When we think about wind energy we usually imagine giant turbines in the rolling hills and expansive plains of rural America. But what about building turbines right into our cities?
Instead of creating urban wind power by just placing a few desultory turbines on the top of a skyscraper, a new, more exciting experiment in urban wind-energy is about to commence in San Francisco. When the new headquarters building for the San Francisco Public Utilities Commission opens in the fall of 2012, it will have a unique feature: a column of wind turbines stretching up one side of the 13-story structure behind a glass-paneled face. This wind-energy "wing"—the first of its kind—will house three to five energy-generating turbines, providing at least 7% of the building’s energy needs. The curvature of the building’s side is designed to enhance the speed of the wind.
The novel design was developed with the help of Bruce White and Case Van Dam, two engineers from the UC Davis Wind Energy Collaborative. White has been studying the wind in San Francisco for years (he advised on the orientation for AT&T Park, where the Giants play). This site, he says, is particularly good for urban turbines. "Tenth and Market is known to be one of the windiest areas in San Francisco," White said, because three nearby high-rises funnel wind through the intersection.
In addition to the wind-energy wing, the PUC headquarters will have a gray-water recycling system, extensive day-lighting features, a "solar chimney" ventilation system, and solar panels. The building is expected to use about half as much water and 32% less energy than a comparable office building.
A handful of other integrated wind-generation systems are already functioning in other parts of the world. The Bahrain World Trade Center has three blades suspended between its two towers. The Strata SE1 skyscraper in London has three turbines built into the top. But integrated wind-energy systems are still very rare. If this new building’s system proves successful, it could serve as an important proof-of-concept for other urban wind-generation projects.