Thermoelectric energy storage system with an intermediate storage tank and method for storing thermoelectric energy

摘要

A system and method for storing electric energy in the form of thermal energy is described. A thermoelectric energy storage system comprises a working fluid circuit for circulating a working fluid through a heat exchanger (16) and a thermal storage medium circuit for circulating a thermal storage medium, the thermal storage medium circuit having at least one hot storage tank (24), one intermediate temperature storage tank (22) and one cold storage tank (20) connected together via the heat exchanger (16). The flow rate of the thermal storage medium in the heat exchanger (16) is modified in order to minimize temperature difference between the working fluid and the thermal storage medium during charging and discharging cycles.