IEA Task 42 Compact Thermal Energy Storage 2nd period

The project is the Danish contribution to the IEA SHC Programme Task 42 project "Compact Energy

storage: Material Development and System Integration, 2nd period".

A seasonal heat storage based on sodium acetate trihydrate with stable supercooling marketed by the

German company H.M. Heizkörper GmbH & Co. KG will be evaluated in terms of thermal performance and

economy by means of detailed experimental and theoretical investigations.

A seasonal heat storage based on a salt water mixture consisting of 58% sodium acetate and

42% water is currently being developed and evalueted by Technical University of Denmark, Graz University

of Technology, Nilan A/S and Velux A/S in the COMTES project supported by EU. This storage will be

compared to the German heat storage.

Calculations of the thermal performance of solar heating systems with the two above mentioned heat

stores will be carried out with validated simulation models for the two heat stores. The calculations will

show how the designs of the solar heating systems including the seasonal heat stores will influence the

size of the systems needed to fully cover the yearly heat demand of new buildings.

Based on the calculations and on evaluation of the economic conditions for the two heat stores the

optimum design and the suitability of the two heat stores will be elucidated.