Abstract: Embodiments of the present invention relate to compressed gas storage units, which in certain applications may be employed in conjunction with energy storage systems. Some embodiments may comprise one or more blow-molded polymer shells, formed for example from polyethylene terephthalate (PET) or ultra-high molecular weight polyethylene (UHMWPE). Embodiments of compressed gas storage units may be composite in nature, for example comprising carbon fiber filament(s) wound with a resin over a liner. A compressed gas storage unit may further include a heat exchanger element comprising a heat pipe or apparatus configured to introduce liquid directly into the storage unit for heat exchange with the compressed gas present therein.

Abstract: Embodiments relate generally to energy storage systems, and in particular to energy storage systems using compressed gas as an energy storage medium. In various embodiments, a compressed gas storage system may include a plurality of stages to convert energy into compressed gas for storage, and then to recover that stored energy by gas expansion. In certain embodiments, a stage may comprise a reversible compressor/expander having a reciprocating piston. Pump designs for introducing liquid for heat exchange with the gas, are described. Gas flow valves featuring shroud and/or curtain portions, are also described.

Abstract: Embodiments relate to valves comprising a member such as a plate or poppet, that is moveable relative to a stationary seat. The state of the member may be maintained against opposing forces with relatively little expenditure of energy. According to one embodiment, a poppet displaced from seating in the valve seat, may be held in position against opposing forces tending to close the valve, until a desired flow of gas through the valve has taken place. The poppet may then be released as desired, such that those opposing forces serve to passively close the valve. The valve may be secured in position utilizing mechanical, magnetic, electromagnetic, pneumatic, electrostatic, or hydraulic approaches. Valve embodiments may be particularly suited to controlling gas flows for compression and/or expansion in an energy storage system.

Abstract: A hybrid solar concentrator that utilizes one or more dielectric mirrors to isolate components of the solar spectrum compatible with specific PV band-gaps and to pass longer wavelengths through to a heat receiver, generating both electricity and heat from a single set of dual-axis heliostats.

Abstract: An energy storage and recovery system employs air compressed utilizing power from an operating wind turbine. This compressed air is stored within one or more chambers of a structure supporting the wind turbine above the ground. By functioning as both a physical support and as a vessel for storing compressed air, the relative contribution of the support structure to the overall cost of the energy storage and recovery system may be reduced, thereby improving economic realization for the combined turbine/support apparatus. In certain embodiments, expansion forces of the compressed air stored within the chamber, may be relied upon to augment the physical stability of a support structure, further reducing material costs of the support structure.

Abstract: Embodiments relate to valves comprising a member such as a plate or poppet, that is moveable relative to a stationary seat. The state of the member may be maintained against opposing forces with relatively little expenditure of energy. According to one embodiment, a poppet displaced from seating in the valve seat, may be held in position against opposing forces tending to close the valve, until a desired flow of gas through the valve has taken place. The poppet may then be released as desired, such that those opposing forces serve to passively close the valve. The valve may be secured in position utilizing mechanical, magnetic, electromagnetic, pneumatic, electrostatic, or hydraulic approaches. Valve embodiments may be particularly suited to controlling gas flows for compression and/or expansion in an energy storage system.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: Embodiments of the present invention relate to compressed gas storage units, which in certain applications may be employed in conjunction with energy storage systems. Some embodiments may comprise one or more blow-molded polymer shells, formed for example from polyethylene terephthalate (PET) or ultra-high molecular weight polyethylene (UHMWPE). Embodiments of compressed gas storage units may be composite in nature, for example comprising carbon fiber filament(s) wound with a resin over a liner. A compressed gas storage unit may further include a heat exchanger element comprising a heat pipe or apparatus configured to introduce liquid directly into the storage unit for heat exchange with the compressed gas present therein.

Abstract: Embodiments relate generally to energy storage systems, and in particular to energy storage systems using compressed gas as an energy storage medium. In various embodiments, a compressed gas storage system may include a plurality of stages to convert energy into compressed gas for storage, and then to recover that stored energy by gas expansion. In certain embodiments, a stage may comprise a reversible compressor/expander having a reciprocating piston. Pump designs for introducing liquid for heat exchange with the gas, are described. Gas flow valves featuring shroud and/or curtain portions, are also described.

Abstract: Embodiments of the present invention use compressed air to store and deliver electrical, mechanical, and/or thermal power with high round-trip efficiency. Various embodiments may be scalable for use in a variety of environments—from wind farms to power plants to motor vehicles. An energy storage system according to the present invention can operate as a stand-alone storage system that connects electrically to the grid, it can be tightly integrated with a wind turbine, and/or it can be co-located with a thermal power generation facility and operate with even higher efficiency by scavenging low-grade waste heat.

Abstract: An energy storage and recovery system employs air compressed utilizing power from an operating wind turbine. This compressed air is stored within one or more chambers of a structure supporting the wind turbine above the ground. By functioning as both a physical support and as a vessel for storing compressed air, the relative contribution of the support structure to the overall cost of the energy storage and recovery system may be reduced, thereby improving economic realization for the combined turbine/support apparatus. In certain embodiments, expansion forces of the compressed air stored within the chamber, may be relied upon to augment the physical stability of a support structure, further reducing material costs of the support structure.

Abstract: An apparatus performs a power cycle involving expansion of compressed air utilizing high pressure (HP) and low pressure (LP) air turbines located upstream of a gas turbine. The power cycle involves heating of the compressed air prior to its expansion in the HP and LP air turbines. Taking into consideration fuel consumption to heat the compressed air, particular embodiments may result in a net production of electrical energy of ˜2.2-2.5× an amount of energy consumed by substantially isothermal air compression to produce the compressed air supply. Although pressure of the compressed air supply may vary over a range (e.g. as a compressed air storage unit is depleted), the gas turbine may run under almost constant conditions, facilitating its integration with the apparatus. The air turbines may operate at lower temperatures than the gas turbine, and they may include features of turbines employed to turbocharge large reciprocating engines.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: An expansion system utilizes external combustion of its residual warm exhaust air, in order to heat incoming compressed air. The heat of this external combustion is communicated to the incoming compressed air through a heat exchanger. The expansion system may be incorporated into an energy storage device also featuring a compressed air storage unit supplied by a compressor. Where the stored supply of compressed air is depleted, the energy storage device may continue to supply electricity on demand through operation as a heat engine, with the compressor being driven directly (e.g. on a same rotating shaft) or indirectly (via generated electrical power) by the expansion system. Multiple expanders of the same or different types (e.g. rotating, reciprocating), may be utilized in parallel and/or in series (e.g. multiple stages) depending upon the particular application. Multi-stage embodiments featuring internal combustion in low pressure stages, may be particularly suited for placement in vehicles.