Sand, being an abundant and eco-friendly material, has the potential to serve as a cost-effective alternative for thermal energy storage systems. In India, with its diverse geography and soils, it is essential to assess the heat-storing capacity of different soils for use in such systems. This study envisages the thermal energy storage capacity of sand, and is compared with clays having varying liquid limits. The cubic prototype comprises a stainless-steel solder pot consisting of lead embedded with the tungsten coil for heating of the sample within. A 25-mm-thick layer of glass wool has been provided for insulation. Mineral insulation sensors were connected to a 4-channel data logger to record the results. The results indicate that sand has the highest thermal inertia, while clay soil has a higher specific heat and volumetric heat capacity than sandy soil for the same moisture content and soil density. Additionally, the thermal diffusivity of the soils varies with moisture content and texture. This study focuses the heat storing capacity of sand and other types of expansive soils such as kaolinite montmorillonitic and montmorillonitic soils. Samples of sand and clay were subjected to different intensities of heat, and their storage properties were measured. The results show that black cotton soil with liquid limit of 74% has the highest heat retentivity among the three types of soil and sand samples tested, whereas black cotton soil having liquid limit of 66% has heat retentivity almost equal to that of the sand sample having specific gravity being same as that of the soil (G = 2.71).