Malta Inc.

X Development LLC

Leland Stanford Junior University

Riken Corporation

Robert B Laughlin

Philippe Larochelle

Nicholas Cizek

Yoshinori Tokura

Zhixun Shen

Kentaro Ueda

Yue Ma

Yongtao Cui

Jun Fujioka

Efficient energy storage is provided by using a working fluid flowing in a closed cycle including a ganged compressor and turbine, and capable of efficient heat exchange with heat storage fluids on a hot side of the system and on a cold side of the system. This system can operate as a heat engine by transferring heat from the hot side to the cold side to mechanically drive the turbine. The system can also operate as a refrigerator by mechanically driving the compressor to transfer heat from the cold side to the hot side. Heat exchange between the working fluid of the system and the heat storage fluids occurs in counter-flow heat exchangers. In a preferred approach, molten salt is the hot side heat storage fluid and water is the cold side heat storage fluid.

Adiabatic salt energy storage

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.

Pumped thermal storage cycles with turbomachine speed control

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 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 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. Systems of the present disclosure can employ solar heating for improved storage efficiency.

Pumped thermal storage cycles with working fluid management

Pumped thermal storage cycles with recuperation

In the present disclosure, an example method is provided. The example method may comprise operating a pumped thermal system in a charging cycle at a first compression ratio, wherein the pumped thermal system comprises a working fluid circulating through, in sequence, a compressor system, a hot side heat exchanger, a turbine system, and a cold side heat exchanger, wherein the working fluid is in thermal contact with a hot thermal storage ('HTS') medium in the hot side heat exchanger and the working fluid is in thermal contact with a cold thermal storage ('CTS') medium in the cold side heat exchanger. The example method may also comprise operating the pumped thermal system in a discharging cycle at a second compression ratio different than the first compression ratio.

Varying compression ratios in energy storage and retrieval systems

Methods of hot and cold side charging in thermal energy storage systems

An example method may comprise providing a composite pumped thermal system having a plurality of subunits, each configured for operation in a thermal storage mode and a power generation mode; operating the system in power output mode with a power output level at an intermediate output level between 0% and 100% of a maximum output level of the system; reducing the power output level to 0% of the maximum output level by reducing a power output of a first subunit operating in a power generation mode; and at 0% of the maximum output level, wherein a power input level of the system is also at 0% of a maximum input level of the system, increasing the power input level to an intermediate input level between 0% and 100% of the maximum input level by increasing a power input of a second subunit operating in a thermal storage mode.

Pumped thermal and energy storage system units with pumped thermal system and energy storage system subunits

In an example, a system configured to operate in a heat pump mode and heat engine mode is disclosed. The system may comprise a first working fluid path, first hot thermal storage (HTS) fluid path, and first cold thermal storage (CTS) fluid path for operation in the heat pump mode. The first working fluid path may be configured to circulate the working fluid through, in sequence, a first compressor, first hot side heat exchanger, first turbine, first cold side heat exchanger, and back to the first compressor. The system may also comprise a second working fluid path, second HTS fluid path, and second CTS fluid path for operation in the heat engine mode. The second working fluid path may be configured to circulate the working fluid through, in sequence, a second compressor, second hot side heat exchanger, second turbine, second cold side heat exchanger, and back to the second compressor.

Pumped thermal systems with dedicated compressor/turbine pairs

Pumped thermal systems with variable stator pressure ratio control

Hybrid pumped thermal systems

Control of electrical conductivity is provided via electrically conductive magnetic domain walls between magnetic domains. The magnetic domains are identical except for their magnetic configuration. Altering a configuration of the magnetic domains (e.g., by thermal treatment, application of a magnetic field, etc.) can alter the electrical resistance of a device. Such devices can be used as non-volatile information storage devices or as sensors.

Growing community of inventors

Mountain View, CA, United States of America

Robert B Laughlin