CaCO3 based thermal energy storage system is a promising technology for high temperature solar thermal applications. However, this technology is not mature yet, thus it needs more attention. More importantly, the challenges encountered during the reactor design as well as the integration of these systems with solar power plants are the technological concerns, hampering the large-scale industrial applications. The objective of the present study is to provide a thorough outlook of CaCO3/CaO systems, the kinetics of the calcination and carbonation reactions, the cyclic stability as well as its related problems and the solutions. Various techniques dealing with CO2 storage (i.e., produced because of decarbonation of CaCO3) are discussed in detail. At the end, the main challenges corresponding to the CaCO3 based thermochemical system have been elaborated together with the brief guidelines, helping the researchers to address the raised issues more comprehensively.