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.

In one embodiment, a renewable energy generation and storage system and method is provided for storing both electrical and thermal energy that includes a forward osmosis system for drawing water across a membrane such that the water drawn across the membrane is used to dilute an osmotic ionic draw solution and the diluted osmotic ionic draw solution is used to drive a hydro-turbine; an FO-EED separation system for separating the drawn water from the ionic draw solution using renewable electrical energy and an osmotic polymer introduced in the FO-EED system during use, so that the ionic draw solution is re-concentrated by using electrical energy, such that the water from the ionic solution combines with the concentrated osmotic polymer; a coalescer configured to receive compressed CO.sub.2 to separate the water from the polymer by having the polymer absorb the compressed CO.sub.2 during use; and using thermal energy for separating the CO.sub.2 from the polymer, thereby regenerating a concentrated polymer solution.

A desalination system includes a vertical column with a lower end submerged into a body of liquid to be treated. The column has a dark-colored outer surface able to absorb electromagnetic energy, and at least one vacuum compressor is connected to provide a vacuum pressure in the vertical column such that the liquid is drawn into the vertical column through openings in the vertical column. A condensing dome has a main shell and that receives vapor of the liquid in the vertical column via a vapor port joining the vertical column and the condensing dome. A wind-driven outer turbine surrounds the main shell of the condensing dome and draws outside air into a space around the main shell of the condensing dome. A tank is connected to the condensing dome via a pipe and receives desalinated liquid from the condensing dome.

A device for sea water desalination and power generation, including: a tidal current turbine, a coupling, a revolving shaft, a booster pump, and a body. The body includes a chamber, a divider, and an end cover. The divider and the end cover are in fixed connection to the body, and the divider divides the chamber into a closed pumping chamber and a closed desalination and power generation chamber. The booster pump is disposed in the pumping chamber and is driven by the revolving shaft. The tidal current turbine is connected to the revolving shaft via the coupling. The desalination and power generation chamber includes a seawater pretreatment device, a seawater desalinating unit including an unsteady reverse osmosis membrane, a flow battery, and a controller. The booster pump is connected to the seawater pretreatment device via an inlet tube, and is connected to the seawater desalinating unit via an outlet tube.

An offshore compressed air energy storage system has a barge comprising with a deck, and at least one pressure vessel configured to store compressed air. A power source powers at least one air compressor configured to pressurize the pressure vessel. A compander set has at least one turboexpander having an input, an output, and a shaft, as well as at least one heat exchanger and at least one turbocompressor. A mass air control valve is configured to control the compressed air flow from the pressure vessel to the turboexpander. A generator is in communication with the shaft of the turboexpander, and a control system. The at least one pressure vessel is buoyant, and wherein the at least one air compressor, the turboexpander, the mass air control valve, and the generator are attached to the barge.

An energy storage system employing a reversible salination-desalination process includes an electrochemical desalination battery (EDB) unit including an anode and a cathode. The EDB unit runs a salination process while storing energy from a direct current power supply unit, and runs a desalination process while releasing energy to an electrical load. The energy storage system can store power from a variable output electrical power supply unit such as solar cells and wind turbines while running a salination process, and release energy, e.g., during peak energy demand hours while running a desalination process. Combined with a capacitive deionization (CD) unit, the energy storage system can generate fresh water by running desalination processes in the EDB unit and the CD unit while releasing stored energy from the EDB unit. The energy storage unit can function as a dual purpose device for energy storage and fresh water generation.

Energy may be stored by injecting fluid into a fracture in the earth and producing the fluid back while recovering power and/or desalinating water. The method may be particularly adapted to storage of large amounts of energy such as in grid-scale electric energy systems. The fracture may be formed and treated with resin so as to limit fluid loss and to increase propagation pressure. The fluid may be water containing a dissolved salt or fresh water and a portion or all of the water may be desalinated using pressure in the water when it is produced.

A gravity power and desalination technology system is provided, including a heat storage apparatus, an inner tube portion, a hot-air and vapor generator, and venting holes, a corrugated tube portion, an outer tube portion, an updraft wind power generator, and an artificial hydro power generator. The heat storage apparatus is provided in a lower portion and configured. The inner tube portion has an inner vent portion inside and disposed vertically over the heat storage apparatus. The hot-air and vapor generator is disposed between the heat storage apparatus and the inner tube portion. The venting holes are bored through the inner tube portion obliquely outwards. The corrugated tube portion is provided on a top portion of the outer tube portion. The updraft wind power generator and the artificial hydro power generator are installed in the lower portions of the inner vent portion and the outer vent portion, respectively.