The achievable storage capacity of a sorption TES is depending on the available charging temperature and the required discharging temperature of the actual application. This relation can be calculated on the basis of the sorption equilibrium of the sorbent material. Figure 8 shows how the storage capacity depends on the temperature lift for different charging temperatures (TDes) in an open adsorption TES system [7 Dr AH]. The diagram shows curves for Zeolite and Silicagel. In addition to that the curve for the storage capacity of a hot water TES can be seen in figure 8.

It is obvious that higher charging temperatures are leading to higher storage capacities.

In a real application e. g. the heating system requires a minimum temperature. Below a certain temperature lift the thermal energy can not be used anymore. The values for the achievable storage capacity are strongly depending on the temperature lift. They are falling drastically, when higher Temperature lifts are needed. The curves of Zeolite and Silicagel intersect at a temperature lift of about 20 K. If a lower lift is sufficient Silicagel can reach higher values, if higher lifts are required Zeolite is delivers higher capacities.