THERMOELECTRIC ENERGY STORAGE SYSTEM HAVING AN INTERNAL HEAT EXCHANGER AND METHOD FOR STORING THERMOELECTRIC ENERGY

摘要

A thermoelectric energy storage system (TEES) and method for converting electrical energy into thermal energy to be stored and converted back to electrical energy with an improved round-trip efficiency are disclosed. The TEES comprises a working fluid circuit for circulating a working fluid through a first heat exchanger (18) and a second heat exchanger (20),a thermal storage medium circuit for circulating a thermal storage medium, the thermal storage medium circuit having at least one hot storage tank (24) coupled to a cold storage tank (22) via the first heat exchanger (18). The arrangement maximises the work performed by the cycle during charging and discharging for a given maximum pressure and maximum temperature of the working fluid. Advantageously, this maximises the round-trip efficiency of the system.