IEA SHC Task 58 – IEA Solar Heating and Cooling Task58 Material and Component Development for Thermal Energy Storage

The goal of the Task 58 is to support an application-oriented development of innovative and compact thermal energy storage materials: Phase Change Materials (PCM) and Thermochemical Materials (TCM). Therefore, experts from the fields of materials development, and thermal storage component development and system integration collaborated for three years to further develop materials and components for thermal energy storage. Work was done in 4 main fields: the definition of the proper boundary conditions for the development and integration of thermal energy storage technologies for different applications; the development and characterisation of novel thermal storage materials, the definition and testing of reliable testing procedures to determine the performance of materials and components; the analysis of design aspects for thermal energy storage components. The collaboration in the IEA Task58 between materials experts and application experts leads to improved understanding and therefore accelerates material and component development in the field of compact TES. Standards for sample preparation, measurement and for reporting are prerequisite for constructive discussions and rapidly addressing challenges and advancing TES technologies. A large number of relevant applications exists for compact thermal energy storage because of their high flexibility in design and operation. Standardized reference conditions can be defined for the building sector. For industrial applications however the diversity of processes makes it very difficult!

A number of innovative and improved materials were developed and continuously are being developed, tested and introduced in components. The developed characterization methods are the basis for material evaluation and comparison and are basis for the developed database input where the results are publicly available (https://www.thermalmaterials.org/) . The material properties cover not only the technical performance, but also questions like stability and compatibility.

The achievable charging/discharging power is strongly influenced by the component design, where the interaction of the storage material with the component is crucial. Therefore, the actual storage capacity and material stability in the application have to be tested under real conditions and requirements. When comparing systems, the identification of component parameters is necessary to enable the comparison of compact storage concepts.