Electric vehicles have embraced regenerative technology to such an extent that many manufacturers now offer one-pedal driving in nearly every EV on the market. In this mode, pressing down on the pedal makes the vehicle accelerate, while lifting off causes the motor to act as a generator, converting kinetic energy back into electricity to temporarily recharge the battery.

Motor generators are capable of both delivering and receiving torque, meaning they can capture energy if inertia is present. This concept raises an interesting question: Can we harness energy from sources like wind, waves, or hydro dams and redirect it to unconventional systems, such as shock absorbers? Shock absorbers, in essence, are linear brakes, so rather than allowing them to dissipate energy as heat through oil oscillation, could we not redirect that energy back into the system?

The concept of regenerative suspension isn't new. Manufacturers have been experimenting with electrohydraulic suspension systems since the early 2000s. They realized that by using pumping systems within dampers, we could transform those dampers into energy-capturing devices. On a smooth road, there’s already significant suspension oscillation occurring, and on bumpy roads, that movement becomes a goldmine of untapped energy waiting to be harnessed.

As recently as 2015, Audi worked on their eROT system, an electromechanical suspension that could convert kinetic energy into electricity to charge the battery, reducing the load on the alternator. However, they found that only about 100-150 watts could be recuperated on average—not a huge amount, but it’s still a potential area for further development.

But what if the energy dissipated from suspension oscillation in heavy vehicles, particularly those driven off-road, could be captured? Many modern machines, such as farm tractors designed for occasional road use, already use hydropneumatic suspension systems with accumulators. By modifying the circuit, perhaps with a series of check valves and an additional accumulator, the high-pressure spikes inside oil-filled dampers could be harnessed.

Hydraulic regeneration is already in use, with several manufacturers offering solutions for vehicles that require frequent stop-and-start operations, like garbage trucks and loaders. These vehicles use a pump/motor system that switches between charging an accumulator during braking and driving the wheels, offering a significant torque boost to help get these heavy vehicles moving.

This type of system could also benefit any large vehicle through its suspension. Hydraulic accumulators are capable of handling massive pressure and flow over short periods, making them ideal for providing starting torque and reducing fuel consumption during full-throttle driving. There's no reason such systems couldn't be integrated into electric or hybrid mobile hydraulic machinery, as heavy equipment will likely still rely on oil-based suspension dampers for the foreseeable future.