From their site: "Aeroturbines are wind turbines designed for urban settings. Invented by University of Illinois industrial design professor, Bil Becker, Aeroturbines are a new development in wind turbine technology. Aeroturbines can be installed on existing rooftops or built into the architecture of new buildings to provide clean renewable electricity at its site of consumption. Aeroturbines are uniquely suited to urban environments because they are:
- Noise and vibration-free
- Safe for birds
- Able to utilize multi-directional and gusting winds
- Self-regulating (no overspeed protection required)
- Low maintenance
- Made from low-cost and readily available materials
The structural features of the Aeroturbine allow for its easy integration into new or existing buildings: the modular/stackable cages are additive and can be mounted in a vertical, horizontal, or diagonal orientation."
These urban wind turbines basically look like a huge helix. They are apparently quiet, can be made safe for the birds, and it seems they are on track to be acceptable for zoning in many major cities due to their unobtrusive design. Check out Aerotecture International. It is the future of wind power.