Development of a Hybrid Collector for an Innovative Energy Supply System Using Molecular Solar Thermal Energy Storage
Abstract
An innovative system for chemical heat storage using photo-induced isomerization will be presented. For this process, also known as molecular solar thermal energy storage (MOST), a special collector was developed. The initial small collector was scaled up to hybrid collector of a size of 0.5 m². This collector consists of a transparent front part for the photo-induced isomerization, but this process does only absorb a small spectral part within the UV region of the solar energy spectrum. Therefore, the back part of the hybrid collector is similar to a conventional flat plate solar collector to absorb the remaining solar energy. The paper covers the special requirements for materials and geometries for an optimum and most efficient operation. The biggest challenge in the development at the first stage of the project was the necessity to use of a solvent as a carrier for the molecules with the photo-induced isomerization properties which was not compatible to any usual materials. Furthermore, the paper describes the upscaling process, the testing and the installation of the first complete full-scale prototype of the hybrid collector in a complete MOST system, consisting of the collector, pumps, storage tanks, heat release device and heat exchangers.