Israel Technology - Energy Harvested From Automobile Traffic on Highways - Who'd "A Thunk" It?

The field of Engineering is called piezo-electricstresses, thermal strain caused by temperature
generation, and as Israel's tiny land and coastal areasdifferentials, plus controllable actuation-strain caused
do not have readily obtainable natural energy sourcesby electric voltage - all integrated into the
such as oil or gas fields, many Israeli companies arepiezo-electric effect. (Strain is a physical dimension
innovating scientific technology in pursuit of thechange in homogenous materials, from the application
"brass ring" of success. One such entrepreneurishof Force into Stress, and the Young's Modulous for
company is Innowattech, with patents for a uniquethe Material; Strain = Stress/Modulous.)
approach to harvesting commonplace urban centerThe piezo-electric generators are designed to various
activities - with the potential of generating storabledimensions from a few centimeters to large surfaces,
and re-usable energy from highways or roadways,and are imbedded below an asphalt topping layer.
railways, airport runways and even pedestrianThe parasitic energy of busy roadways, railroad-track
sidewalks.beds and airport runways, all near population centers,
The system is called IPEG for Innowattech Piezooffers the potential of conversion into electrical
Electric Generator, developed by the companyenergy that can be supplied back to customers or to
(Innowattech), with the significant potential ofa national electric grid. A normal vehicle-bearing urban
obtaining energy ordinarily wasted by commonplaceroad can be technically described as a
vehicles which abound in normal urban life centers:visco-elasto-plastic material, elasticity being the most
autos, busses, trains, etc. The engineering principleimportant parameter and physical characteristic. As a
involves weight changes, motions, vibrations andvehicle travels along the road, vertical displacement
temperature variations, the concept usingoccurs under the tires which transmit the vehicle
piezo-electric generators specifically designed forweight to the road - the reaction being thermal
application to highways, rail track beds, runways, etc.energy. With piezo-electric generators imbedded in
The general concept is the capturing or harvesting,the road material, part of the energy expended in
storing and then re-using parasitic mechanicalroad deformation can be transformed into electrical
energies; the piezo-electric effect of convertingenergy (piezo-electric effect) and recovered, instead
mechanical "strain" energy into electrical current orof just being wasted as heat. The principle and
voltage. The constitutive relations for piezo-electrictechnology are sound, developments in play will
materials are based on the total strain in thedetermine operational efficiencies and the limitations
actuator, the sum of mechanical strain induced byof practical applications.