Highways That Harvest Wind Power in Urban Environments

How many speeding cars does it take to power a lightbulb? For Mark Oberholzer, a runner-up in the 2006 Metropolis Next Generation Design Competition, this might not be such an absurd question. His project proposed integrating ­turbines into the barriers between highway lanes that would harness the wind generated by passing cars to create energy. “Opposing streams of traffic create really incredible potential in terms of a guaranteed wind source,” Oberholzer says.

His research is aptly timed—wind is rapidly gaining attention as a sustainable power source with serious potential to feed America’s insatiable appetite for energy. General Electric, a leader in the industry, is experiencing unprecedented demand for its turbines, and although North America has been slower to adopt the technology than Europe, its wind industry is growing at an average rate of about 17 percent each year. “The United States is catching up very quickly,” GE Energy’s Robert Gleitz says. “I think if the country continues to install around the rate of three or three-and-a-half gigawatts per year, it will become one of the leading countries in wind.” In response to the corresponding need for trained professionals, the School of Engineering Techno­logy and Applied Science in Toronto’s Centennial College launched the Centennial Energy Institute last October to educate students in developing and maintaining systems for power generation using the resources of the landscape.

“I’m interested in cities,” Oberholzer says of the inspiration for his design. “In Houston our landscape is highways.” The ability to harness wind in an urban environment—where buildings impede airflow and installing 260-foot turbine towers isn’t exactly an option—makes his project particularly inventive. “There are places where it simply makes sense to employ a renewable,” says Herb Sinnock, an energy ­specialist at Centennial. “The idea is to do that wherever possible. If we take those smaller contributions and add them up, we take a big chunk out of our energy-supply problem.”

Still in the research phase, Oberholzer has evolved his concept to harvest more energy. While his original proposal suggested a single row of vertical-axis rotary turbines, he’s recently discovered that double-stacked Darius turbines will capture the wind from both directions more efficiently. With this refinement, each barrier now “packs much more generating power.” Likewise, he has adapted the scheme to better address the challenges of distributing energy. “The technical problems of tying into the grid and managing the flow made me think of putting the power to a different use,” he says. “I’m pretty excited about integrating a subway or light-rail train right where the barrier is. I love the idea of siphoning off electricity generated by private transportation to run public transportation.” Using the power where it’s generated, rather than redistributing it through the grid, avoids energy losses that occur during transportation and eliminates the cost of adding extra infrastructure. “Certainly having them closer to where you actually use the electricity is very helpful,” says Christine Real de Azua of the American Wind Energy Association.

Oberholzer’s model benefits from the urban schedule as well as its urban location. “The peaks of traffic flow more or less coincide with those of energy use,” he says, suggesting that rush-hour chaos on the highways could actually help power the commute for public-transport users. Given the opportunity to prototype his turbine barriers, Oberholzer just might put a positive spin on our busy roadways.