The system includes a support structure with upstream and downstream pulleys rotatably supported thereby and with cables following circuits around each of the upstream and downstream pulleys. Prime movers, such as in the form of sail members, are attached to the cable. These prime movers have surfaces which are more perpendicular to the flowing water when on a downstream leg of the cable circuit than when on an upstream leg thereof. The prime movers are configured to rotate as they pass about the downstream pulley and upstream pulley to optimize their orientation to minimize drag when following the upstream leg of the circuit and to maximize surface area against which the flowing water acts when following the downstream leg of the cable circuit. Power is outputted from the system through action of the cable upon a power output such as an electric generator coupled to one of the pulleys.

The system includes a support structure with upstream and downstream pulleys rotatably supported thereby and with cables following circuits around each of the upstream and downstream pulleys. Prime movers, such as in the form of sail members, are attached to the cable. These prime movers have surfaces which are more perpendicular to the flowing water when on a downstream leg of the cable circuit than when on an upstream leg thereof. The prime movers are configured to rotate as they pass about the downstream pulley and upstream pulley to optimize their orientation to minimize drag when following the upstream leg of the circuit and to maximize surface area against which the flowing water acts when following the downstream leg of the cable circuit. Power is outputted from the system through action of the cable upon a power output such as an electric generator coupled to one of the pulleys.

The present disclosure provides a bicycle-like pressure-differential engine apparatus that takes advantage of the pressure gradient that occurs with changes in height due to gravitational pull in a fluid environment to generate energy. A closed chain of compressible elements wrapped around and coupled to a pair of toothed vertical wheels having aligned axes of rotation is positioned in the same vertical plane. A rigid frame structure holds the wheels at a set distance from one another and a coupling assembly links the rotational motion of the two vertical wheels, the coupling assembly comprising a set of ratioed gears. The compressible elements at the top experience a different pressure to those at the bottom, causing expansion and contraction of the chain at different points along its length, except for those elements trapped between the teeth of the wheels, which in turn generates thrust and rotates the wheels.