A power take-off apparatus for a wave energy converter of point absorber type, includes a cylinder attachable to a floating device, a piston that reciprocates inside the cylinder and has a piston rod attachable to a mooring, at least one penstock with a first end in communication with a second end of the cylinder through a first opening, and a second end having a second opening, and a housing above a cylinder first end. The housing communicates with the penstock through the second opening and with the cylinder through a third opening in the housing such that the cylinder, penstock and the housing form a closed loop for a fluid in the power take-off apparatus. A water turbine is arranged inside the housing so that working fluid entering the housing from the at least one penstock causes rotation of the water turbine to drive an electrical generator connected thereto.

A power take-off apparatus for a wave energy converter of point absorber type, includes a cylinder attachable to a floating device, a piston that reciprocates inside the cylinder and has a piston rod attachable to a mooring, at least one penstock with a first end in communication with a second end of the cylinder through a first opening, and a second end having a second opening, and a housing above a cylinder first end. The housing communicates with the penstock through the second opening and with the cylinder through a third opening in the housing such that the cylinder, penstock and the housing form a closed loop for a fluid in the power take-off apparatus. A water turbine is arranged inside the housing so that working fluid entering the housing from the at least one penstock causes rotation of the water turbine to drive an electrical generator connected thereto.

A circular dam for generating, accumulating, storing, and releasing electrical energy comprises a wall defining a water reservoir built in an abundant body of water such as a sea or an ocean. Water inside the water reservoir is kept at a water level below the water level outside the wall so as to create a water level difference sufficient to operate one or more water turbines positioned across the wall of the water reservoir. Excess electrical energy from other renewable sources of electricity such as wind, solar power, or supplied by a local power grid is used to operate water turbines as water pumps to lower the water level inside the reservoir during times of peak supply of electricity. Water is drained from outside the wall back into the water reservoir to generate electrical energy by flowing over a plurality of water turbines. Generated electricity supplements electrical power for the local power grid during times of high demand.

A circular dam for generating, accumulating, storing, and releasing electrical energy comprises a wall defining a water reservoir built in an abundant body of water such as a sea or an ocean. Water inside the water reservoir is kept at a water level below the water level outside the wall so as to create a water level difference sufficient to operate one or more water turbines positioned across the wall of the water reservoir. Excess electrical energy from other renewable sources of electricity such as wind, solar power, or supplied by a local power grid is used to operate water turbines as water pumps to lower the water level inside the reservoir during times of peak supply of electricity. Water is drained from outside the wall back into the water reservoir to generate electrical energy by flowing over a plurality of water turbines. Generated electricity supplements electrical power for the local power grid during times of high demand.

A multifunctional floating breakwater includes: a plank platform, a first buoy, a second buoy, a first wave baffle, a second wave baffle, a first arc breast wall, a second arc breast wall, upper inclined supports, lower inclined supports and a net cage. The multifunctional floating breakwater integrates a floating breakwater and a wave-energy power generation device, which can not only maintain good stability of the water surface in a harbor, but also generate electric energy, and allow for aquaculture and other activities as well, and has advantages of being movable and not limited by water depth and geology. In addition, the invention has a simple structure, easy production and maintenance, no pollution to the marine environment and therefore wide application prospects.

A fixed permeable breakwater which also serves as a wave power generating device is provided and includes a structure, a structure fixing device and a wave-activated generator set, the structure is connected with seabed through the structure fixing device, holes are arranged on an outer side of upper arc vertical walls of the structure, and spiral vane sets are placed in the holes; a spiral-gear generator is installed on the horizontal bearing plate, and waves push the spiral vane sets to rotate, and then push the spiral-gear generator to generate electricity. The breakwater can be applied to sea areas with deep water, large waves and complex terrain, while reducing the influence of waves and providing a stable water environment for the surrounding sea areas, it has good wave-absorbing performance, convert wave energy into electric energy, and effectively solve the power supply problem of port areas or island residents.

A fixed permeable breakwater which also serves as a wave power generating device is provided and includes a structure, a structure fixing device and a wave-activated generator set, the structure is connected with seabed through the structure fixing device, holes are arranged on an outer side of upper arc vertical walls of the structure, and spiral vane sets are placed in the holes; a spiral-gear generator is installed on the horizontal bearing plate, and waves push the spiral vane sets to rotate, and then push the spiral-gear generator to generate electricity. The breakwater can be applied to sea areas with deep water, large waves and complex terrain, while reducing the influence of waves and providing a stable water environment for the surrounding sea areas, it has good wave-absorbing performance, convert wave energy into electric energy, and effectively solve the power supply problem of port areas or island residents.

A tidal power generation system has a vertical post being embedded in a sea floor and a floating barge operably coupled to the post. The floating barge has a gear rotationally driven by the post as the floating barge moves vertically with respect to the vertical post. An offshore hydraulic pump is operably connected to the gear, an onshore hydraulic motor operably connected to the offshore hydraulic pump by a hydraulic circuit; and an electric generator is operably connected to the onshore hydraulic motor.

A combined sea wave photovoltaic power plant for generating electricity from sea waves and from the sun that includes a pontoon, a jib, a hydro-cylinder, a photovoltaic panel, and conversion system that is designed to be connected to the electricity grid. The photovoltaic panel is assembled on a top of the pontoon and is connected to the conversion systems.

An apparatus and method for extracting energy from an oscillating working fluid, such as ocean waves includes an apparatus (10) having an internal flow passage (40) for the working fluid, a turbine (44) and a flow control device (38), each of the turbine (44) and the flow control device (38) being in direct fluid communication with the flow passage (40), where the flow control device is selectively moveable between a first configuration in which the flow control device is open to allow a flow of the working fluid, such as air, to exit the flow passage therethrough, and a second configuration in which the flow control device restricts a flow of the working fluid therethrough, the working fluid then entering the flow passage via the turbine, which can be harnessed to generate electricity.