The search for accessible, renewable energy has reached a fevered pitch, and one of the leading candidates to potentially replace fossil fuels is also one of the oldest -- wind. It's been harnessed for centuries to mill grains and power ships, and as far back as the 1930s it's been used to generate electricity. But over the past 40 years, as demand for and the price of energy has steadily increased, so too have the efforts to turn wind into a viable option for producing electricity on a large scale. The potential of wind turbines, which convert kinetic energy into electrical energy, has been promoted at every turn. But what about the risks? After all, these wind turbines can be colossal, measuring more than 400 feet (122 meters) tall, weighing in at close to 400 tons, and equipped with rotating blades that may span 300 feet (91 meters) or more. And even the most ambitious plans from the U.S Department of Energy aim to supply just 6 percent of the nation's electricity from wind by the year 2020. So, it is worth the risks?
First, let's look at some of the financial risks of wind energy. Subsidies and incentives offered by the government are creating a sense of urgency for utility providers and co-ops to install wind farms. But even with the financial breaks, wind energy is a cost-intensive operation. According to the American Wind Energy Association, constructing a 50 megawatt wind farm (around 25 wind turbines) carries an up-front cost of around $65 million, and that's before a single kilowatt of electricity is generated. That's a pretty steep price tag for a venture that rests completely on something as unpredictable as the wind.
Another risk associated with wind farming is blighting the landscape with acres upon acres of massive turbines. The same hypothetical 50 megawatt wind farm we just discussed, for example, would require nearly 4,000 acres (16 square kilometers), or around 150 acres (0.6 square kilometers) per turbine. So even in areas that are relatively isolated, these installations can turn an otherwise pristine desert mesa into an industrial eyesore. And because sweeping mountain ranges and breezy coastlines are ideal locations for both wind farms and tourists, communities including Nantucket Sound are resisting wind farm development out of fear that visitors will opt for other destinations.
In the next section, we'll explore some of the risks wind farming poses to the environment as well as to people.
Physical Risks Associated with the Production of Wind Energy
Wind turbines can also cause actual bodily harm, both to humans and wildlife, in areas around installation sites. From a distance, the blades seem to move slowly but the tip speed on these turbines can approach 200 miles per hour, creating deadly obstacles for birds. Birds of prey are particularly vulnerable since they hunt in open plains where visibility is high. One particularly highly publicized wind farm, Altamont Pass in California, has been a lightning rod of controversy because of the impact poor planning has had on the bird population. According to the Center for Biological Diversity, as many as 1,300 eagles, falcons, hawks and other predatory species are killed each year because the wind turbines were constructed along a critical migration route.
People are also at risk. As with any developing technology, progress and understanding usually happen simultaneously. Blade throw, although it's rare these days thanks to design improvements, is a malfunction that occurs when a blade breaks free of the turbine and becomes a very large, very dangerous projectile. Similarly, wind farms that operate in cold climates are also susceptible to ice formation. Accumulating ice can fall or be thrown from turbines, potentially endangering surrounding people and property.
There are also more subtle health risks of wind farming. In her book, "Wind Turbine Syndrome: A Report on a Natural Experiment," Dr. Nina Pierpont describes a condition called "wind turbine syndrome" in which wind farms pose actual health risks to nearby residents. The sub-sonic noise generated by turbines is believed to cause maladies ranging from headaches and sleeplessness to dizziness and even depression. And visually, the flicker effect of spinning turbines can cause vertigo and even seizures.
For all its promise, wind energy is not without its own set of risks that should be weighed against the benefits. After all, it wasn't that long ago that petroleum was hailed as a cleaner, more efficient alternative to coal and helped power the world through the industrial revolution.
- American Wind Energy Association. "Wind Energy Basics." (June 14, 2010) http://www.awea.org/faq/wwt_basics.html
- Center for Biological Diversity. "Fact Sheet on Altamont Pass Bird Kills." (June 12, 2010) http://www.biologicaldiversity.org/campaigns/protecting_birds_of_prey_at_altamont_pass/pdfs/factsheet.pdf
- Dyer, John. Boston Globe. "Community debates $3b Cape Wind deal." (June 17, 2010) http://www.boston.com/business/articles/2010/06/17/community_debates_3b_cape_wind_deal/
- DTE Energy. "Renewable Energy Electrical System." (June 13, 2010) http://www.dteenergy.com/wind/pdfs/electricalSystem.pdf
- Larwood, Scott. National Wind Watch. "Permitting Setbacks for Wind Turbines in California and the Blade Throw Hazard." (July 30, 2008) http://www.wind-watch.org/documents/permitting-setbacks-for-wind-turbines-in-california-and-the-blade-throw-hazard/
- Pierpont, Nina. "Wind Turbine Syndrome: A Report on a Natural Experiment." K-Selected Books. 2009.