Echogen is a leader in the development of sCO2 power systems
PTES uses highly efficient and compact supercritical CO2-based power cycles. Echogen is a leader in the development of sCO2 power systems, with the only commercialized sCO2 power cycles in the world. The charge cycle is a heat pump using electricity to move and upgrade heat from a cold reservoir to a hot reservoir. The process is reversed with a heat engine, generating electricity from the thermal reservoir. The heat engine is based on Echogen’s commercial waste heat recovery technology. The cold reservoir is a variant of commercially available ice-on-coil cold storage systems.
A large coil is submerged in a water tank, and CO2 flows inside the coil melting or freezing water on the outside surface of the coil. The hot reservoir is sand stored in silos. The sand is moved with conveyors and elevators, and heated and cooled with a fluidized bed heat exchanger. The nature of Echogen’s design allows scaling hours of storage duration by simply adding additional sand and water. Existing PTES installations will be capable of adding storage duration for a low incremental cost. Operating at moderate temperatures and utilizing low cost thermal storage media, PTES offers a simple solution, with a high RTE and low cost.