New Solar Thermal Storage Concept – Combined Hot Water and Sorption Store
Abstract
A new concept for solar thermal energy storage combining a conventional hot water store with a sorption store is being developed and investigated at the Institute of Thermodynamics and Thermal Engineering (ITW), University of Stuttgart. The particular advantages of the two storage technologies – sensible heat and sorption – complement one another optimally. The hot water store is used as shortterm store providing a high heat supply rate. The sorption store enables long-term storage almost without any losses. For this application long-term means several days or weeks. The combined hot water and sorption store intends to improve the performance and efficiency of a solar thermal system for domestic hot water preparation (DHW) and ensure heat supply entirely on a solar basis during the summer period. The fundamental adsorption and desorption behaviour has been determined by experiments on a sorption store in laboratory scale with a volume of about 4 litre. A full-scale prototype store, consisting of a sorption store with a volume of 100 litre inside a DHW store, is being constructed and will be monitored in laboratory.