Comparative life cycle assessment of thermal energy storage systems for solar power plants

Abstract

The present work compares the environmental impact of three different thermal energy storage (TES) systems for solar power plants. A Life Cycle Assessment (LCA) for these systems is developed: sensible heat storage both in solid (high temperature concrete) and liquid (molten salts) thermal storage media, and latent heat storage which uses phase change material (PCM). The aim of this paper is to analyze if the energy savings related to the stored energy of the different systems are enough to balance the environmental impact produced during the manufacturing and operation phase of each storage system. Some hypothetical scenarios are studied using LCA methodology to point out the differences between each TES system. The system based on solid media, due to his simplicity, shows the lowest environmental impact per kWh stored of all three systems compared. In addition, the liquid media (molten salts) shows the highest impact per kWh stored because it needs more material and complex equipment.

The work was partially funded by the Spanish government (projects ENE2008-06687-C02-01/CON, CTQ2009-14420-C02, DPI2008-04099I, A/023551/09, and ENE2011-22722). Antoni Gil would like to thank the Col·legi d’Enginyers Industrials de Catalunya for his research appointment. The authors would like to thank the Catalan Government for the quality accreditation given to their research group (2009 SGR 534). Eduard Oró would like to thank the University of Lleida for his research fellowship.