households. The biggest wind farms in the U.S. are located in West Texas, on the Washington-Oregon border, in Kansas, and in Minnesota.