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.