Environmental and economic life cycle assessment of thermal energy storage based on organic phase change material embedded in open-cell copper foams

Abstract

This study deals with an economic and environmental Life Cycle Assessment of an innovative thermal energy storage - based on phase change materials embedded in open-cell copper foams - coupled with a solar heating and cooling residential system located in Italy. The results are compared with a traditional water-based storage with the same energy storing capacity. For both systems, an auxiliary gas-fired boiler is considered to integrate the renewable energy, in order to satisfy the building heating and cooling needs. Compared to the traditional system, the innovative storage guaranteed a lower natural gas consumption, 428 m3/y respect to 525 m3/y, due to better energy utilization obtained with a constant heat release/accumulation temperature during the solidification/melting phase of the paraffin. This reduction compensates the greater impact due to the consumption of raw materials and energy during the assembly phase of the innovative storage, and determine an abatement of the environmental impact over the 20 years of operation of about 14.6%, i.e. 1517 pt against 1777 pt in terms of global impact indicator. On the other hand, the innovative system proposed appears to be still expensive if compared to the conventional water-based storage, with an estimated annual cost of € 1,240 against € 696.