The problem with erecting wind turbines in big cities and other urban areas come down to several factors: size and noise, zoning laws, wind variability and intermittency, bird safety… But thanks to some new innovations,  urban communities and a couple of “small wind” startups are poised to bring renewable energy to town squares and apartment complexes.

New Scientist brings us news of some exciting advances in small wind, including work inspired by fish tails from Ephrahim Garcia, a mechanical engineer at Cornell University in Ithaca, New York. Instead of a mechanical turbine, Garcia “attached a flexible aerofoil to the end of a pole made out of a piezoelectric material. When air passes over the aerofoil it flutters, causing the pole to flex and generate a small alternating current.” Neat!

Not only could such a method remove a lot of the stigma of having big noisy blades slicing the air above rooftops, it could potentially solve the problem of drawing power from cities where buildings and streetscapes interrupt the smooth flow of air. According to the researchers at Cornell, cities have plenty of wind to harvest, they just require new ways of thinking. Garcia’s method looks like it fits the bill.

In Alex Salkever’s Yale 360 report on small wind’s ascent, he mentions Hawaii’s Humdinger Wind Energy, which is also betting on piezoelectrics as a means to fuel the market for compact wind energy systems. However, a startup from Michigan called Windtronics isn’t giving up on blades to capture wind energy. Instead of merely down-sizing turbines and perching them on buildings, the company’s windmills generate power at the blade tips, or the outer circumference rather than a central rotor and generator assembly. What results is a compact, bird-friendly and semi-enclosed unit that produces no noise and no vibration, according to the company. In other words, perfect for adding some renewable energy sources to your mid-rise office tower.

One great thing about these systems is that they should breeze past zoning and safety requirements in all but the most stringent areas. That they are designed to be immune to NIMBYism is also a big plus.

Image: Terry Wha – Flickr – CC