Preliminary prospects of a Carnot-battery based on a supercritical CO2 Brayton cycle

Abstract

As part of the change towards a higher deployment of renewable energy sources, which naturally deliver energy intermittently, the need for energy storage systems is increasing. For compensation of disturbance in power production due to inter-day to seasonal weather changes, long-term energy storage is required. In the spectrum of storage systems, one out of a few geographically independent possibilities is the storage of electricity in heat, so-called Carnot-Batteries. This paper presents a Pumped Thermal Energy Storage (PTES) system based on a recuperated supercritical CO2 Brayton cycle. The modelled system provides a round-trip efficiency of 38.9%.