Thermocline Thermal Energy Storage is a newly developed technology to increase the commercialization of solar thermal energy in residential and industrial sectors. The primary element of energy storage is filler material, which stores/releases energy during the charging/discharging process. More than 1,30,000 commercial materials are available as filler materials. The thermo-physical properties such as density, thermal conductivity, specific heat, and latent heat play a crucial role in energy storage (e.g. High thermal conductivity provides both merit and demerit for the system). So, it is essential to trade off all properties along with cost. The cost of the material is different with location; it is a challenging task to choose the superior filler material for energy storage. The new methodology has been developed and proposed for both sensible and phase change material selection, and it is experimentally validated. However, the charging/discharging characteristics are mainly on the energy interaction between heat transfer fluid and filler material. The thermocline is a transition layer between higher and lower temperatures, which stores the energy in the storage system. The thermocline characteristics are essential to developing the energy storage system for commercialization. The characteristics are evaluated with the effect of filler material temperature, filler material diameter, the diameter of the storage tank, and height of the tank, which are studied with the stability of thermocline from a wide range of Reynolds numbers 1 to 3000. As well, the parametric and sensitivity studies were carried out, found that the most influential non-dimensional parameters, such as Stanton number (St), porosity (Ɛ), and Diameter (D/r), for energy storage, which were used for future optimization to increase the commercialization further.
In the commercialization aspect, the thermo-economic-environmental investigation was carried out for solar residential combined power and potable water production integration with thermocline thermal energy storage system and found a 23.91% improvement in energetic performance. In the industrial sector, a thermo-economic-environmental investigation was conducted for solar combined power and ground-wall tile production with a thermocline thermal energy storage system found 41.16% and 6.36% better energetic and exergetic efficiency than conventional system.