Active vibration control technologies are reaching maturity in many applications, in both periodic and transient operating regimes. Historically these systems have been designed without regard for the power they consume, which is not only inefficient and costly, but limits their adoption in applications where it is impractical to provide large power supplies. Strategies for reducing power consumption include semi-active and regenerative methods. The former limits the device action to dissipative forces, through adjustable spring and/or damping rates. The latter uses the dissipative portion of the cycle to store energy in a reservoir, which can then be used in the remainder of the cycle. This paper looks at the benefits of using hydraulic devices in this context instead of the prevalent electromechanical devices. A case study of regenerative hydraulic vibration control is presented using digital hydraulics concepts, analogous to the switching power supplies and amplifiers that have revolutionised the efficiency of modern electronic equipment. The limitations and trade-offs are examined and projections are made as to the performance that could be achieved as the limitations of contemporary hydraulic components are improved upon.