‘Electric’ highways may be close
April 27, 2011
• Venerable physics principal may be used to generate power
• Highways could become latest source of alternative power
California’s motorists could become small generators of electricity as they drive about the state some day.
A bill to test the principal of "piezoelectric generation” has been approved 6-1 by the state Assembly Natural Resources Committee. It still has other committee hurdles to clear to make it to the floor for a vote, however.
The bill by Assemblyman Mike Gatto, D-Los Angeles, would require the state Energy Commission to conduct research on the feasibility of generating electricity using piezoelectric transducers under major roadways as a renewable resource.
Caltrans and the commission would build the transducers into roadway beds in the pilot program and report results by 2013.
Mr. Gatto says piezoelectric generation, can produce as much as 44 megawatts of electricity per year from one single-lane, stretch of roadway no more than six-tenths of a mile in length. That’s enough electricity to power 30,800 homes for a year.
The science works as follows, explains Mr. Gatto:
When a car or truck passes over pavement, the pavement vibrates ever so slightly. (You can feel these vibrations if you have ever stood on a road as a truck speeds by.) By placing “relatively inexpensive” piezoelectric sensors underneath a road, the vibrations produced by vehicles can be converted into electricity, which can be used to power roadside lights, call boxes, and neighboring communities.
He says identical technology has already been placed underneath highways in Israel, and Italy has signed a contract to place the technology under a stretch of the Venice-to-Trieste Autostrada.
The technology can be placed under asphalt during regularly scheduled repaving, and does not affect the vehicles traveling on the road, in terms of "road feel", fuel efficiency, or emissions, he says.
"A major source of renewable energy is right beneath our feet -- or, more accurately, our tires. California is the car capitol of the world. It only makes sense to convert to electricity the energy lost as cars travel over our roads," says Mr. Gatto.