Device (1) for storing electric energy, comprising a heat reaction chamber (3) comprising a metal carbonate or a metal hydride material, a gas storage (4) and an electric heater (5) adapted to heat the reaction chamber (3), a Stirling engine (7) comprising a heater head (8) and adapted to be powered by the heat reaction chamber (3), a generator (9) connected to and adapted to be driven by the Stirling engine (7), where the device is provided with a compressor (11) arranged downstream of the reaction chamber (3) and upstream of the gas storage (4) adapted to increase the pressure of the gas flowing into the gas storage (4) from the reaction chamber (3), and a pressure relief valve (10) arranged downstream of the gas storage (4) and upstream of the heat reaction chamber (3) adapted to control the pressure of the gas flowing into the reaction chamber (3) from the gas storage (4). The advantage of the invention is that a reliable and cost-effective storage device for renewable electric energy is provided.

Automatic wind and photovoltaic energy storage system for generation of uninterrupted electricity and energy autonomy, characterized in that it consists of wind machines (A) and photovoltaic generators (B) combined or independent which operate mechanically or electrically connected suitable compressors (Γ1, Γ2, Γ3, Γ4) that compress air at high pressure while simultaneously removing the heat generated by compression with small heat exchangers (E1, E2, E3, E4), by heating diathermic cooling oil and water stored in separate insulated tanks (H1, H2, H3, Z2) they drive it to an airtight tank-serpentine coil type tank (M), where it exits and after passing through the air flow distributor in each group of high pressure crosses the groups of heat exchangers (θ1) in which the flow flows backwards cooling oil, where its thermal charge is transferred and heats the compressed air before entering the gas turbine and expands to a certain pressure lower and temperature lower the original T2. At this point the compressed air flows coming out of the turbine and reheats in the same way as in the first re-heat, that is, by crossing another set of heat exchangers (02) similar to the first one, but at a lower pressure and re-introducing at the same pressure it exited but at the same temperature as the original Ti. To expanding again to a given pressure corresponding to the next stage according to the thermodynamic analysis. The expansion continues with the intermediate reheats according to the specified stages of the thermodynamic analysis, until after the last reheat in the last stage, inject the quantity of water vapor (steam) stored in a separate insulated tank (Z2) into the flow of compressed air expanding the common fluid (compressed air plus steam) at the same pressure and temperature into the turbine (K), achieving approximately a 20% increase in the overall turbine (K) efficiency. The turbine is equipped, by means of a rotary shaft rotary controller, to be able to modulate the supply of compressed air to the turbine head (K). And since the mass flow rate of compressed air is directly proportional to the electricity produced, the generation of electricity produced is identical to the demand Automatic wind and photovoltaic energy storage system for generation of uninterrupted electricity and energy autonomy, characterized in that it consists of wind machines (A) and photovoltaic generators (B) combined or independent which operate mechanically or electrically connected suitable compressors (IT, Γ2,Γ3,Γ4) that compress air at high pressure while simultaneously removi

In a main flow passage, a first heat exchanger, a first heat storage unit, a second heat exchanger, and a second heat storage unit are connected by a heating medium flow passage. The main flow passage allows a heating medium to be circulated. A sub flow passage includes a shortened flow passage which is a part of the heating medium flow passage and branches from the heating medium flow passage between the second heat exchanger and the second heat storage unit and extends to the first heat storage unit. The sub flow passage allows circulation of the heating medium between the first heat storage unit and the second heat exchanger. A first heating means in a middle of the shortened flow passage, the first heating means heating a passing heat medium, and a switching means conducting switching between the main flow passage and the sub flow passage are provided.

In a main flow passage, a first heat exchanger, a first heat storage unit, a second heat exchanger, and a second heat storage unit are connected by a heating medium flow passage. The main flow passage allows a heating medium to be circulated. A sub flow passage includes a shortened flow passage which is a part of the heating medium flow passage and branches from the heating medium flow passage between the second heat exchanger and the second heat storage unit and extends to the first heat storage unit. The sub flow passage allows circulation of the heating medium between the first heat storage unit and the second heat exchanger. A first heating means in a middle of the shortened flow passage, the first heating means heating a passing heat medium, and a switching means conducting switching between the main flow passage and the sub flow passage are provided.

A thermal storage subsystem may include at least a first storage reservoir configured to contain a thermal storage liquid at a storage pressure that is greater than atmospheric pressure. A liquid passage may have an inlet connectable to a thermal storage liquid source and configured to convey the thermal storage liquid to the liquid reservoir. A first heat exchanger may be provided in the liquid inlet passage and may be in fluid communication between the first compression stage and the accumulator, whereby thermal energy can be transferred from a compressed gas stream exiting a gas compressor/expander subsystem to the thermal storage liquid.

A thermal storage subsystem may include at least a first storage reservoir configured to contain a thermal storage liquid at a storage pressure that is greater than atmospheric pressure. A liquid passage may have an inlet connectable to a thermal storage liquid source and configured to convey the thermal storage liquid to the liquid reservoir. A first heat exchanger may be provided in the liquid inlet passage and may be in fluid communication between the first compression stage and the accumulator, whereby thermal energy can be transferred from a compressed gas stream exiting a gas compressor/expander subsystem to the thermal storage liquid.

Methods, systems, and techniques for harnessing wind energy use a tethered airfoil and a digital hydraulic pump and motor, which may optionally be a combined pump/motor. During a traction phase, a wind powered airfoil is allowed to extend a tether and a portion of the wind energy harnessed through extension of the tether is stored prior to distributing the wind energy to an electrical service. During a retraction phase, the wind energy that is stored during the traction phase is used to retract the tether. The digital hydraulic pump and motor are mechanically coupled to the tether.

Methods, systems, and techniques for harnessing wind energy use a tethered airfoil and a digital hydraulic pump and motor, which may optionally be a combined pump/motor. During a traction phase, a wind powered airfoil is allowed to extend a tether and a portion of the wind energy harnessed through extension of the tether is stored prior to distributing the wind energy to an electrical service. During a retraction phase, the wind energy that is stored during the traction phase is used to retract the tether. The digital hydraulic pump and motor are mechanically coupled to the tether.

A turboexpander can operate as a microgrid electric generator for islanding operations. The turboexpander can recover energy lost during a pressure letdown sequence to generate electricity. Pressurized process gas can cause a turbine to rotate, thereby rotating a rotor within a stator of the turboexpander. A power electronics can include an islanding mode inverter to output an alternating current that comprises a frequency and an amplitude compatible with powering a load. The power electronics can include a battery that is charged by the turboexpander and can provide power for starting up the turboexpander. The power electrics can include a bidirectional inverter to send excess power from the turboexpander to a power grid and to receive power from the power grid for start-up.

A turboexpander can operate as a microgrid electric generator for islanding operations. The turboexpander can recover energy lost during a pressure letdown sequence to generate electricity. Pressurized process gas can cause a turbine to rotate, thereby rotating a rotor within a stator of the turboexpander. A power electronics can include an islanding mode inverter to output an alternating current that comprises a frequency and an amplitude compatible with powering a load. The power electronics can include a battery that is charged by the turboexpander and can provide power for starting up the turboexpander. The power electrics can include a bidirectional inverter to send excess power from the turboexpander to a power grid and to receive power from the power grid for start-up.