Methods and systems are provided for a power-generating fluid flow arrangement. In one example, the fluid flow arrangement may include a primary conduit flowing a pressurized fluid and a bypass conduit coupled to the primary conduit. The bypass conduit may divert a portion of the pressurized fluid flow from the primary conduit to drive rotation of a turbine. A dual valve may be arranged in the bypass conduit to control both flow and pressure in the fluid flow arrangement.

A first aspect of the invention provides a method of monitoring the condition of a yaw system of a wind turbine, the wind turbine comprising a rotor, the yaw system arranged to control a yaw rotation of the rotor, the method comprising: providing design data 5 representing an expected relationship between yaw moment and yaw rotation speed; measuring a pair of parameters, the pair of parameters comprising a yaw moment parameter indicative of a yaw moment applied to the yaw system, and a yaw rotation speed parameter indicative of a yaw rotation speed caused by the yaw moment; using the design data to evaluate whether the pair of parameters deviates from the expected 10 relationship; and determining a condition of the yaw system on the basis of the evaluation.

A machine for driving an electric generator moves a power module through a DOWN and UP duty cycle along a closed-loop, vertically oriented pathway. In the DOWN portion of the duty cycle, the module falls through air under the influence of gravity and generates kinetic energy for work to drive the electric generator. Upon disengagement of the power module from the electric generator, the kinetic energy of the power module then dives the power module into a bi-level water tank for a subsequent UP portion of the duty cycle. A valve mechanism and a displacement device are submerged in the bi-level tank to cooperate, in combination with each other, to create an unobstructed underwater pathway for the power module through the bi-level tank. The power module then rises under the influence of buoyancy to generate sufficient momentum for exit from the bi-level tank, and a consecutive duty cycle.

A facility for generating electricity includes a hydroelectric generating apparatus including an elongate penstock in flow communication with a source of water and a hydro-turbine and a plurality of water refill pumps for supplying refill water to a plurality of horizontal pistons on a synchronized and coordinated basis to supply pressurized water to the penstock. A pressure regulator is provided for supplying pressurized air to a storage container for supplying air to the pistons and respective air exhaust/release valves release the pressurized air in the pistons to the atmosphere after use. Respective water inflow valves are provided for refilling the pistons after the air exhaust/release valves open.

The present invention relates to a self-powered remote control system for a smart valve, the system comprising: a smart valve for regulating the flow of a fluid in a pipe; a sensing module for sensing the flow rate, pressure, and temperature of the fluid in the pipe; a power generation module for generating power according to the flow of the fluid; a control module for controlling the lifting or lowering of the opening/closing plate of the smart valve according to the flow rate, pressure, or temperature state sensed by the sensing module; and an administrator terminal for transmitting and receiving control signals to and from the control module, wherein the power generation module comprises: a conical fluid guide member provided in a direction in which the fluid is supplied; and a rotating member rotated by the fluid guided through the fluid guide member, whereby the operation of the smart valve can be controlled by manipulating the administrator terminal at a remote location, so as to supply the fluid into the pipe or intercept the supply of the fluid into the pipe.

A first aspect of the invention provides a method of monitoring the condition of a yaw system of a wind turbine, the wind turbine comprising a rotor, the yaw system arranged to control a yaw rotation of the rotor, the method comprising: providing design data 5 representing an expected relationship between yaw moment and yaw rotation speed; measuring a pair of parameters, the pair of parameters comprising a yaw moment parameter indicative of a yaw moment applied to the yaw system, and a yaw rotation speed parameter indicative of a yaw rotation speed caused by the yaw moment; using the design data to evaluate whether the pair of parameters deviates from the expected 10 relationship; and determining a condition of the yaw system on the basis of the evaluation.

A flow control manifold apparatus includes a housing defining a first flow path from a flow input port to flow output port and a second flow path from a return inlet port to a return outlet port. A first flow regulating valve is placed inline the first flow path and an excess flow path fluidly couples the first flow path to the second flow path. An excess pressure valve is placed inline the excess flow path and is in a closed orientation when the first flow regulating valve is open so that all of the fluid exits through the flow output port. The excess pressure valve is then in a partially open orientation when the first flow regulating valve is partially closed so that a first portion of the fluid exits through the flow output port and a second portion of the fluid exits through the return outlet port.

A multi-mode subterranean energy system and a related multi-mode subterranean energy production method are disclosed. The system comprises subterranean tunnels (2, 3, 8, 9, 14) connecting an upper reservoir of water (1), an underground cavity (10) and a subterranean recipient (15), a turbine/pump unit (4), and water flow control means (5, 6, 7). The system optionally can be operated in four modes.

A pumped storage electricity generating system that includes a water feed line for introducing water into a pressure vessel. Water flow valves communicate with the pressure vessel to control introduction of water into the pressure vessel. A push plate is mounted for movement in the pressure vessel between opposed first and second winches adapted for reciprocating the push plate linearly between a first direction wherein water is drawn into the pressure vessel through the water flow valves and a second direction wherein water is conveyed downstream through the water discharge line under pressure to the hydroelectric turbine.

Provided is a wave force utilization unit capable of further reducing product cost and installation cost and effectively utilizing a wave force while decreasing the wave force, and a wave force utilization system in which the unit is used. The wave force utilization unit includes a box-shaped floating unit 1 supported via a support to move in an up-down direction, in response to movement of the sea surface in the up-down direction. The floating unit 1 includes a main body 2, an introduction part 3 disposed continuously on one side of the main body 2, and a water drain part 4 disposed continuously on the other side of the main body 2, the main body 2 includes an air chamber 5 that is a sealed space and acts to float up the floating unit 1, and a flow-through chamber 6 through which seawater flows from the introduction part 3 to the water drain part 4.