Life cycle assessment of phase change materials, component and system concepts.

The main objectives of research on Phase Change Materials (PCM) for thermal storage are the development of low-loss and compact storage systems with high capacity (sensible water storages being the benchmark). If the storage is to be implemented in an application with the aim to increase its energy efficiency, beside the technical/thermal properties and cost factors, also the environmental impact of the storage production and operation need to be considered during development. Yet up to now, a holistic development approach that
considers the primary energy used for the manufacturing, operation and disposal in relationship to the potential energy savings does not exist for innovative storage concepts. Therefore, we are presenting data on the environmental impact of PCM on material and component level developed within the German project “Speicher LCA” (engl. “Storage Life Cycle Assessment”). The evaluation shows that PCM can be environmentally beneficial compared to water, if they are used in an application with a small useful temperature difference (e.g. cooling). A further analysis shows that in applications with high cycle numbers, PCM-based storages can also be favorable compared to an ice storage because of the higher Energy Efficiency Ratio (EER) of the chiller providing the cold (100 to 600 cycles, depending on the material).