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In most of the developed nation, the increase in percentage share of renewable power in the total power generation causes major concerns over the integration of these renewable power with the grid resulting grid instability. Energy storage is a new frontier technology which is considered as the ultimate solution in developing micro smart grid with distributed renewable power generation. Most of the hot countries like India spend nearly 24% of the electricity generated on air conditioning and food preservation. Under such scenario, among the various types of storage systems, the cool thermal storage plays a viral role to promote renewable power in an economical way. Considering the importance in the present renewable energy scenario, in the present work, an experimental investigation was performed on a packed bed cool storage system integrated with a chiller system which has major advantages in central air conditioning system for demand management strategies.The storage system consists of encapsulated spherical balls filled with a mixture of distilled water and pseudomonas (nucleating agent) as phase change material and a mixture of distilled water and Mono-ethylene glycol as heat transfer fluid. The essential parameters such as reduction in subcooling, instantaneous and cumulative heat transfer during the charging process are presented for the efficient operation.

In most developed and developing nations, nearly 40% of the energy generated is utilized in the building sector, in which nearly 50% of the energy is consumed by building cooling/heating systems. However, the energy requirement for building cooling/heating varies continuously with respect to time. Hence, in hot countries, if the cooling system is integrated with a storage system, the cooling system need not be designed for the peak load requirement. Further, this kind of storage system is very useful and economically beneficial in the scenario of dynamic electricity tariff, being introduced in many countries in the emerging renewable energy scenario to solve the grid stability issues. Further, it is very useful to promote microgrid with distributed renewable power generation. Considering the above, the major objective of the present research is to demonstrate the integration of the air-conditioning system with a sensible heat storage unit for residential applications. An experimental setup is constructed, and experiments were conducted to evaluate the heat exchange behavior during the charging and discharging process by varying the inlet temperature and the mass flow rate of the heat exchange fluid through the circuit. It is observed that the set temperature of the cool storage tank is to be maintained above +5°C to achieve better efficiency during the charging process. During the discharging process, the room could be maintained at the required comfort condition for a duration of 285 min with 29 cycles of operations between the set point temperature limits of 25°C to 28°C. When the inlet brine temperature of the cooling unit reached 20°C, in the next cycle, bringing down the room temperature again to 25°C could not be achieved. The results shown in this work are beneficial for efficiently operating the cooling system and useful in promoting renewable energy in the near future in the building sector. Also, the low-temperature sensible heat storage system is capable of maintaining the storage temperature at approximately +4°C, instead of -4°C normally employed in the case of latent heat-based storage system that allows higher performance in the sensible heat storage system.