An Israeli energy start-up wants to turn irritating rush-hour traffic into a source of electricity.
Innowattech, an energy company affiliated with Israel's Technion Institute of Technology, said special generators placed under roads, railways and runways can harvest enough energy from passing vehicles to mass-produce electricity.
The generators contain material that produces electricity when mechanical force is applied, like the pressure from a passing car's tires.
The process, known as piezoelectricity, has been used for years on a smaller scale, including in barbecue lighters and a dance club where the pounding feet of dancers light the floor.
Uri Amit, chairman of Innowattech, said the company's technology will be the largest application of piezoelectrics to date, with a single 1-km (half-mile)-lane of highway providing up to 100 kw of electricity, enough to power about 40 houses.
The technology has its limitations since it can collect a steady flow of electricity only from busy roads and rails. But Amit said that in any case, peak-hour morning and evening demand for power coincided with heavy traffic at the start and end of the business day.
"We can produce electricity anywhere there is a busy road using energy that normally goes to waste," Amit said.
He said the first pilot program would begin in the coming months on a 30 meter (90 foot) strip of highway outside Tel Aviv and that similar projects could start internationally in 2010.
Efstathios Meletis, chairman of the Materials Science and Engineering Department at the University of Texas at Arlington, said the Innowattech technology was a "sound idea that theoretically could be done".
But problems, he said, could arise in the implementation and the coordination needed to bury the generators over vast amounts of highways and train tracks.
One of the hurdles was finding a way to package the generators so they are effective when buried in the road. The company's chief scientist, Eugeny Harash, developed a casing that acts like asphalt. The generators are then put in the road during scheduled maintenance in 30 cm (11 inch) squares.
"The asphalt is elastic and the pressure of each tire that passes is picked up by the generator, which is buried about 3 cm (1 inch) below the road's surface," Harash said. "The drivers won't even feel a difference."
The piezoelectric material lasts for at least 30 years, which is longer than most roads, Harash said.
The generators can also be placed in the sleepers, or cross ties, of rail tracks to harvest the energy of trains, he said.
The energy is transferred to storage systems that are set up along the road at about every 500 meters (0.3 miles). The power can then be fed into a main grid, or even used to charge batteries as part of a future electric car infrastructure.
Innowattech chairman Amit said the current cost for fitting a kilometer (half-mile) of one lane of highway is about $650,000, with a cost of $6,500 per kilowatt. He said when mass production begins, the price could drop by two thirds, making the system even cheaper than solar energy systems.
The company said the target cost of generation is 3-10 cents per kilowatt/hour, depending on the amount of traffic. Wind generated energy has comparable costs.