Commercial buildings that incorporate wind power turbines into their construction are rare, but new research conducted by a group of Texas college students could encourage more commercial building companies to adopt the technology into their designs as a way to help cut electricity costs.
A group of three seniors from the University of Texas at Austin mechanical engineering program recently completed a two month study on the effectiveness of building-mounted wind turbines for Building Turbines Inc., an Austin-based developer of rooftop wind turbine systems.
The students collected data on two wind turbines, one with a traditional vertical orientation, called a vertical-axis wind turbine, and one with a horizontal orientation, called a horizontal-axis wind turbine. The students measured the amount of electricity generated at various wind speeds and directions and found that the horizontally-oriented turbine outperformed the vertically-mounted turbine.
The results of the students’ research could pique the interest of the small, but growing market of wind-power integrated commercial buildings in the United States. Manufacturers have struggled so far to come up with a way to make vertical-axis turbine systems attractive enough for widespread adoption. Issues and perceptions related to the cost and performance of the technology — and the necessity of high winds — are likely key reasons why only a handful of U.S. buildings have been designed to accommodate wind power turbines in their construction.
An early example of the incorporation of vertical-axis wind turbines in the design of U.S. commercial buildings is Greenway Self Park, a parking garage in downtown Chicago that was completed in the fall of 2009. Self-billed as “Chicago’s first earth friendly parking garage,” Greenway Self Park integrated 12 vertical-axis wind turbines into the beveled southwest corner of the building. The turbines, which cost about $16,000 each, can start generating electricity in 11.1 miles per hour wind — perhaps not a challenging milestone in the Windy City. Under ideal conditions, each turbine can generate up to 4.5 kilowatts of electricity. The turbines, which together cost almost $200,000, were designed to generate enough electricity to cover the building’s exterior lighting costs.
Most recently, vertical-axis wind turbines have made their way into the design of a San Francisco skyscraper set to open next fall. The building, which is located near the famously windy intersection of 10th Street and Market Street, will be the new headquarters of the San Francisco Public Utilities Commission (PUC). It was developed with the help of engineering professors from the University of California, Davis, and incorporates a “wing” of wind turbines that stretches all the way to the roof. The turbines, fed by wind funneled by three nearby high-rises, will produce at least 7 percent of the building’s energy needs.
Bruce White, professor of mechanical and aerospace engineering and former dean of the UC Davis College of Engineering, said that the PUC’s new building could be a model for effectively integrating wind-energy devices in high-rises. White said that although the wind environment in urban settings doesn’t produce the same power efficiencies as rural wind farms — even in windy cities like San Francisco and Chicago — the most important factor in urban environments is the ability for a building to generate and use its own power and, therefore, not have to rely as much on an electric utility.
According to White, integrating wind power into the design of urban buildings will allow building owners to be one-third as efficient as a wind farm and still be economically feasible. White agreed that horizontal-axis wind turbines could outperform traditional vertical-axis turbines, but noted that their use could increase bird strikes, a political issue in San Francisco that might keep more developers from adopting integrated wind power in commercial building designs.
“UT Austin Mechanical Engineering Students Complete Design Study,” Building Turbines Inc. press release, Nov. 29, 2011.
“Wind Experts Advise on Revolutionary Wind-Powered Skyscraper,” University of California, Davis press release, Nov. 17, 2011.
“Building Integrated Wind in Chicago,” Jetson Green, Jan. 20, 2011.