According to some aspects of the invention a heat pump includes first and second heat extraction units to extract heat from first and second heat sources in first and second temperature ranges, respectively, where the second temperature range is, on average, higher than the first temperature range. A fluid via defines a pathway through which the working fluid flows serially from the first heat extraction unit to the second heat extraction unit to the thermal storage unit. A pressure reduction stage is coupled to the via and serially disposed on the fluid circuit between the thermal store and the first heat extraction unit. In addition, either a compressor or a recuperator (or both) are coupled to the via and disposed on the fluid circuit between the first heat extraction unit and the second heat extraction unit.

Thermal management systems for cooling high-power, low-duty-cycle thermal loads that include at least three thermally coupled, closed subsystems are provided. Thermal management systems provided herein include a main thermal energy storage loop including a cold-temperature tank and a warm-temperature tank. Thermal management systems provided herein also include a multi-stage compression system or a cascaded architecture of a low-temperature vapor compression system and a high-temperature vapor compression system. Methods of transferring heat from one or more thermal loads to an ambient environment are also provided.

Thermal management systems for cooling high-power, low-duty-cycle thermal loads that include at least three thermally coupled, closed subsystems are provided. Thermal management systems provided herein include a main thermal energy storage loop including a cold-temperature tank and a warm-temperature tank. Thermal management systems provided herein also include a multi-stage compression system or a cascaded architecture of a low-temperature vapor compression system and a high-temperature vapor compression system. Methods of transferring heat from one or more thermal loads to an ambient environment are also provided.

A power generation system comprising a shared hot side thermal store, a shared cold side thermal store, a plurality of power subunits, and an electrical bus is disclosed. Each of the power subunits may connected or isolated from the shared hot side thermal store and/or the shared cold side thermal store.

A power generation system comprising a shared hot side thermal store, a shared cold side thermal store, a plurality of power subunits, and an electrical bus is disclosed. Each of the power subunits may connected or isolated from the shared hot side thermal store and/or the shared cold side thermal store.

The invention relates generally to methods and apparatus for start-up and control of liquid salt energy storage combined cycle systems.

The present disclosure provides pumped thermal energy storage systems that can be used to store electrical energy. A pumped thermal energy storage system of the present disclosure can store energy by operating as a heat pump or refrigerator, whereby network input can be used to transfer heat from the cold side to the hot side. A working fluid of the system is capable of efficient heat exchange with heat storage fluids on a hot side of the system and on a cold side of the system. The system can extract energy by operating as a heat engine transferring heat from the hot side to the cold side, which can result in network output. Systems of the present disclosure can employ solar heating for improved storage efficiency.

The present disclosure provides pumped thermal energy storage systems that can be used to store electrical energy. A pumped thermal energy storage system of the present disclosure can store energy by operating as a heat pump or refrigerator, whereby network input can be used to transfer heat from the cold side to the hot side. A working fluid of the system is capable of efficient heat exchange with heat storage fluids on a hot side of the system and on a cold side of the system. The system can extract energy by operating as a heat engine transferring heat from the hot side to the cold side, which can result in network output. Systems of the present disclosure can employ solar heating for improved storage efficiency.

The present disclosure provides pumped heat energy storage systems that can be used to store and extract electrical energy. A pumped heat energy storage system of the present disclosure can store energy by operating as a heat pump, whereby net work input can be used to transfer heat from the cold side to the hot side. A working fluid of the system is capable of efficient heat exchange with heat storage fluids on a hot side of the system and on a cold side of the system. The system can also extract energy by operating as a heat engine transferring heat from the hot side to the cold side, which can result in net work output. Shared powertrains and reversible powertrains are disclosed to circulate the working fluid.

The present disclosure provides pumped heat energy storage systems that can be used to store and extract electrical energy. A pumped heat energy storage system of the present disclosure can store energy by operating as a heat pump, whereby net work input can be used to transfer heat from the cold side to the hot side. A working fluid of the system is capable of efficient heat exchange with heat storage fluids on a hot side of the system and on a cold side of the system. The system can also extract energy by operating as a heat engine transferring heat from the hot side to the cold side, which can result in net work output. Shared powertrains and reversible powertrains are disclosed to circulate the working fluid.