Renewable Energy Storage Methods and Systems

Abstract

In one embodiment, a renewable energy storage system includes a forward osmosis system, a hydro-turbine, and a separation (e.g., CEDI) system powered by one or more natural regenerating energy sources, such as wind or solar. In another embodiment, a renewable energy storage system includes a forward osmosis system, a hydro-turbine, a solar thermal heat exchanger through which the diluted osmotic draw solution can be directed for purposes of heating up the draw solution, and a solvent-water separator configured to separate the draw solution from the water. One example method includes drawing water across a forward osmosis membrane in a forward osmosis system such that the water drawn across the membrane dilutes an osmotic draw solution; directing the diluted osmotic draw solution to drive a hydro-turbine to produce energy; and separating the water from the draw solution using one or more natural regenerating energy sources.

What is claimed is: 
     
         1 . A renewable energy storage system comprising:
 a forward osmosis system for drawing water across a membrane such that, when in use, the water drawn across the membrane is used to dilute an osmotic draw solution and the diluted osmotic draw solution is used to drive a hydro-turbine to produce energy;   a hydro-turbine driven by the diluted draw solution when in use, and   a separation system for separating the drawn water from the draw solution, the separation system powered by one or more natural regenerating energy sources, so that the draw solution can be re-directed to the forward osmosis system and the water can be reused to be drawn across the forward osmosis membrane.   
     
     
         2 . The renewable energy storage system of  claim 1 , wherein the separation system comprises an electro-deionization system. 
     
     
         3 . The renewable energy storage system of  claim 2 , wherein the electro-deionization system comprises a continuous electro-deionization system. 
     
     
         4 . The renewable energy storage system of  claim 1 , wherein the one or more natural regenerating energy sources comprises either solar energy and/or wind energy. 
     
     
         5 . The renewable energy storage system of  claim 1 , further comprising a second hydro-turbine. 
     
     
         6 . The renewable energy storage system of  claim 1 , wherein the draw solution comprises one or more ionic osmotic solutions. 
     
     
         7 . The renewable energy storage system of  claim 6 , wherein the ionic osmotic solution comprises magnesium chloride and/or ammonia chloride. 
     
     
         8 . The renewable energy storage system of  claim 1 , wherein the forward osmosis system comprises a pressure-retarded forward osmosis system. 
     
     
         9 . A renewable energy storage system comprising:
 a forward osmosis system for drawing water across a membrane such that, when in use, the water drawn across the membrane is used to dilute an osmotic draw solution and the diluted osmotic draw solution is used to drive a hydro-turbine to produce energy;   a hydro-turbine driven by the diluted draw solution when in use;   a solar thermal heat exchanger through which the diluted osmotic draw solution can be directed for purposes of heating up the draw solution to cause substantial separation of the draw solution from the water, and   a solvent-water separator configured to separate the draw solution from the water so that the draw solution can be re-directed to the forward osmosis system and the water can be reused to be drawn across the forward osmosis membrane.   
     
     
         10 . The renewable energy storage system of  claim 9 , further comprising a second hydro-turbine. 
     
     
         11 . The renewable energy storage system of  claim 9 , wherein the forward osmosis system comprises a pressure-retarded forward osmosis system. 
     
     
         12 . The renewable energy storage system of  claim 9 , wherein the draw solution comprises a cloud point osmotic solution. 
     
     
         13 . The renewable energy storage system of  claim 12 , wherein the cloud point osmotic solution comprises one or more cloud point glycols. 
     
     
         14 . A method of storing renewable energy comprising:
 drawing water across a forward osmosis membrane in a forward osmosis system such that the water drawn across the membrane dilutes an osmotic draw solution;   directing the diluted osmotic draw solution to drive a hydro-turbine to produce energy; and   separating the water from the draw solution using one or more natural regenerating energy sources so that the draw solution can be re-directed to the forward osmosis system and the water can be reused to be drawn across the forward osmosis membrane.   
     
     
         15 . The method of storing renewable energy of  claim 14 , wherein separating the water from the draw solution comprises directing the diluted draw solution into a CEDI system powered by the one or more natural regenerating energy sources. 
     
     
         16 . The method of storing renewable energy of  claim 15 , wherein the one or more natural regenerating energy sources comprises either solar energy and/or wind energy. 
     
     
         17 . The method of storing renewable energy  claim 14 , wherein separating the water from the draw solution comprises directing the diluted draw solution through a solar thermal heat exchanger for purposes of heating up the draw solution to cause substantial separation of the draw solution from the water, and then directing the diluted draw solution into a a solvent-water separator configured to separate the draw solution from the water. 
     
     
         18 . The method of storing renewable energy of  claim 14 , further comprising directing the water through a second hydro-turbine before re-directing the water to the forward osmosis system. 
     
     
         19 . The method of storing renewable energy of  claim 14 , wherein the forward osmosis system comprises a pressure-retarded forward osmosis system. 
     
     
         20 . The method of storing renewable energy of  claim 14 , wherein the draw solution comprises one or more ionic osmotic solutions or one or more cloud point osmotic solutions.