Marine-Pumped Hydroelectric Energy Storage

Abstract

In a general aspect, a system stores energy underwater. In sonic aspects, the system includes a base having a bottom side resting on an underwater floor and a top side that includes recessed surfaces. The system also includes domed walls extending from the top side of the base to form respective fluid chambers. Each of the fluid chambers includes an interior volume that is at least partially defined by one of the recessed surfaces and an interior surface of one of the domed walls. The system additionally includes a pump and a generator. The pump is configured to transport water from the fluid chambers toward an exterior environment of the system. The generator is configured to generate electrical energy in response to water flowing from the exterior environment toward the fluid chambers.

1 . A system for storing energy underwater, comprising:
 a base having a bottom side resting on an underwater floor and a top side comprising a plurality of recessed surfaces;   a plurality of domed walls extending from the top side of the base to form respective fluid chambers, each of the fluid chambers comprising an interior volume that is at least partially defined by one of the recessed surfaces and an interior surface of one of the domed walls;   a pump configured to pump water from the fluid chambers toward an exterior environment of the system; and   a generator configured to generate electrical energy in response to water flowing from the exterior environment into the fluid chambers.   
     
     
         2 . The system of  claim 1 , comprising:
 a conduit system configured to provide fluid communication between the fluid chambers.   
     
     
         3 . (canceled) 
     
     
         4 . The system of  claim 2 , wherein the conduit system defines at least part of a flow path that extends between the fluid chambers and the exterior environment of the system. 
     
     
         5 . The system of  claim 2 , wherein the recessed surfaces of the base define respective conduit ports to the conduit system. 
     
     
         6 . The system of  claim 1 , wherein the base and the plurality of domed walls are an integral body. 
     
     
         7 . The system of  claim 1 ,
 wherein the base and the plurality of domed walls are separate bodies; and   wherein each of the domed walls comprises a perimeter edge that encircles an opening of the domed wall, the perimeter edge sealed to the top side of the base.   
     
     
         8 . The system of  claim 1 , comprising:
 a pump housing containing the pump and coupled to the base, the pump housing comprising first and second pump housing ports; and   a generator housing containing the generator and coupled to the base, the generator housing comprising first and second generator housing ports.   
     
     
         9 . The system of  claim 8 ,
 wherein a first flow path extends between the fluid chambers and the exterior environment of the system and comprises at least a portion extending through the pump housing between the first and second pump housing ports;   wherein the pump is configured to pump water along the first flow path from the fluid chambers toward the exterior environment;   wherein a second flow path extends between the fluid chambers and the exterior environment of the system and comprises at least a portion extending through the generator housing between the first and second generator housing ports, the second flow path distinct from the first flow path; and   wherein the generator is configured to generate electrical energy in response to water flowing along the second flow path from the exterior environment toward the fluid chambers.   
     
     
         10 . The system of  claim 1 , comprising:
 a housing containing a combined pump/generator assembly that comprises the pump and the generator, the housing coupled to the base and comprising first and second housing ports.   
     
     
         11 . The system of  claim 10 ,
 wherein a third flow path extends between the fluid chambers and the exterior environment of the system and comprises at least a portion extending through the housing between the first and second housing ports;   wherein the pump is configured to pump water along the third flow path from the fluid chambers toward the exterior environment;   wherein the generator is configured to generate electrical energy in response to water flowing along the third flow path from the exterior environment into the fluid chambers.   
     
     
         12 . The system of  claim 1 , comprising an anchor coupling the base to the underwater floor. 
     
     
         13 . The system of  claim 1 , wherein the base comprises a pocket configured to hold ballast material, the pocket having an opening accessible from an exterior of the base. 
     
     
         14 . The system of  claim 1 , comprising an electrical cable that communicates electrical power between an onshore electrical system and one or both of the pump and the generator. 
     
     
         15 . The system of  claim 1 , comprising an electrical cable that communicates electrical power between an offshore platform and one or both of the pump and the generator. 
     
     
         16 . A method comprising:
 pumping water from fluid chambers of an underwater energy storage system to an exterior environment of the underwater energy storage system, the underwater energy storage system comprising:
 a base having a bottom side resting on an underwater floor and a top side comprising a plurality of recessed surfaces, and 
 a plurality of domed walls extending from the top side of the base to form respective instances of the fluid chambers, each of the fluid chambers comprising an interior volume that is at least partially defined by one of the recessed surfaces and an interior surface of one of the domed walls; and 
   generating electrical energy in response to water flowing from the exterior environment into the fluid chambers.   
     
     
         17 . The method of  claim 16 ,
 wherein the exterior environment comprises water having a hydrostatic pressure; and   wherein pumping water comprises transporting the water into the exterior environment against the hydrostatic pressure to store energy.   
     
     
         18 . The method of  claim 16 ,
 wherein the exterior environment comprises water having a hydrostatic pressure; and   wherein generating electrical energy comprises driving water into the fluid chambers by action of the hydrostatic pressure.   
     
     
         19 . The method of  claim 16 , wherein the underwater energy storage system comprises a conduit system configured to provide fluid communication between the fluid chambers. 
     
     
         20 . The method of  claim 19 ,
 wherein pumping water comprises transporting water through the conduit system from the fluid chambers towards the exterior environment; and   wherein generating electrical energy comprises transporting water through the conduit system from the exterior environment towards the fluid chambers.   
     
     
         21 . The method of  claim 16 ,
 wherein pumping water comprises transporting water along a first flow path from the fluid chambers toward the exterior environment;   wherein generating electrical energy comprises generating electrical energy in response to water flowing along a second flow path from the exterior environment toward the fluid chambers; and   wherein the first and second flow paths are distinct from each other.   
     
     
         22 . The method of  claim 16 ,
 wherein pumping water comprises transporting water along a first flow path from the fluid chambers toward the exterior environment;   wherein generating electrical energy comprises generating electrical energy in response to water flowing along a second flow path from the exterior environment toward the fluid chambers; and   wherein the first and second flow paths are the same flow path.   
     
     
         23 . The method of  claim 16 , wherein pumping water comprises:
 supplying electrical energy to a pump, thereby energizing the pump to transport the water from the fluid chambers to the exterior environment.   
     
     
         24 . The method of  claim 23 , wherein supplying the electrical energy comprises:
 receiving, at a transformer, electrical energy from a source of electrical energy; and   transforming, by operation of the transformer, the received electrical energy to produce the supplied electrical energy.   
     
     
         25 . The method of  claim 16 , comprising:
 providing, through an electrical cable, the generated electrical energy to an electrical system.   
     
     
         26 . The method of  claim 25 , wherein providing the generated electrical energy comprises:
 receiving, at a transformer, the generated electrical energy; and   transforming, by operation of the transformer, a voltage, a current, or a phase of the generated electrical energy.   
     
     
         27 . The method of  claim 25 ,
 wherein the electrical system is disposed at an onshore location; and   wherein providing the generated electrical energy comprises transferring the generated electrical energy to the onshore location.   
     
     
         28 . The method of  claim 25 ,
 wherein the electrical system is disposed on an offshore platform; and   wherein providing the generated electrical energy comprises transferring the generated electrical energy to the offshore platform.   
     
     
         29 . The system of  claim 2 , wherein the base comprises the conduit system. 
     
     
         30 . The system of  claim 29 , wherein the base comprises interior surfaces that define the conduit system. 
     
     
         31 . The method of  claim 19 , wherein the base comprises the conduit system. 
     
     
         32 . The method of  claim 19 , wherein the conduit system defines at least part of a flow path that extends between the two or more fluid chambers and the exterior environment.