Harnessing the Power of Wind
BY AWAKE! CORRESPONDENT IN THE NETHERLANDS
ROUND and round the huge rotor blades turn. They revolve slowly, steadily, like the arms of a giant swimmer who labors tirelessly against a current that forever holds him in place. These arms, though, move because of the current—not in spite of it. The current is the wind. Aside from its rustling, the whirring of these mechanical arms is the only sound to be heard. This is a wind turbine, generating electricity from wind power.
In windswept parts of such countries as Denmark, France, Germany, the Netherlands, and the United States, more and more of these wind turbines dot the landscape. In the United States, California already has more than 16,000 of them. Some 30 miles [50 km] east of San Francisco, at Altamont Pass, there is a wind farm where some 7,000 turbines crowd the hillsides to draw power from the steady wind. Altogether, California’s wind turbines are said to be capable of generating enough power to supply the residential needs of San Francisco and Washington, D.C., combined.
Denmark, surrounded by the sea, is also well suited for harnessing wind energy; already there are some 3,600 wind turbines there. In 1991 the Netherlands had only about 300 wind turbines, but the country’s windiest provinces agreed to increase that number to 3,000. Energy planners in England too are hoping to harness the wind to a similar extent in their country.
Of course, harnessing the power of the wind is not a new idea. Just think of all the ships driven by the wind that sailed the oceans during the ages before the advent of engines. Windmills have been used for centuries to pump water, to grind corn and spices, and to saw wood. In the Netherlands there are about 900 of these graceful monuments left. Many of them are still faithfully pumping water; they are reliable even during power outages.
It was a century ago that Danish professor Poul de la Cour first experimented with harnessing wind power to generate electricity. He developed a small forerunner of today’s modern wind turbine. However, in the 20th century, mankind found that fossil fuels were much easier to harness and provided greater power. At first, such fuels seemed cheap and plentiful; so they easily eclipsed the wind as a source of power. It was not until the oil crisis of 1973 that wind power was again taken seriously.
Advantages for the Environment
The oil crisis prompted scientists to consider what would happen when fuel supplies were exhausted. Alternatives such as wind power took on a new appeal. Wind, after all, is inexhaustible. In effect, it renews itself constantly, much as the Bible said of it: “Round and round it is continually circling.” (Ecclesiastes 1:6) Wind power is also much easier on the environment than fossil fuels, which contribute to fearful phenomena such as acid rain and may intensify the greenhouse effect. Wind energy produces no chemical emissions whatsoever.
And while wind is not as concentrated a form of energy as gas, coal, or oil, it has surprising advantages. For example, picture a wind turbine turning slowly in a gentle ten-mile-an-hour [10 km/hr] breeze. Suddenly the wind picks up, doubling to 20 miles per hour [20 km/hr]. How much more energy is the turbine now drawing from the wind? Double the amount? No. New Scientist magazine explains: “Wind energy varies as a cube of the wind speed.” So when the wind speed doubles, it provides eight times the power! Even a small increase in wind speed thus means a large boost in energy output from a wind turbine. To take full advantage of this cube law, as it is called, wind turbines are commonly placed on hilltops, where wind accelerates as it rushes over.
Another appealing aspect of wind power is that it is a fairly decentralized system. A windmill can bring the source of energy close to the user. The machines are quick to install and easy to move. Wind is not mined, shipped, or bought. This means that the power is not difficult to distribute, especially compared to crude oil, which has to be shipped in large bulk carriers. Accidents involving such carriers have led to enormous environmental disasters time and time again—such as the Alaskan oil spill of 1989. Wind turbines have no such disadvantages.
Some Drawbacks
This does not mean that wind power is a panacea for mankind’s energy problems. One major challenge lies in the unpredictability of the wind. It can change direction at any time. Researchers have long looked for solutions to this problem. One answer was devised in the 1920’s, when the French engineer Georges Darrieus developed a wind turbine with a vertical axis. It looks much like a huge mixer, and it operates regardless of the direction of the wind. Variations of this odd-looking contraption are in operation today. However, wind can also stop altogether at any time. And at the other extreme, sudden gales can damage the rotor blades and turbine.
Surprisingly, some of the most vocal objections to the use of wind power concern the environment. For one thing, the high-tech wind turbines of today are a far cry from the picturesque, quaint structures of yesteryear. The large ones are as much as 300 feet [100 m] tall; the medium ones 130 feet [40 m]. Few would describe them as pretty. True, many high-tension lines and radio towers may be that tall, but the whirling blades of a wind turbine draw a good deal more attention.
Then there is the matter of noise. Some object strenuously to having wind turbines in their vicinity because of the noise that they generate. Yet, interestingly, one study found that a medium-sized turbine in Cornwall, England, produces about the level of noise you would hear if a car traveling at 40 miles per hour [60 km/hr] passed 20 feet [7 m] away from you. This sound level drops dramatically with distance though. A person 1,000 feet [300 m] away hears no more noise than he would hear in an average library. What is more, the wind that makes the turbine spin tends to mask the noise. Admittedly, however, when there are hundreds of wind turbines at one location—or thousands as there are at California’s Altamont Pass—noise can be a significant problem.
Another problem involves birds. A bird protection organization in the Netherlands recently warned against building wind farms where birds feed and breed—when it is dark or foggy outside, they might crash into the rotor blades. According to one estimate, on a Dutch wind farm with 260 turbines, up to 100,000 birds a year could be killed in this way. However, other studies indicate that wind turbines have little effect on bird life.
An Insurance Policy?
Despite these obstacles, it is clear that wind power can make an important contribution to reducing world consumption of fossil fuels. In his book Wind Energy Systems, Professor Gary L. Johnson of Kansas State University, U.S.A., explains that wind power could work together with more conventional generation systems. Used in that way, he says, “wind generators may be considered as somewhat of an insurance policy against serious fuel supply problems.”
Before long, man may be in sore need of such an insurance policy. The news media often mention man’s endless quest for fuel. As he mines for coal and drills for oil and gas, he not only depletes these irreplaceable commodities but in some places also fouls his own nest by putting them to use! Meanwhile, the wind blows on—clean, endless, and, for the most part, still ignored.
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Thousands of wind turbines generate electricity in many countries
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Hundreds of these graceful monuments are still left in the Netherlands