The rap on wind power is that it isn’t practical. New research reinforces this belief, and suggests wind power isn’t as environmentally beneficial as claimed.
The studies, authored by Harvard researchers and published in “Environmental Research Letters” and “Joule,” examined how much land area would be required to meet future U.S. energy demands if energy production increasingly transitions to green power sources. They also examined the environmental impact of wind farms.
The land-area study concluded wind farms will need five to 20 times more land than previously estimated. This is largely because of the “wind shadow” effect. An upwind turbine reduces wind speed downwind, which means turbines must be spaced farther apart to maximize effectiveness. This factor has been ignored in many other studies on wind power feasibility.
Given the resistance of many communities to wind farms, this finding represents a significant logistical barrier to increased wind power use. While people like the idea of wind power, few are eager to have wind farms near their homes. This is true not only in conservative rural Oklahoma, but locations across the nation. Writing at City Journal, Robert Bryce notes that the Republican and Democratic gubernatorial candidates this year in “deep-blue Vermont” favored renewable energy “in principle” but opposed new wind energy development. An effort to put a wind farm offshore near Cape Cod was tied up for years due in part to opposition from local residents who objected to having turbines within sight of their homes. The opponents included former Sen. Ted Kennedy.
If smaller wind power projects draw strong local opposition, then the negative response will be exponentially greater for even larger wind farms.
What of the environmental benefit? The second study found that if you covered one-third of the continental U.S. with enough turbines to meet electricity demand, the wind farms would warm the surface temperature by 0.24 degrees Celsius. The change to nighttime temperatures was even more dramatic – up to 1.5 degrees Celsius. Those temperature changes would be caused by the fact that wind turbines mix ground-level and higher-level atmosphere while also reducing atmospheric motion.
That environmental finding is in keeping with at least 10 other studies. In fact, Harvard researchers concluded that the warming effect caused by wind turbines would be larger than any offsetting environmental benefit from reduced greenhouse gas emissions for the next century.
Study author David Keith, a professor of applied physics at Harvard, said, “The direct climate impacts of wind power are instant, while the benefits of reduced emissions accumulate slowly. If your perspective is the next 10 years, wind power actually has – in some respects – more climate impact than coal or gas. If your perspective is the next thousand years, then wind power has enormously less climatic impact than coal or gas.”
The problem for wind power supporters is that most people put more weight on immediate impact than any hypothetical impact centuries down the road. Until the immediate, negative impact of wind power projects is reduced, the industry will continue to face understandable resistance from many citizens.