An algae cultivation system includes generating a translating hydraulic jump wave that travels across a gas-liquid interface of an algae cultivation fluid contained in the algae cultivation system. The translating hydraulic jump wave has Froude number greater than 1.

According to one embodiment, a pumped-storage power generation control device includes a control section that controls at least one of the pumping input of the pumped-storage power generation facility in the pumping operation and the power output of the pumped-storage power generation facility in the power generating operation such that a value, which is obtained by a predetermined calculation using the measurement value relating to the pumping input of the pumped-storage power generation facility in the pumping operation and the measurement value relating to the power output of the pumped-storage power generation facility in the power generating operation, becomes a set target value.

According to one embodiment, a pumped-storage power generation control device includes a control section that controls at least one of the pumping input of the pumped-storage power generation facility in the pumping operation and the power output of the pumped-storage power generation facility in the power generating operation such that a value, which is obtained by a predetermined calculation using the measurement value relating to the pumping input of the pumped-storage power generation facility in the pumping operation and the measurement value relating to the power output of the pumped-storage power generation facility in the power generating operation, becomes a set target value.

An underwater turbo-generator unit for producing electrical power has a pressure-resistant shell that defines a sealed internal chamber. At least one water inlet extends through the shell to effect fluid communication between the chamber and a body of water surrounding the shell. A turbine is supported within the chamber to turn on a spin axis in response to admission of a flow of water into the chamber via the or each water inlet. The shell can be arranged to maintain a gas-filled space within the chamber, facilitating the use of a Felton turbine that turns about a vertical spin axis. The or each water inlet communicates with at least one tubular penstock structure that can be supported by the unit outside the shell. The chamber communicates with, and drains water into, a fluid storage volume such as a pipeline positioned at a level beneath the chamber.

An underwater turbo-generator unit for producing electrical power has a pressure-resistant shell that defines a sealed internal chamber. At least one water inlet extends through the shell to effect fluid communication between the chamber and a body of water surrounding the shell. A turbine is supported within the chamber to turn on a spin axis in response to admission of a flow of water into the chamber via the or each water inlet. The shell can be arranged to maintain a gas-filled space within the chamber, facilitating the use of a Felton turbine that turns about a vertical spin axis. The or each water inlet communicates with at least one tubular penstock structure that can be supported by the unit outside the shell. The chamber communicates with, and drains water into, a fluid storage volume such as a pipeline positioned at a level beneath the chamber.

A system and method of combining pumped hydro and thermal energy storage is disclosed that has upper and lower fluid storage reservoirs. The reservoirs are used as a pumped energy storage system in which excess electrical power is stored as gravitational potential energy by using it to transfer fluid up to the upper one. At a later time, the fluid is run back down through a turbine under the force of gravity to generate electricity. Either, or both, fluid storage regions are also used to store thermal energy transferred into the stored fluid via liquid-to-liquid heat exchangers. The stored thermal energy is later extracted out to be distributed in for use in either directly heating structures or to improve the heating efficiency of one or more heat pumps in a district heating system. The fluid may be water, or it may be any suitable high-density fluid such as drilling mud.

A system and method of combining pumped hydro and thermal energy storage is disclosed that has upper and lower fluid storage reservoirs. The reservoirs are used as a pumped energy storage system in which excess electrical power is stored as gravitational potential energy by using it to transfer fluid up to the upper one. At a later time, the fluid is run back down through a turbine under the force of gravity to generate electricity. Either, or both, fluid storage regions are also used to store thermal energy transferred into the stored fluid via liquid-to-liquid heat exchangers. The stored thermal energy is later extracted out to be distributed in for use in either directly heating structures or to improve the heating efficiency of one or more heat pumps in a district heating system. The fluid may be water, or it may be any suitable high-density fluid such as drilling mud.

Aspects of the disclosure provide a power conversion system and a method for conversing power. The power conversion system includes a first fluid holding tank, a second fluid holding tank, a fluid inlet hose, a fluid outlet hose, a fluid container, and one or more tension springs connected to the upper surface of the container and to a lower surface of the first fluid holding tank. The power conversion system further includes a rotational component connected to a lower side of the container via a connecting rod. The power conversion system further includes a generator connected to the rotational component via a horizontal shaft. The power conversion system further includes a feedback hose connected between the second fluid holding tank and the first fluid holding tank. The power conversion system further includes a hydraulic pump connected to the second fluid holding tank.

Aspects of the disclosure provide a power conversion system and a method for conversing power. The power conversion system includes a first fluid holding tank, a second fluid holding tank, a fluid inlet hose, a fluid outlet hose, a fluid container, and one or more tension springs connected to the upper surface of the container and to a lower surface of the first fluid holding tank. The power conversion system further includes a rotational component connected to a lower side of the container via a connecting rod. The power conversion system further includes a generator connected to the rotational component via a horizontal shaft. The power conversion system further includes a feedback hose connected between the second fluid holding tank and the first fluid holding tank. The power conversion system further includes a hydraulic pump connected to the second fluid holding tank.

A hydropower system for generating and storing energy is disclosed. The system comprises an upper (1) and a lower (2) level reservoir, and an electromechanical system (12) arranged in the lower level reservoir and in hydraulic connection with the upper level reservoir. A related method generating and storing energy is also disclosed.