Urban Wind Power Generation Using Modified Wind Turbines
Urban wind power harvesting methods have not worked well in the past, but a new generation of wind turbines promises to change everything
With the worldwide movement to find alternative energy sources in full bloom, researchers at Cornell University’s Laboratory for Intelligent Machine Systems (LIMS) are challenging the myth that urban wind power offers speeds too low to be effective. The research team lead by Ephraim Garcia is attempting to re-invent the wind turbine for urban wind power generation.
The methods used to harvest urban wind power in the past have not worked effectively, due to the blocking and reduction of wind speeds by the density of urban architecture. The Cornell team is testing piezoelectric generation as a new option that appears to work on a small scale. Inspired by the mechanics of the motion of fish tails, a flexible aerofoil is attached to a pole made of piezoelectric material. The air that moves the foil then causes the pole to flex and create a small alternating electrical current.
The aerofoils tested in a wind tunnel by the scientists were about 5 inches long and proved capable of generating milliwatts of power from wind speeds of just under 5 miles per hour. If several generating processes were combined in a redesigned wind power turbine, the amount of power generated could increase quickly.
Garcia’s team is not the only one looking at applying the piezoelectric concept to wind power equipment. Cornell’s Hod Lipson and Shu-guang Li, formerly at Cornell and now with Northwestern Polytechnical University in Xi’an, China, devised a tree-like structure with flapping leaf-like generators attached to piezoelectric branches using hinges. The wind causes the generators to flap and twist vigorously, bending the branches and generating wind power. Although the leaves generate less power than Garcia’s model, they are smaller and may be less expensive to produce.
(For more on this topic, see this article in NewScientist)
Yet another Cornell duo, Kevin Pratt and Francis Charles Moon, are using concentrated solar power in honeycomb-styled arrangements of funnels to accelerate wind passing over piezoelectric strips that flap in response. Wind power is generated by the amount of air and by its speed, and this concept could be economically viable if the equipment can be produced at about one-third of the price of solar panels.
When will we know this new wind power technology is ready for consumers? While it will take several years for development of these devices to actually reach the marketplace, green energy companies and universities are conducting research and forging new partnerships. They promise to cross the boundaries of mechanical engineering, physics, nanotechnology, life sciences, materials science, architecture and design at a rapidly increasing pace, one that provides hope for the continued progress for future generations of urban wind power turbines.