> The sand used in the thermal energy storage (TES) system could be heated to the range of 1,100 C using low-cost renewable power. [...] when electricity is needed, the system will feed hot sand by gravity into a heat exchanger, which heats a working fluid, which drives a combined-cycle generator. So this is definitely not a "bury your heating coils in a sand dune, then connect..." technology. Quartz melts (per Wikip…
Sand-sourcing issues are typically related to types of sand required for special applications, such as in concrete or silicon wafer production that needs very specific types or shapes of the grains. This kind of application would probably work with “regular” sand that’s unsuitable for those special purposes, and also happens to be the most common type of sand.