In this paper, the mechanical and thermal properties of a sand-clay ceramicwith additives coal bottom ash (CBA) waste from incinerator coal power plantare investigated to develop an alternative material for thermal energy storage(TES). Ceramic balls are developed at 1000 ̊C and 1060 ̊C using sintering orfiring method. The obtained ceramics were compressed with a compressionmachine and thermally analyse using Decagon devise KD2 Pro thermal ana-lyser. A muffle furnace was also used for thermal cycling at 610 ̊C. It wasfound that the CBA increased the porosity, which resulted in the increase ofthe axial tensile strength reaching 3.5 MPa for sand-clay and ash ceramic. Theceramic balls with the required tensile strength for TES were selected. Theirvolumetric heat capacity, and thermal conductivity range respectively from2.4075 MJ·m−3· ̊C−1 to 3.426 MJ·m−3· ̊C−1 and their thermal conductivity from0.331 Wm−1·K−1, to 1.014 Wm−1·K−1 depending on sand origin, size and firingtemperature. The selected formulas have good thermal stability because themost fragile specimens after 60 thermal cycles did not present any cracks.These properties allow envisioning the use of the ceramic balls developed asfiller material for thermocline thermal energy storage (structured beds) inConcentrating Solar Power plants. And for other applications like solar cook-er and solar dryer

Ceramic Ball, Sand, Clay, Coal Bottom Ash, Thermal Energy StorageMaterial, Thermocline