Researchers designed an Energy-Harvesting Shock Absorber that converts vibration, bumps, and motion experienced by the suspension of a vehicle or train into electric power. This Regenerative Shock Absorber for cars can harvest over 100 watts from the vehicle vibrations under normal driving conditions.The electricity-harvesting shock absorber is made to be retrofittable to most of the current vehicles and can replace the traditional shock absorber without modification of the vehicle suspension structure.

Energy Harvesting Shock Absorber Generates Power from Vibration & Vehicle SuspensionProfessor Lei Zuo and his students at Stony Brook University have designed retrofittable regenerative shock absorbers with high energy density that recovers a vehicle’s vibration energy. This technology has the ability to continuously recover a vehicle’s vibration energy that is otherwise dissipated due to road irregularities, vehicle acceleration, and braking, and further use the energy for better suspension control.

They estimated that for a middle-size vehicle, 100W, 400W, and 1600W of average power is available for harvesting from the regenerative shock absorbers while driving on Class B (good), C (average), and D (poor) highways at 60 mph, which is comparable with the car alternators (500-600W). And the energy potential for trucks, rail cars, and off-road vehicles is on the order of 1kW-10kW. This represents a potential of 1-4% fuel efficiency increase in conventional cars and up to 8% for hybrid vehicle.

The team at Stony Brook University has designed and patented both linear and rotational electromagnetic energy harvester to replace the traditional shock absorbers and make the vehicles suspension dual functional: mitigating vibration and electricity-generating. A unique configuration using both radial and axial magnets is used in the linear harvester design, and a compact motion magnification mechanism is employed in the rotational harvester.