Sorption systems for thermal energy storage

Sorption thermal energy storage (STES) systems exploit reversible sorption and desorption processes to store thermal energy as potential energy between a sorbate (e.g., water, ammonia, alcohols) and a sorbent (e.g., salt solutions, salt hydrates, solid sorbents). This technology belongs to the wider family of thermo-chemical reactions and is specifically suited for low and medium charging temperatures (i.e., below 200°C). In this chapter, the working principle of different STES configurations is discussed. Furthermore, experimental methodologies to evaluate the expected efficiency of the working pairs are described. Finally, some examples of lab-scale reactors recently developed and tested are described to present the current state of the technology development.