In the context of smart grid development, energy flexibility is a critical factor for optimizing the integration of renewable energy sources and improving overall energy efficiency. This study focuses on the energy flexibility analysis of a simulated hotel and a supermarket refrigeration system. The main objective is to evaluate the potential for energy flexibility within the hotel building, that would enable it to dynamically interact with the smart grid by adjusting its energy consumption based on supply conditions and demand response strategies. The hotel building was modelled with Type 56, which provides comprehensive capabilities for simulating thermal zones, including heat gains, losses, and thermal storage effects. The building model was then coupled with a PV system, designed to meet part of the hotel’s electricity demand. Additionally, the model included a supermarket equipped with a CO2 refrigeration system with heat recovery capabilities, here implemented to produce domestic hot water for the hotel. The study analyzed several scenarios to assess the hotel’s energy flexibility potential. These scenarios included varying levels of PV generation, different DHW storage sizes, and the implementation of demand response measures.