Annex 29

At the Executive Committee Meeting in Auckland, New Zealand, November 2012, this Annex was approved. The objective of this joint Task with the IEA Solar Heating & Cooling Implementing Agreement is to continue the activities started in Annex 24 “Compact Thermal Energy Storage: Material Development for System Integration”.
From the experience of the experts in the first period of the Task, it was concluded that one strong point elaborated is the interaction between the materials experts and the application experts, and the facilitation of this interaction by the division of the work into two subtasks: materials and applications.

The experiences of Annex 24 lead to a structure of the new Annex 29, with three materials working groups, one subtask for applications and one working group on economical evaluation of thermal energy storage (TES) systems. The economical evaluation will be performed by a bottom-up approach (while in Annex 24 a top-down approach was used). A questionnaire was sent out to predict the expected cost of each storage system, including material and other components. Within the material oriented working groups, novel storage materials – phase change materials or working pairs for thermo-chemical reactions – will be developed, tested and characterized. Finally they should be described by multi-scale simulation models in order to predict their performance under the operation conditions given by the application subtask. This subtask is responsible to define reference conditions for relevant application field for TES. Next Experts Meeting and Workshop will be held in Lyon, France, on April 28-30 2014. More information can be found at