This deliverable introduces and describes two advanced simulation frameworks designed to model sorption ther- mal storage systems based on Sodium-hydroxide and water. Both models are based on physical equations and al- low insights into the systems’ behavior for diverse boundary conditions. The first model uses an integral approach to predict the steady-state working conditions of both the Absorber/Desorber-Unit and the Evaporator/Condenser unit. The second focuses on the detailed, time-dependent internal conditions of the Absorber/Desorber unit.