A Compressed Heat Energy Storage (CHEST) system, which is a specific variant of Pumped Thermal Energy Storage systems (PTES) based on the Rankine cycle, is under development in the H2020 CHESTER project. The developed CHEST system consists of a high temperature heat pump, a high-temperature thermal energy storage system combining both latent and sensible heat storages, and an organic Rankine cycle system.

Each subsystem has been experimentally tested individually, and their combination comprises a laboratory-scale prototype that is used to experimentally validate the behaviour of a CHEST system integrated in a Smart DH and other electrical markets.