A power transmission system for a wind turbine includes a main shaft configured to be driven by the rotor about a main axis, a support structure including at least one bearing supporting the main shaft for rotation about the main axis, and a gearbox having a gearbox housing rigidly coupled to the support structure and a gearbox input member coupled to the main shaft. The gearbox housing supports the gearbox input member for rotation about the main axis, and the gearbox input member is coupled to the main shaft with a translational degree of freedom along the main axis and rotational degrees of freedom about axes perpendicular to the main axis. The main shaft is coupled to the gearbox input member by a flexible coupling positioned at least partially within the main shaft. The flexible coupling may be positioned entirely within the main shaft.

A Savonius wind turbine includes a rotor assembly that rotates about a longitudinal axis. The rotor assembly includes at least two curved turbine blades extending parallel to the longitudinal axis and at least two support discs connected to the at least two curved turbine blades. At least one of the at least two support discs has at least one relief vent defined therein for allowing air to pass through the at least one support disc. The wind turbine may be provided with two rotor assemblies having their curved turbine blades arranged so that the rotor assemblies are driven to rotate in opposing rotational directions.

A water mill, power generator, for use underwater, has a flexible support shaft which permits the water current to orient the turbine axis substantially parallel to the direction of flow so that the force of the water on the blades is optimized for a given turbine, without the need for slip ring style connections between the generator at the turbine and the 5 anchored base. Optionally, the design features fins or cowlings on the flexible support shaft to further improve reorientation of the turbine with the water current or flow acting as the source of power; and/or output power links or power conditioning systems at the anchored base. The generators may be selected to meet low rotation operating conditions, and the entire system may be designed for particular ocean bottom and/or current parameters applicable to the 10 deployment.

A turbine apparatus (10) for deployment in a waterway, comprises a rotor support system (12), a rotor mechanism (14) and a power take-off device (16). The rotor support system (12) is operable to support and align the rotor mechanism (14) with a direction of flow of flowing water in the waterway. Deployment of the turbine apparatus (10) in flowing water generates power. The rotor support system (12) includes an elongated shaft (13), which includes a buoyancy adjusting component (17); a flexible coupling (15) at a first end; and the rotor mechanism (14) being attachable to a second free end of the elongated shaft (13). The flexible coupling (15) facilitates connection of the first end of the elongated shaft to a support structure and facilitates a substantially freely yawing connection of the axial flow turbine apparatus to a support structure located in the waterway in which the turbine apparatus is deployed. The flexible coupling (15) also controls pitching motion of the turbine apparatus (10) relative to the support structure; and in use, permits a predetermined range of yawing motion of the turbine apparatus relative to the support structure; and responds to changes in flow of the flowing water, to maintain the turbine apparatus (10) with a compliant attitude, thereby maintaining alignment of the axis of the elongated shaft and the rotor mechanism with the direction of flow. The buoyancy adjusting component (17) being operable to maintain the deployed turbine apparatus with substantially neutral buoyancy relative to the waterway in which the turbine apparatus is deployed.

Disclosed herein are flexible wave energy converters that actuate electrical generators with dynamic strain (e.g., flexing, stretching, twisting, distension) to convert wave energy to electrical energy. The flexible wave energy converter utilizes flexible electric generators embedded throughout the wave-energy converter's flexible body.

Disclosed herein are flexible wave energy converters that actuate electrical generators with dynamic strain (e.g., flexing, stretching, twisting, distension) to convert wave energy to electrical energy. The flexible wave energy converter utilizes flexible electric generators embedded throughout the wave-energy converter's flexible body.

Disclosed herein are flexible wave energy converters that actuate electrical generators with dynamic strain (e.g., flexing, stretching, twisting, distension) to convert wave energy to electrical energy. The flexible wave energy converter utilizes flexible electric generators embedded throughout the wave-energy converter's flexible body.

Disclosed herein are flexible wave energy converters that actuate electrical generators with dynamic strain (e.g., flexing, stretching, twisting, distension) to convert wave energy to electrical energy. The flexible wave energy converter utilizes flexible electric generators embedded throughout the wave-energy converter's flexible body.

A Savonius wind turbine includes a rotor assembly that rotates about a longitudinal axis. The rotor assembly includes at least two curved turbine blades extending parallel to the longitudinal axis and at least two support discs connected to the at least two curved turbine blades. At least one of the at least two support discs has at least one relief vent defined therein for allowing air to pass through the at least one support disc. The wind turbine may be provided with two rotor assemblies having their curved turbine blades arranged so that the rotor assemblies are driven to rotate in opposing rotational directions.

The disclosure relates to an apparatus for generating electric power from a fluid current. The apparatus comprises a generator unit, a flexible shaft that is, at a first end, rotatably attached to the generator unit, and at a second end attached to a turbine. The turbine comprises a plurality of blades and a rim attached to the plurality of blades.