In various embodiments, an apparatus for producing electricity includes a plurality of hydraulic-to-electric converters with each hydraulic-to-electric converters including a hydraulic motor coupled to a common high-pressure hydraulic line and a common low-pressure hydraulic line, a controllable hydraulic switch hydraulically coupled to each respective hydraulic motor, each controllable hydraulic switch being capable of controllably placing the respective hydraulic motor on-line by allowing flow of hydraulic fluid from the common high-pressure hydraulic line through its respective hydraulic motor or off-line by preventing flow of hydraulic fluid from the common high-pressure hydraulic line through its respective hydraulic motor, and an electric generator mechanically coupled to each respective hydraulic motor and configured to generate electricity when hydraulic fluid flows through the respective hydraulic motor. The apparatus further includes a control system coupled to each controllable hydraulic switch configured to place individual hydraulic motors on-line or off-line as a function of available energy provided by the high-pressure line.