Compact thermal energy storage (CTES) technologies are the subject of Task 40. These technologies are based on phase change materials (PCM) and thermochemical materials (TCM). Materials from these classes will be studied, improved, characterized, and tested in components. The main components for these technologies are heat exchangers and reactors, and these are also studied and further improved in the Task.
Objectives and Subtasks
The main objectives of Task 40 are to have a better understanding of the factors that influence the storage density and the performance degradation of CTES materials, to be able to characterize these materials in a reliable and reproducible manner, to have methods to effectively determine the state of charge of a CTES, and to have better knowledge on how to design optimized heat exchangers and reactors for CTES technologies.
To achieve these objectives, the work is organized into five Subtasks:
Subtask A: Material Characterization and Database
Subtask B: CTES Material Improvement
Subtask C: State of Charge – SoC Determination
Subtask D: Stability of PCM and TCM
Subtask E: Effective Component Performance with Innovative Materials
Follow-up of Annex 33
Task 40 is a follow-up of Annex 33, that included the characterization of new CTES materials concerning their properties, the creation of a database as well as developing testing procedures in the lab and under reference application conditions. These conditions were discussed for energy relevant applications. Further focus was laid on the interaction between the storage material and the storage component, and mainly with the heat and mass transfer performed in the component or reactor. Thereby, first results towards a reliable power and energy density were deduced. As Annex 33, Task 40 is a collaboration between the Solar Heating and Cooling TCP (IEA SHC Task 67) and the Energy Storage TCP.