Various examples of simultaneous ocean wave and current energy harvesting are described, using a hybrid ocean energy converter and a mechanical transfer system therefor. In one example, a hybrid ocean energy converter includes a two-body point absorber comprising a first body and a second body. The two-body point absorber can be configured to transfer a linear relative motion between the first body and the second body to bi-directional rotation of a first input shaft. A turbine can be configured rotate a second input shaft. The converter further includes a hybrid power takeoff including a mechanical transfer system configured to mechanically couple the first input shaft, the second input shaft, an output shaft, and an output shaft.

A runner for a hydraulic turbine configured to reduce fish mortality. The runner includes a hub and a plurality of blades extending from the hub. Each blade includes a root connected to the hub and a tip opposite the root. Each blade further includes a leading edge opposite a trailing edge, and a ratio of a thickness of the leading edge to a diameter of the runner can range from about 0.06 to about 0.35. Further, each blade has a leading edge that is curved relative to a radial axis of the runner.

A runner for a hydraulic turbine configured to reduce fish mortality. The runner includes a hub and a plurality of blades extending from the hub. Each blade includes a root connected to the hub and a tip opposite the root. Each blade further includes a leading edge opposite a trailing edge, and a ratio of a thickness of the leading edge to a diameter of the runner can range from about 0.06 to about 0.35. Further, each blade has a leading edge that is curved relative to a radial axis of the runner.

A method for driving a transmission mechanism output power in response to an anticipated fluid-pressure gradient field is provided. The method includes sensing the change of direction of pressure gradient field at a desired location from the different area of the transmission mechanism within fluid. The method further includes constructing fluid-pressure gradient field based upon isolation-fluid apparatus or low-density fluid space installed on a transmission mechanism within fluid.

A system and method for a for a wave energy converter device that is an axisymmetric point absorber which operates in a tension only condition over a large stroke that can operate in the given wave environment so as to eliminate the need for end stops in normal operation whereby the wave energy converter device has a floating hull with an interior Power Take Off (PTO) that uses an impedance control scheme for impedance matching with the wave environment in which it is deployed so as to maximize electrical power output as compared with a passively operating device of similar size.

A system and method for a for a wave energy converter device that is an axisymmetric point absorber which operates in a tension only condition over a large stroke that can operate in the given wave environment so as to eliminate the need for end stops in normal operation whereby the wave energy converter device has a floating hull with an interior Power Take Off (PTO) that uses an impedance control scheme for impedance matching with the wave environment in which it is deployed so as to maximize electrical power output as compared with a passively operating device of similar size.

A funnel-shaped underwater energy harvesting equipment includes a piezoelectric element configured to be installed at a seabed and to be moved by a fluid in order to convert vibration energy into electricity. The funnel-shaped underwater energy harvesting equipment further includes a fluid collector coupled to the piezoelectric element and configured to increase velocity of the fluid flowing toward the piezoelectric element. The harvesting equipment exhibits improved energy conversion efficiency, while simplifying the shape of the harvesting equipment.

A funnel-shaped underwater energy harvesting equipment includes a piezoelectric element configured to be installed at a seabed and to be moved by a fluid in order to convert vibration energy into electricity. The funnel-shaped underwater energy harvesting equipment further includes a fluid collector coupled to the piezoelectric element and configured to increase velocity of the fluid flowing toward the piezoelectric element. The harvesting equipment exhibits improved energy conversion efficiency, while simplifying the shape of the harvesting equipment.

A linear generator includes one or more helices, and one or more magnet members movable relative to a first helix to generate electric energy within the first helix. The first helix includes a first coil. The first helix and/or the magnet members have a density less than that of water such that the first helix and/or the magnet members have buoyant properties when the linear generator is at least partially submerged in the water.

A linear generator includes one or more helices, and one or more magnet members movable relative to a first helix to generate electric energy within the first helix. The first helix includes a first coil. The first helix and/or the magnet members have a density less than that of water such that the first helix and/or the magnet members have buoyant properties when the linear generator is at least partially submerged in the water.