A method is provided for operating an energy storage device that has a horizontal flywheel (1). The flywheel (1) has a mass ring made of concrete (3) and is at least partially embedded in the soil (4). The method includes operating a motor with energy from a first energy source to drive the flywheel (8) at a specified rotational speed and to store energy in the flywheel (1). The method then includes introducing to the motor (8) energy from a renewable energy source in a sufficient amount so that the energy from the renewable energy source and the energy stored in the flywheel (1) maintain rotation of the flywheel at the specified rotational speed.

An electric generator is provided including a stator assembly, a rotor assembly being rotatably supported at the stator assembly for rotating around a rotational axis, an annular device being fixed to the rotor assembly and including an engagement structure, and a first turning device being mounted to the stator assembly, the first turning device including an actuator and an engagement element being drivable by the actuator. The first turning device is configured for adopting two operational states, an active operational state and a passive operational state. In the active operational state there is an engagement between the engagement element and the engagement structure and in the passive operational state the engagement element and the engagement structure are mechanically decoupled from each other.

An apparatus including a pneumatic system; an energy harvesting unit configured to generate electrical energy from a compressed gas in the pneumatic system; a battery connected to the energy harvesting unit; a sensor disposed to detect a first parameter regarding operation of the energy harvesting unit; and a controller connected to the sensor and the energy harvesting unit. The sensor and the controller are powered by the energy harvesting unit. The controller is configured to control the energy harvesting unit and to process measurements for the first parameter detected by the sensor. The controller is further programmed with a learning system configured to diagnose an operational condition of the energy harvesting unit based on the measurements for the first parameter, and to issue a command to the controller based on the operational condition.

A thermal energy harvesting device includes a rotatable shaft and a shape memory alloy element secured to rotatable shaft. The shape memory alloy element is adapted to undergo a shape memory effect upon reaching a transition temperature, which causes rotation of the rotatable shaft. The rotatable shaft may be operatively connected to a generator or tachometer to convert the rotation of the shaft into electrical energy, which may then be stored in a rechargeable battery. In certain embodiments a gear box may be provided to increase the speed of rotation, and thereby increase the amount of electrical energy created.

A swivel (100) for a mooring line comprises a first element (110) with a first line coupler (111) and a second element (112) with a second line coupler (113). The first element (110) and the second element (112) are rotatable relative to each other. An electric power generator (120) converts a relative rotation between the first element (110) and the second element (112) into electric power. In use, the line couplers (111, 113) are attached to separate segments of the mooring line. A pull F applied to or relieved from the mooring line causes the relative rotation. The swivel preferably contains a battery and a control unit, and may supply power to one or mode sensors, transmitters and/or transducers (130) built into or external to the swivel (100). A system for monitoring a mooring arrangement is also disclosed.

A power supply system installed on a rotating object includes: a power generation device, and a power management device for converting the electric power output by the power generation device to adapt to load requirements, in which the power generation device includes a rotor installed on and fixed to the rotating object, the rotor including at least one induction coil, and a stator which is rotatable relative to the rotor, the stator including at least two magnetic poles; the stator includes a stator case and a counterweight block, and the stator case surrounds the rotor from the circumferential direction of the rotor, and is closed in the circumferential direction; and the counterweight block is fixedly arranged at one side of the stator case, and the angle of the counterweight block in the circumferential direction is in the range of less than or equal to 180 degrees.

Embodiments of a hydroelectric system for a low head dam can include a module including a protective housing, a turbine housing retained within the protective housing, the turbine housing including an upper inlet portion at a first end, a substantially tubular portion, and a lower outlet portion at a second end, the upper inlet portion being positioned above the lower outlet portion, a turbine retained at least partially within the turbine housing, the turbine including a plurality of blades coupled with a central shaft, and a fluid pump, the fluid pump being coupled with the central shaft, where the fluid pump is configured to pump a high pressure fluid, a fluid circuit, the fluid circuit including piping, where the high pressure fluid is retained within the piping, and a shoreline generator, the shoreline generator being coupled with the fluid circuit, where the offsite generator is driven by the high pressure fluid that is pumped by the fluid pump in response to the rotation of the turbine.

The invention relates to an autonomous retarder system for a vehicle including a retarder (10) having a central rotor (11) and two stators (12), one on each side of the rotor (11). The rotor (11) is rigidly coupled to an axle (1). A generator (20, 30, 50) is also included, coupled to the retarder (10), for supplying same with electrical energy. In addition, the generator (20, 30, 50) comprises a stator (22) and a rotor (21, 31, 51) coupled to the retarder.

An electric machine including a stator having a fully non-magnetic core and stator windings formed of a non-superconducting transposed conductor to reduce eddy current losses. It further includes a rotor having a fully non-magnetic core and superconducting windings or superconducting magnets which produce a magnetic field for interaction with the stator windings. A cryogenic cooling system is arranged to cool the stator windings to reduce conduction losses in the stator windings.

The invention relates to a magnetic generator (1) comprising at least one rotary drive means (2) having an axle associated with an actuator system, the actuator system comprising at least one induction rotor (5) associated with the axle of the rotary drive means (2), the induction rotor (5) comprising magnetic inductor structures (6), the induction rotor (5) being associated with at least one induced rotor (7) comprising induced magnetic structures (8) configured so as to cooperate with the inductive magnetic structures (6) so that the inductive magnetic structures (6) driven by the induction rotor (5) cause the induced structures (7) and the induced rotor (6) to rotate, said induced rotor (6) being associated with an electric power generation means (9).