|Fig. 1: Energy flow: standard shock absorber vs Genshock.|
The declining supply of world oil is urging entrepreneurs to create energy efficient consumer products. In particular, the "go green" movement in the automobile industry has seen to the advent of hybrid cars such as the Toyota Prius. Even better are products which make use of energy that is otherwise wasted.
Levant Power is able to achieve this, with their Genshock Technology (GST). They have designed a state of the art shock absorber which harnesses energy stored in suspension springs. In conventional shock absorbers, this energy is lost as heat.
As a vehicle travels over a rough surface, it undergoes vertical acceleration. This can be unpleasant for passengers and can degrade the vehicle over time. In modern vehicles, a set of springs and shock absorbers known as a suspension system serves to minimize these unwanted effects. The spring absorbs kinetic energy involved in vertical motion of the tire while the shock absorber acts as a damper on the spring. Typical shock absorbers convert spring energy into thermal energy, releasing wasted heat into the environment.
Most modern vehicles make use of hydraulic shock absorbers. In a hydraulic shock absorber, a piston slides back and forth in a cylinder filled with a viscous fluid, forcing it through a series of flow valves and tiny orifices. As the fluid passes through the small orifices it experiences viscous friction, causing the fluid to heat.
Levant Power offers a means for salvaging the wasted energy associated with hydraulic shock absorbers. Instead of using tiny orifices to create viscous friction and damp the springs, Genshocks route fluid through hydraulic motors. The fluid experiences resistance as it acts on the motor, thus damping the springs. Instead of creating wasted thermal energy, Genshocks create rotational kinetic energy in a motor which powers an electric generator. The exact design is not available to the public, but probably consists of a fluid circuit akin to the wave rectifier in electronics (Fig. 1). Naturally, fluid current alternates as the vehicle moves up and down. In a rectified fluid circuit, the fluid will flow in one direction, ensuring that the electric generator is constantly being powered. The generated electricity is used to charge the vehicle battery. As a bonus, Genshocks can also power a feedback loop to dynamically control damping based on terrain, allowing for a smoother ride.
According to Levant Power, GST might increase vehicle fuel economy (VFE) by 2-5%, a number that depends on vehicle size and terrain traveled over.  According to the Federal Highway Administration (FHWA), the average US passenger car VFE in 2006 was 22.3 mpg (9.5 km/L).  Assuming GST improves passenger car VFE by 3.5% on average, and that all US cars in 2006 had GST on-board, this number would be 23.1 mpg (9.83 km/L). According to FHWA, US passenger cars traveled a total of 1.68 × 1012 mi (2.71 × 1012 km) in 2006, consuming 
(285. × 109 L) of gasoline. The energy density of gasoline is ~34.2 × 106 J/L. Hence, the total energy consumed in the US by passenger vehicles in 2006 was
Had all passenger vehicles used GST in 2006, this number would have been (assuming a VFE of 23.1 mpg)
an energy savings of 3.4 × 1017 J.
© Derek Mendez. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 Lawrence Ulrich, "Invention Awards: Power From Shock Absorbers," Popular Science, May 2009.
 United States Federal Highway Administration, "Annual Vehicle Distance Traveled in kilometers and Related Data - 2006 (Table VM-1M)," Highway Statistics 2006 (Office of Highway Policy Information, Washington, D.C., 2006)