A hydroelectric power generation system includes at least one penstock extending through the sea floor a predetermined depth into the ground below the sea floor, a turbine connected to an underground distal end of each of the at least one penstock, and an underground reservoir to collect seawater flowing down through the at least one penstock and the connected turbine. The hydroelectric power generation system may be part of a distributed hydroelectric power generation system which includes a plurality of hydroelectric power generation systems, the distributed hydroelectric power generation system additionally including an underground reservoir to collect seawater flowing down through all of the penstocks and connected turbines in the plurality of hydroelectric power systems.

A hydroelectric power generation system includes at least one penstock extending through the sea floor a predetermined depth into the ground below the sea floor, a turbine connected to an underground distal end of each of the at least one penstock, and an underground reservoir to collect seawater flowing down through the at least one penstock and the connected turbine. The hydroelectric power generation system may be part of a distributed hydroelectric power generation system which includes a plurality of hydroelectric power generation systems, the distributed hydroelectric power generation system additionally including an underground reservoir to collect seawater flowing down through all of the penstocks and connected turbines in the plurality of hydroelectric power systems.

The invention relates to energy generation and water conservation. There are many water systems which might lend themselves to energy extraction, such as canal systems. However, despite canal systems being around for hundreds of years, practical solutions for using the energy available have not been developed. The invention provides, among various examples, a system which can be associated with a lock in a canal and provides a flow control strategy responsive to water availability upstream of the lock. Thus electricity may be generated selectively in response to the lock state and energy demands but without adversely affecting the canal system by taking excess water. The system may be applied to multiple locks and may incorporate machine learning to evolve a strategy for a canal based on lock usage and energy demand.

The invention relates to energy generation and water conservation. There are many water systems which might lend themselves to energy extraction, such as canal systems. However, despite canal systems being around for hundreds of years, practical solutions for using the energy available have not been developed. The invention provides, among various examples, a system which can be associated with a lock in a canal and provides a flow control strategy responsive to water availability upstream of the lock. Thus electricity may be generated selectively in response to the lock state and energy demands but without adversely affecting the canal system by taking excess water. The system may be applied to multiple locks and may incorporate machine learning to evolve a strategy for a canal based on lock usage and energy demand.

A hydroelectric energy production and storage system comprising an upper reservoir located in a depression or cavity in the ground and a lower reservoir located underground, where objects are arranged in the depression or cavity forming an aggregate which fills the depression or cavity and comprises hydraulically communicating void volumes between the objects is disclosed. Further, a method for building and operating such a system is presented.

A hydroelectric energy production and storage system comprising an upper reservoir located in a depression or cavity in the ground and a lower reservoir located underground, where objects are arranged in the depression or cavity forming an aggregate which fills the depression or cavity and comprises hydraulically communicating void volumes between the objects is disclosed. Further, a method for building and operating such a system is presented.

A water reservoir system for generating, accumulating, storing, and releasing electrical energy comprises a reservoir wall built in a shallow body of water such as a sea or an ocean with a height exceeding the outside water level by about 10-25 m, thereby defining an interior 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 pumps to fill the interior of the water reservoir with water during times of peak supply of electricity. Water is drained from the water reservoir to the outside body of water and generates electrical energy by flowing over a plurality of water turbines, thereby generating electricity and supplementing electrical power for the local power grid during times of high demand. Additional interior sources of renewable energy may be used to supplement external sources of electrical power in operating the system of the invention.

A water reservoir system for generating, accumulating, storing, and releasing electrical energy comprises a reservoir wall built in a shallow body of water such as a sea or an ocean with a height exceeding the outside water level by about 10-25 m, thereby defining an interior 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 pumps to fill the interior of the water reservoir with water during times of peak supply of electricity. Water is drained from the water reservoir to the outside body of water and generates electrical energy by flowing over a plurality of water turbines, thereby generating electricity and supplementing electrical power for the local power grid during times of high demand. Additional interior sources of renewable energy may be used to supplement external sources of electrical power in operating the system of the invention.

A floating power-generation group comprises a floating hub such as a spar buoy that is anchored to subsea foundations by anchor lines. Floating power producer units such as wind turbines are connected electrically and mechanically to the hub. The power producer units are each moored by mooring lines. At least one mooring line extends inwardly toward the hub to effect mechanical connection to the hub and at least one other mooring line extends outwardly toward a subsea foundation. The groups are combined as a set whose hubs are connected electrically to each other via subsea energy storage units. Anchor lines of different groups can share subsea foundations. The storage units comprise pumping machinery to expel water from an elongate storage volume and generating machinery to generate electricity from a flow of water entering the storage volume. The pumping machinery may be in deeper water than the generating machinery.

An aquifer storage and recovery system can include a pump, an electric motor coupled to the pump, a drive unit configured to control operation of the electric motor, and a controller. The controller can be configured to flow water into a well bore from a source reservoir through the pump such that the pump rotates in a reverse direction and drives the electric motor coupled to the pump in the reverse direction to operate as a generator, determine a power output of the electric motor, determine a difference between the power output of the electric motor and a power output set point, and operate the drive unit to control a rotational speed of the electric motor based at least in part on the difference between the power output of the electric motor and the power output set point.