The commencement of the EU F-Gas Regulation 517/2014 has brought significant impetus to the wide acceptance of transcritical CO2 systems as future-proof commercial refrigeration solutions across the world. In the present work, the HFC-free technologies which will become the norm in the next generation food retail stores are exhaustively described. Firstly, the most relevant properties of carbon dioxide as a refrigerant (R744) are summarized. At a later time, an overview on supermarket applications as well as on the EU F-Gas Regulation 517/2014 and its impact on the commercial refrigeration sector are presented. Also, the evolution of transcritical CO2 system layouts and the state-of-the-art CO2 technologies for food retail industry are discussed. Furthermore, some practical aspects as well as the potential energy advantages along with some relevant field/experimental measurements are brought to light. Finally, the results of various energy and environmental assessments in the European climate context in addition to the persistent challenges needing to be faced are revealed.