Disclosed is an apparatus that adapts the rate of its computational work to match the availability of energy harvested from a stochastic energy source; and, with respect to some types of energy harvesting, regulates the rate of energy capture, the rate of energy conversion, and the rate of consumption of stored potential energy, through its alteration, regulation, and/or adjustment, of that same computational work load.

A renewable energy and waste heat harvesting system is disclosed. The system includes an accumulator unit having a high pressure accumulator and a low pressure accumulator. At least one piston is mounted for reciprocation in the high pressure accumulator. The accumulator unit is configured to receive, store, and transfer energy from the hydraulic fluid to the energy storage media. The system collects energy from a renewable energy source and transfers the collected energy using the pressurized hydraulic fluid. The system further includes one or more rotational directional control valves, in which at least one rotational directional control valve is positioned on each side of the accumulator unit. Each rotational directional control valve includes multiple ports. The system also includes one or more variable displacement hydraulic rotational units. At least one variable displacement hydraulic rotational unit is positioned adjacent each of the rotational directional control valves.

A fail-safe actuation system comprising an actuator having first and second chambers, a working circuit with a motor/pump device configured to actuate the actuator in an operative state, and a safety circuit configured to move the actuator into the safety position in a failure state, the safety circuit having a tank that holds pressurized fluid and that, in the failure state, is automatically connected to the first chamber via a switching valve, and having a drain valve that, in the failure state, is moved into a through-flow position in order to drain fluid out of the second chamber, the safety circuit configured such that, in the operative state, an inflow into the actuator—in a manner that is decoupled from the tank—is established by the working circuit, and, in the failure state, an inflow from the tank into the first chamber—in a manner that is completely decoupled from the working circuit—is created by the safety circuit, whereby a short-circuit fluid connection is provided between the first and second chambers that, in the failure state, is through-connected in order to generate a short-circuit flow between the first and second chambers.

According to an example aspect of the present invention, there is provided a system for harnessing energy from moving ice, the system comprising a first part configured to move into a first direction under pressure caused by moving ice at least until an ice compression strength is reached and to subsequently move into a second direction, and a second part configured to transform kinetic energy of a cyclic motion of the first part into electric energy.

Wave energy conversion systems are provided utilizing a mass of water entrained in a collapsible water mass enclosure that is suspended beneath a float (e.g., a vehicle, buoy, platform, etc.) to provide an inertial force in opposition to the rising heave-induced acceleration of the float. The water mass enclosure is communication with a generator, such as by tethering one end of a tethering means to the generator and the other to the enclosure. The enclosure may be placed in communication with an intermediary hydraulic system, which is also in communication with the generator. In certain embodiments, the system will include a reel system for deploying and retrieving the water masse enclosure.

A wave energy converter (WEC) buoy includes at least one pitch-driven WEC (“PDWEC”) device. Each PDWEC device includes two reaction masses which are placed at diametrically opposite ends of a container designed to float along the surface of a body of water and to move in response to the pitching motion of the waves. The reaction masses are interconnected so that when one reaction mass moves up, the diametrically opposed reaction mass moves down, and vice-versa. The movement of the reaction masses drives power take off (PTO) devices to produce useful energy. The reaction masses may be interconnected by any suitable linking system. One or more PDWEC device may be combined with a heave responsive device to produce a WEC buoy which can produce a power output in response to pitch or heave motion.

A braking system for a turbine of a wind powered includes a hydraulic machine connected to a drive shaft of the turbine. A pressure regulating valve in the supply line of the hydraulic machine determines the pressure delivered to the supply line by the hydraulic machine. A control that is responsive to the speed of rotation of the drive shaft modulates the pressure regulating valve so as to increase pressure in the supply line as the rotational speed exceeds a predetermined speed to apply a braking force to the drive shaft.

An assembly for converting linear and rotational motions of a floating vessel into electrical energy. The assembly provides a floating vessel, such as a boat, and an operationally connected power generation unit that harnesses the natural buoyant movements of the vessel to generate electrical energy in the power generation unit for use by the vessel or other electrical consumption system. As the vessel moves in linear and rotational movements, the power generation unit reciprocally pivots. This pivoting motion urges a push rod in and out of the power generation unit. A piston extends from the push rod. A reservoir feeds hydraulic fluids through a closed loop system. The piston urges the hydraulic fluid into a hydraulic motor that creates a mechanical action. A generator converts the mechanical action to electrical energy. A platform pivots between a table position and a step position to provide greater functionality of the vessel.

A power take-off arrangement for a wave energy converter is described. The arrangement has a gearbox having a first shaft (20) connected to the wave energy converter (1) which is adapted to receive, in use, rotational motion from the wave energy converter. The gearbox has a second shaft connecting the annulus gear (31) to the generator shaft (36). A third shaft (38) is connected to one or more means (39) of applying torque to it. Torque applied by the one or more means (39) may be varied in operation so as to alter the relative rotational velocities and accelerations of the second and third shafts in response to any given rotational velocity or acceleration of the first shaft.

The present invention relates to a method of operating a fluid-working machine wherein the volume of working fluid displaced each cycle is selectable and wherein the volume of working fluid displaced by a first working chamber takes into account the suitability of the working chamber to displace fluid. The invention extends in further aspects to power absorbing structures such as renewable energy devices comprising such fluid working machines. The invention allows the operation of fluid working machines and power absorbing structures which are more long lived.