Zeolites are capable of adsorbing water vapor from an air stream and releasing heat in the process. Based on this principle, a mobile sorption heat storage system was developed. In a thermally insulated cylindrical steel container with a length of 7.5 m and a diameter of 2.5 m, 14,000 kg of zeolite (Köstrolith 13X) were accommodated in such a way that up to 12,000 m³/h of air can flow through it.