Summary of Research on Pumped Thermal Energy Storage Technology

Pumped thermal energy storage (PTES) is a geographically unconstrained, system-friendly and long-duration energy storage technology based on thermal cycling and heat storage. Firstly, the technical principle was summarized, and the overall technical division was carried out according to different types of heat pump cycles. Secondly, the technical classification was refined based on different cycle working fluids, and the thermodynamic principles of each case were described in detail from the point of view of improving the round-trip efficiency of the system. Finally, the present situation of development was summarized and the future development was prospected. Results show that PTES achieves improved round-trip efficiency by compensating for irreversible losses in the thermal system through exergy appreciation. The round-trip efficiency of heat pumps using ambient temperature as a low-temperature heat source is mostly concentrated at 60%-75%. The coupling of external heat sources needs to meet the value of the application scenario, and the system round-trip efficiency is mostly concentrated at 70%-85%. The heat pump cycle is the most efficient electric-heating technology, with potential applications in areas such as safe peak shaving and high-quality steam supply in nuclear power, efficient peak shaving and rapid load increase in coal-fired power.