Wind machines have changed dramatically from those that were common in the 1800s. Early windmills produced mechanical energy to pump water and run sawmills. In the late 1890s Americans began experimenting with wind power to generate electricity. Their early efforts produced enough electricity to light one or two modern light bulbs.
Compared to the pinwheel-shaped farm windmills that can still be seen dotting the American rural landscape, state-of-the-art wind turbines look more like airplane propellers. Their sleek, high-tech aerodynamics and fiber-glass design allow them to generate an abundance of electricity, while they also produce mechanical energy and heat. (See Figure 10.10.)
Unlike solar energy systems, wind systems produce renewable energy at night as well as during the day. During the 1990s industrial and developing countries alike began using wind power as an adaptable source of electricity to complement their existing power sources and to bring electricity to remote regions. Wind turbines cost less to install per unit of kilowatt capacity than either coal or nuclear facilities. After installing a windmill there are few additional costs, particularly as the fuel (wind) is free.
Wind speeds are generally highest and most consistent in mountain passes and along coastlines. Europe has the greatest coastal wind resources, and clusters of wind turbines, or wind farms, are being developed in much of
FIGURE 10.10
Horizontal axis wind turbines are used to create energy on a wind farm in Altamont Pass, California. (Photograph by
Energy Production by Wind Turbines
Wind is the world's fastest growing energy source. According to the American Wind Energy Association, worldwide capacity at the end of 2003 was approximately 39,000 megawatts, up 26 percent from the year before. Europe generated almost three-quarters of the world's wind power. U.S. capacity at the end of 2003 was 6,374 megawatts, accounting for 16 percent of the total. Nearly 1,700 of those megawatts were added during 2003.
The wind industry in the United States began with research projects in California. In 1981 the state erected 144 relatively small turbines capable of generating a combined total of 7 megawatts of electricity. Within a year the number of turbines had increased ten times, and by 1986 had multiplied 100-fold. The 1980s saw an explosion of wind technology in California. By 1995 the state produced enough wind power to supply all of San Francisco's residents. Experts point out that California's dominance had less to do with wind availability than tax credits that were offered by the state until 1999. Approximately 32 percent of the total 6,374 megawatts of installed wind power capacity in the United States was located in California at the end of 2003. (See Figure 10.11.)
During the 1990s wind energy facilities began to appear in other states, particularly in the Midwest. Texas now supplies 20 percent of the nation's wind power capacity, thanks to legislative policies that require the state's utilities to provide renewable generating capacity. Together, California and Texas generate more than half of the country's wind power.
FIGURE 10.11
United States wind power capacity, 2003
Studies show that several states, especially the plains states, have wind speeds sufficient to supply electricity. Twelve states—North Dakota, South Dakota, Texas, Kansas, Montana, Nebraska, Wyoming, Oklahoma, Minnesota, Iowa, Colorado, and New Mexico—contain 90 percent of the U.S. wind energy potential. Refinements in wind turbine technology may enable a substantial portion of the nation's electricity to be produced by wind energy.
Problems in the U.S. Wind Industry
Wind energy capacity grew very slowly until the late 1990s, adding less than 300 megawatts of capacity between 1990 and 1998. Crude oil prices fell during this time, making oil and gas the lowest-cost fuel sources. Concern about reducing the federal budget resulted in a change in federal policy toward renewable energies. Furthermore, some people were concerned about the uncertainty involving electric utility deregulation. U.S. producers received around $.03 to $.04 per kilowatt-hour in price guarantees while wind producers in Germany, Denmark, and India were guaranteed more than twice that amount. As a result investors often found investing in wind energy in the United States too risky. However, the tide began to turn in the late 1990s. Between 1999 and 2003 the country's wind generating capacity expanded at an average rate of 28 percent annually.
Development of Wind Energy throughout the World
During the decade following the 1973 oil crisis, more than 10,000 wind machines were installed worldwide, ranging in size from portable units to multi-megawatt turbines. In developing villages small wind turbines recharge batteries and provide essential services. In China small wind turbines allow people to watch their favorite television shows, a major reason for the increased demand for turbines in China.
Although wind power supplies less than 0.1 percent of the world's electricity, it is one of the fastest growing energy sources. The most ambitious wind energy program is planned for India, which expects to provide enough electrical power to serve 5 million customers. India is expected to be the most rapidly growing market for wind turbines and, if the planned program is successful, wind may supply more energy for India than the country's nuclear program.
Interest in wind energy has been driven in part by the declining cost of capturing wind energy—from more than $.25 per kilowatt-hour in 1980 to $.05 per kilowatt-hour for new turbines in the late 1990s. This makes wind power nearly competitive with gas- and coal-powered plants, even before considering wind's environmental advantages.
Encouraged by improved technology, falling costs, and government incentives like tax credits and guaranteed prices, wind power is booming across Europe. One reason for the growth in the industry is that the European Union wants to diversify its energy sources while clamping down on pollution. Almost no country supports the expansion of nuclear power and, in many areas, wind power is becoming economically viable.
Wind energy is produced under entirely different circumstances in the United States than in Europe. American entrepreneurs, seeing wind energy as a potentially profitable business, built large wind farms with huge numbers of turbines. When oil prices fell and tax credits were cut, growth stalled. In Denmark, Germany, Sweden, and the Netherlands, wind energy began as a grassroots movement, with small groups of politically motivated investors installing one or a few machines at a time. In Spain, Britain, and Greece, the clusters were larger because money was provided by local governments and utilities. The latest trend in Europe is to build wind farms offshore where there is more wind and fewer complaints that they clutter the landscape.
Advantages and Disadvantages of Using Wind Energy
The main problem with wind energy is that the wind does not always blow. Some people object to the whirring noise of wind turbines or do not like to see wind turbines clustered in mountain passes and along shorelines because they interfere with scenic views. Some environmentalists have charged that the wind turbines are responsible for the loss of some species of endangered birds that fly into the blades. Finally, as with all types of renewable energy, wind power is more expensive to produce than energy generated through conventional means, at least when the price of oil remains low.
On the other hand, generating electricity with wind offers many environmental advantages. Wind farms do not emit climate-altering carbon dioxide, acid rain–forming pollutants, respiratory irritants, or nuclear waste. Because wind farms do not require water to operate, they are especially well suited to semiarid and arid regions. Wind farming also offers the added benefit of reducing soil loss on land prone to wind erosion because turbines capture the wind and decrease its potential for downwind destruction.
User Comments Add a comment…