A great concern in Concentrated Solar Power (CSP) is to boost energy harvesting systems, by finding materials with enhanced thermal performance. Phase Change Materials (PCM) have emerged as a promising option, due to their high thermal storage density compared to sensible storage materials currently used in CSP. A thermal storage system for solar power plants is proposed, a thermocline tank with PCM capsules together with filler materials, based on multi-layered solid-PCM (MLSPCM) thermocline-like storage tank concept [1,2]. A detailed selection of the most suitable high temperature PCM, their containment materials and encapsulation methods are shown. BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer review by the scientific conference committee of SolarPACES 2014 under responsibility of PSE AG 938 B. Muñoz-Sánchez et al. / Energy Procedia 69 ( 2015 ) 937 -946