A power plant having a steam circuit which can be supplied, in the region of a heat recovery steam generator, with thermal energy for producing steam, the steam circuit has, in the region of the heat recovery steam generator, a high pressure part, a medium pressure part and a low pressure part. In addition, a heat reservoir which has a phase change material and which is not situated in the region of the heat recovery steam generator is included, wherein, in order to supply the heat reservoir with thermally processed water, a supply line which leads out from the high pressure part or the medium pressure part is included and a discharge line which leads into the medium pressure part, the low pressure part or a steam turbine is included for discharging thermally processed water from the heat reservoir.

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.

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.

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.

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.

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.

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.

An energy storage device having: a high-temperature regenerator containing a solid, particularly porous storage material (S); a working gas (A) as the heat transfer medium to transfer heat between the storage material (S) and the working gas (A) flowing through; and a charging circuit and a discharging circuit for the working gas (A). The charging circuit is designed such that starting from a pre-heating unit at least one first heat transfer duct of a recuperator, a first compressor (HO), the high-temperature regenerator, a second heat transfer duct of the recuperator and then a first expander are interconnected, thus forming a circuit, so as to conduct fluid. The first compressor is coupled with the first expander, and the first compressor forms part of a first piston machine (K1) and the first expander forms part of a second piston machine (K2), the piston machines (K1, K2) being operable either as a compressor or as an expander such that the first compressor of the charging circuit forms a second expander in the discharging circuit and that the first expander of the charging circuit forms a second compressor in the discharging circuit. The high-temperature regenerator can be connected to either the charging circuit or the discharging circuit to conduct fluid and can be controlled such that the high-temperature regenerator, the compressor and the expander form either part of the charging circuit or part of the discharging circuit. The charging circuit, the discharging circuit and the high-temperature regenerator have the same working gas (A) so that the working gas (A) comes into direct contact with the storage material of the high-temperature regenerator both in the charging circuit and in the discharging circuit.

The invention relates to a thermal power station and a method for storing heat by means of a steam generator a water-steam cycle which is connected to the steam generator and to a thermal store. Said thermal store comprises a first container for a heat store medium when it is cold, a second container for the heat store medium when it is hot, and a heat exchanger which is connected to the two containers and which is connected to the heat-steam cycle via a water-steam feed line and a water-steam discharge line. The thermal store has an additional heat exchanger which is connected to the two containers, an air feed line and an air discharge line being provided, the air discharge line being connected to the combustion air feed line leading to the combustion chamber.

The present disclosure provides pumped thermal energy storage systems that can be used to store and extract 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.