## 2 Sensible Heat Storage (SHS) Method  
Sensible heat storage (SHS) is the most traditional, mature and widely applied TES solution due to its simple operation and reasonable cost. However, it suffers from the low-energy storage density achieved compared to the other two TES options, viz LHS and TCHS [27]. In this approach, the energy transfer (_as heat_) to and from the storage medium that can be liquid (_water_, _oil_, etc.) or solid (_sand_, _rock beds_, _brick_, etc.) results in the corresponding change (_increase or decrease_) of the medium's temperature. Figure 4 depicts the SHS typical diagram during sensible heating or cooling with no phase transition during the process [3,28]. One of the advantages of this mode is that the storage and release of the accumulated heat (_charging and discharging cycles_) can be repeated without any problem while involving a large volume to meet the needs [29]. In addition, this method generally takes the advantage of certain properties of the storage material such as its high specific heat [30]. Since the quantity of sensible heat stored (\(Q\)) depends on the mass (\(m\)), the heat capacity (\(C_{p}\)) [30], two main characteristics of SHS materials (SHSMs) should be pursued to increase the capacity storage volume (M)\(\cdot\)m\({}^{-3}\)) with high specific heat and density. Among the abundantly available materials, water has a comparably high specific heat and density, wherefore it is quite frequently used as a storage material in many practical applications. For example, the sensible heat storage capacity has been estimated at 250 MJ\(\cdot\)m\({}^{-3}\) for a thermal gradient of 60 \({}^{\circ}\)C in the case of water [18]. [PERSON] et al. [31] presented a bar chart where a certain property (e.g., _specific heat capacity_) is plotted for all families of engineering materials mostly used in SHSMs to better  
Figure 3: Keywords’ co-occurrence for the storage sector [26], reprinted/adapted with permission from Ref. [26], 2022, Elsevier. identify and classify them. On the other hand, thermal conductivity, thermal diffusivity and flow rate play a key role in charging/discharging cycles that ensure stratification ability. It is worth noting that a high thermal stratification facilitates the release of heat, allowing a transfer of thermal energy at low temperature toward the colder zones during the charging period, and thereby, a higher exergy (_quality energy_) which is promptly obtained from the hottest zones during the discharge process [32]. The thermal effusivity parameter appears as the main variable influencing thermal inertia in passive construction applications [33]. This parameter characterizes the rate at which a material can release or absorb heat, where its raise augments the heat stored quantity and thereby mitigates energy consumption [18]. In addition, the availability, cost, toxicity and volume change are further criteria for the selection of sustainable SHSMs [18]. As mentioned before, the main disadvantages are their limited energy density and the device self-discharge [34]. To assess the SHS system performance, [PERSON] et al. [35] pointed out that the relevant quantities are energy storage capacity, power, efficiency, time of charging/discharging cycles and cost. According to [PERSON] et al. [26], the SHS approach has been widely used in solar applications such as concentrated solar power plants (CSP) [36] or desalination [37]. For example, the water-based SHS is one of the most widely used solar TES systems in residential applications (_see sketch in_ Figure 5) [3], and besides, [PERSON] et al. [38] have published a comprehensive review article on SHS systems and materials available and applied in industrial solar heat applications. According to the temperature range, they pointed out that there are mainly three groups of solar industrial processes, viz low-temperature (<150 \({}^{\circ}\)C), medium-temperature (150 \({}^{\circ}\)C \(<\)\(T\) < 400 \({}^{\circ}\)C) and high-temperature (>400 \({}^{\circ}\)C) applications.