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Recycled ceramics made of inertized asbestos containing wastes have been submitted to high pressure/temperature cycling tests in the operating range of ACAES and CSP applications. Ten successive cycles between room conditions and 610 °C/30 bars for a cumulated duration of 2500 h lead to a validation of the ability of the material to resist to those constrains. The Wollastonite/Augite initial structure is gradually transformed in a unique Augite containing material. While mechanical parameters and density are unchanged, thermal capacity is reduced by 5% and thermal conductivity increased by 30%. This last result offers an advantageous way to enhance the thermal conductivity of those recycled ceramics, a key parameter to control the charge/discharge power in TES systems. [ABSTRACT FROM AUTHOR]

Abstract: This work aims to evaluate the performance of a solar domestic hot water (SDHW) system including a latent storage material. The originality of our approach consists to place a composite made of compressed expanded natural graphite (CENG) and phase change material (PCM) directly inside a flat plate solar collector in order to replace the traditional copper-based solar absorber. According to this target, the study is composed of two steps: the composites preparation and characterization; and the analysis of the system to achieve optimal integration of the material in the process. The present paper is focused on the selection of the most promising composite to implement in the solar collector. In order to reach this objective, several composites based on CENG and various storage materials (paraffin, stearic acid, sodium acetate trihydrate and pentaglycerin) have been elaborated and characterized. The synthesis of all these measurements allowed us to select three composites whose characteristics match their integration into a solar thermal collector. [Copyright &y& Elsevier]

Abstract: Alternative low cost materials are evaluated through the valorization of by-products derived from mining and metallurgical industry for solid sensible heat based energy storage systems. They were used either as received or formulated as aggregates in mortars, and their thermal and mechanical properties were characterized. A selection methodology was applied in order to compare them with available materials found in the literature for applications as (STES) materials, and with materials from Cambridge Educational Software (CES) Selector database. It was demonstrated that these recycled materials have a high potential for these thermal energy storage applications. [Copyright &y& Elsevier]

Abstract: The overall objective of this work is to evaluate the potential of compressed expanded natural graphite (CENG) and phase change material (PCM) composites to improve the performance of solar domestic hot water (SDHW) systems. To achieve this target, an original approach has been chosen. Comparatively to other studies, in which the storage material is usually placed on top of the water tank, the proposed approach was to place the composite directly inside a flat plate solar collector in substitution to the traditional copper-based solar absorber. In a previous paper (), elaboration and characterization of various composites led to the selection of three relevant composites suitable to their integration into a solar thermal collector. The present paper is devoted to the analysis of such a system to evaluate its actual performance. To reach this objective, a numerical model is proposed and its reliability validated by mean of corresponding experimental data. Despite the fact that under summer meteorological conditions the performed simulation highlights an increase of the system efficiency by adding a composite to the solar collector, the cumulative annual performance of such a system is penalized by low efficiency during winter time. However, the obtained simulated results allow us to offer a perspective of work that would maximize the benefits of adding storage composite to a SDHW system. [Copyright &y& Elsevier]