Desert sand samples were thermally analyzed and their suitability for use as sensible heat thermal energy storage (TES) media is evaluated. Mass loss during heating was monitored with a thermal gravimetric analyzer (TGA) linked to a Fourier transform infrared spectrometer (FTIR). This technique showed that the relative mass loss rate of all the samples is comparable and that carbon dioxide is produced during their degradation. The calcite content of each sample is estimated assuming full calcination during the process. Additionally, larger fractions of the samples were heated in a high temperature electric furnace. This experiment showed that some samples tend to agglomerate at high temperatures, thus rendering their use as heat transfer fluid media questionable. Furthermore, color change from lighter tones to whiter tones is observed. This effect may impact the radiative properties of the samples, especially their solar absorptivity values. Finally, the average heat capacity in the 150-1100°C temperature range was measured with a differential scanning calorimeter. The average heat capacity for all the samples was 926.1J kg-1 K-1

An innovative gravity-fed combined solar receiver/storage system for thermal energy storage (TES) is presented for concentrated solar power (CSP) plants with beam down tower configuration. Sand particles are employed as heat collector, heat transfer and thermal energy storage media in contrast to conventionally used materials such as molten salts or synthetic oils. Relevant properties of two sand samples from the United Arab Emirates (UAE) deserts are examined. A prototype of the receiver was manufactured and its elements were characterized. Preliminary tests on the prototype were performed under the concentrated flux of a 2kW solar furnace and associated results are presented

Desert sand from the United Arab Emirates (UAE) is considered as a possible sensible heat, thermal energy storage (TES) material. Its thermal stability, specific heat capacity and tendency to agglomerate are studied at high temperatures. The analyses show that it is possible to use desert sand as a TES material up to 800-1000 °C. Above 800 °C, weak agglomeration effects start to become significant. The samples become solid above 1000 °C. This may represent a major operating limit depending on the handling mechanism in place for the possible transport of the sand. The sand chemical composition is analyzed with the XRF and XRD techniques, which reveal the dominance of quartz and carbonates. Finally, the spectral absorptivity of the samples is measured before and after a thermal cycle, as it may be possible to use the desert sand not only as a TES material but also as a direct solar absorber.