We already harvest the power of the sun and the wind. Soon we may also harvest the power of potholes.
A type of shock absorber under development by the Levant Power Corporation converts the bumps and jolts of vehicles on rough roads into usable electricity. Usually, shock absorbers dissipate the energy of bouncing vehicles as heat. But the new shocks can use the kinetic energy of bounces to generate watts, putting the electricity to use running the vehicle's windshield wipers, fans or dashboard lights, for example.
The devices, called GenShocks, can be installed in both ordinary and hybrid vehicles, lowering fuel consumption by 1-6 percent, depending on the vehicle and road conditions, says Shakeel Avadhany, chief executive of the company, which is based in Cambridge, Mass.
The new shocks look like ordinary shock absorbers with an electrical power cord at one end. They plug into a power box that regulates the electricity they produce, putting it out at a voltage required by the truck, car or bus.
GenShocks will cost slightly more than conventional shock absorbers, Avadhany says, "but you will get those dollars back through improved fuel economy." He projects that the products will be on the market in the second quarter of 2011.
GenShocks are among many innovations in a field known as energy "harvesting" -- collecting energy that would otherwise be wasted.
- In May, the National Science Foundation awarded a small-business-innovation research grant of $150,000 to Levant to test its shock absorbers with hybrid trucks. Juan Figueroa, a program director at the foundation, says the economic impact of the new shock absorbers could be immediate if owners of truck fleets installed them.
- Another market that the company is pursuing is military vehicles, says Lt. Gen. John Caldwell, who retired from the Army and now consults for the Spectrum Group in Alexandria, Va. He has assisted Levant in its discussions with the Army and says that some of the energy created by the new shocks could be used to power radios and communications and weapons systems on combat vehicles.
Much useful energy could be harvested on roadways, says Ted Bergman, a program director at the National Science Foundation. Bergman is administering a new program, undertaken jointly with the Department of Energy, to research ways to harvest waste heat in vehicles and thus reduce reliance on foreign sources of oil.
"Seventy-five percent of the energy in vehicles with combustion engines is lost to waste heat," he says. "Instead of losing that energy, we want to convert some of it into kilowatts of electric power."
In hybrid vehicles, Avadhany says, his new shock absorbers could complement regenerative brakes, which can harvest energy otherwise lost in stopping and return it to the battery.
Other researchers are developing different types of energy-producing shock absorbers. Lei Zuo, an assistant professor of mechanical engineering at Stony Brook University in Stony Brook, N.Y., has built two prototypes that generate electricity with electromagnets, producing potential fuel-efficiency gains of 2-10 percent, he says.
Several companies, Zuo says, have contacted him about licensing the technology or developing it collaboratively. "I was surprised," he says, "at how much interest there is."