Systems and methods for operating a hydraulically actuated device/system are described herein. For example, systems and methods for the compression and/or expansion of gas can include at least one pressure vessel defining an interior region for retaining at least one of a volume of liquid or a volume of gas and an actuator coupled to and in fluid communication with the pressure vessel. The actuator can have a first mode of operation in which a volume of liquid disposed within the pressure vessel is moved to compress and move gas out of the pressure vessel. The actuator can have a second mode of operation in which a volume of liquid disposed within the pressure vessel is moved by an expanding gas entering the pressure vessel. The system can further include a heat transfer device configured to transfer heat to or from the at least one of a volume of liquid or a volume of gas retained by the pressure vessel.