Harnessing The Wind's Vibrations For Electricity
Photos: Cornell University Vibro-Research Group (From left: Jamie Pelletier, Albert Dodson, Rona Banai, Zach Gould, Marco Zhang, mechanical engineering professor Frank Moon and Jared Valentin.)
As a renewable energy resource, wind has lots going for it - but one major downside is the cost to set up the wind turbines themselves, not to mention the problematic visual impact and the noise pollution it generates (often likened to a small jet engine, especially for those living close by). However, undergraduate students from Cornell University's Vibro-Wind Research Group are working on a space-saving prototype that will harness wind power more cheaply and efficiently - by transforming the wind's vibrations into electricity.
Working with a $100,000 grant from the Cornell Center for a Sustainable Future, a group of engineering and architecture students designed a 'vibro-wind' panel fitted with foam oscillators which convert and store the mechanical energy of wind vibrations into electric energy. It's done with the help of a piezoelectric transducer, which is a ceramic of polymer device that releases electrons when stress is applied.
A quick explanation of piezoelectricity from Wikipedia:
Piezoelectricity is the ability of some materials (notably crystals, certain ceramics, and biological matter such as bone, DNA and various proteins) to generate an electric field or electric potential in response to applied mechanical stress. The effect is closely related to a change of polarization density within the material's volume. If the material is not short-circuited, the applied stress induces a voltage across the material. However, if the circuit is closed the energy will be quickly released. So in order to run an electric load (such as a light bulb) on a piezoelectric device, the applied mechanical stress must oscillate back and forth. For example, if you had such a device in your shoes you could charge your cell phone while walking but not while standing.
Compared to your regular wind turbine, the piezoelectric vibro-wind panel requires a lot less space and money to install.
Close-up of the vibro-wind panel, with student Zach Gould.
"The thing with turbines and windmills is that you need wide open space, and you need it to be away from the city, because people don't like the way they look," explains chemical engineering major Rona Banai, chief student engineer of the Vibro-Wind group. Alternatively, the group is now also looking into the possibility of using an electromagnetic coil instead of a transducer.
Vibration energy harvesting has been around for a while, with recent related concepts that include the harvesting of crowd energy, along with inventions that could transform the mechanical energy from human motion to power gadgets. With ideas like this vibro-wind panel, it would be wonderful to someday see wind energy harvesting integrated into many aspects of everyday life (à la Nausicaa of the Valley of the Wind), with vibro-wind panels on your roof, much like solar panels, or portable apparatuses that could power your electronics or vehicle as you move.
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