Environmental Building News Says Building-Integrated Wind is Not the Answer

Thursday, April 30, 2009
CONTACT:
Jerelyn Wilson
802-257-7300 ext. 102

BRATTLEBORO, VT, April 30, 2009—Environmental Building News, the nation’s oldest and most respected publication on green building, argues in its most recent issue that putting wind turbines on top of buildings or integrating them into the building architecture doesn’t make sense. In a controversial feature article, “The Folly of Building-Integrated Wind,” executive editor Alex Wilson argues that the idea of putting wind turbines on buildings is neither technically nor economically practical.

Integrating wind turbines into buildings is appealing on a lot of levels, Wilson suggests in the article, but wind turbulence, problems with noise and vibration, and very challenging economics make successful building-integrated wind very hard to achieve. “I began my research hoping to find that this very popular green strategy made sense,” said Wilson, “but the more digging I did, the less feasible the practice seemed.”

Wilson strongly supports wind energy, but he found that turbines small enough to work on buildings are simply too expensive to compete with other, more appropriate renewable energy sources, such as photovoltaics (PV) or larger, tower-mounted wind turbines. “Large, freestanding wind turbines on ridgelines or Midwestern agricultural fields and offshore wind farms provide the most affordable renewable electricity,” according to Wilson. “It’s really hard to make the economics work on buildings.”

“The Folly of Building-Integrated Wind” describes a number of buildings that have wind power integrated directly into their architecture as well as profiling a few representative products that have been designed for rooftop installations. “Building-integrated wind is a very popular concept,” according to Wilson, “as evidenced by the wide range of turbines being introduced to tap into this market.” While actual performance data is very hard to come by, what data EBN was able to dig up showed that performance of most systems is extremely poor. Often, the rated performance of building-integrated wind turbines, especially vertical-axis machines, is based on unrealistically high wind speeds. “A turbine rated at 5 kilowatts in 32 mile-per-hour wind may only produce a few hundred watts in 12 mph wind, which will be much more commonly experienced,” says Wilson.

“The lack of consistent ratings for wind turbines and exaggerated performance claims are big problems,” notes Wilson. Indeed, some systems seem more optimized for renewable energy tax credits than for cost-effective power generation. A recent revision to federal law provides a 30% credit for small wind turbines, with no cap on the amount of the credit. The article points out that while large wind turbines provide the most cost-effective renewable electricity generation, smaller building-integrated wind turbines are usually less cost-effective than building-integrated PV systems. The installed cost of these two systems is often fairly similar, relative to the rated power output, but PV systems have a significantly higher “power factor” (the percentage of time it is operating at the rated output) in most locations, they are more reliable, and they do not require maintenance.

“The Folly of Building-Integrated Wind” was published in the May 2009 issue of EBN and is available online at www.BuildingGreen.com. While most archived content from EBN requires a membership to access, this article and an accompanying editorial are available free.

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BuildingGreen, LLC, founded in 1985, is the nation’s oldest company devoted to green building. BuildingGreen’s flagship newsletter, Environmental Building News (EBN), has been serving the building industry with objective, timely, and useful information about green building since 1992. BuildingGreen’s other publications include the GreenSpec® Directory of green building products and GreenBuildingAdvisor.com, a new website on residential green building. For information, visit www.BuildingGreen.com or call 802-257-7300.

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Editors: Alex Wilson is available for interviews about building-integrated wind. To arrange an interview, contact Jerelyn Wilson at 802-257-7300 ext. 102 or