Cambridge, Massachusetts – A team of undergraduate students from the Massachusetts Institute of Technology (MIT) has invented a shock absorber that harnesses energy from small bumps in the road, generating electricity while smoothing the ride more effectively than a conventional shock.
The students have already drawn interest from the U.S. military and several truck manufacturers for the design. AM General, which builds the Humvee for the army and is working on the next generation of the vehicle, has lent the researchers a vehicle for testing purposes.
Senior Shakeel Avadhany and his teammates say they can produce up to a 10 per cent improvement in overall vehicle fuel efficiency by using the regenerative shock absorbers. The project began when the students tried to determine where energy is wasted in a vehicle, and rented a variety of models, outfitting the suspensions with sensors to determine the energy potential. The tests showed a significant amount of energy was being wasted in conventional suspension systems, especially in heavy vehicles.
The prototype shock absorbers use a hydraulic system that forces fluid through a turbine attached to a generator. The system is controlled by an active electronic system that optimizes damping, providing a smoother ride than conventional shocks while generating electricity to recharge the batteries or operate electrical equipment.
In testing, the students have found that in a six-shock heavy truck, each shock absorber could generate up to an average of one kilowatt on a standard road, enough to completely displace the large alternator load in heavy trucks and military vehicles, and in some cases, even run accessory devices such as hybrid trailer refrigeration units. If the electronics fail for any reason, the system simply acts like a regular shock absorber.
The students have filed a patent and formed a company, Levant Power Corporation, to develop and commercialize the product, and plan to have a final, fine-tuned version of the device ready this summer. The group has estimated that a company such as Wal-Mart could save US$13 million per year in fuel costs by converting its fleet of trucks to the system.