The global urgency to face climate change has stressed the development of sustainable energy technologies aimed at reducing greenhouse gas emissions. In this contest, heat pump systems (HPs) represent a fundamental technology for decarbonizing the industrial and residential sector by offering an efficient alternative to traditional fossil-fuel-based heating systems. This master thesis investigates the development and experimental analysis of an innovative micro-heat pump prototype that utilizes Propane (R290) as a natural refrigerant; a choice characterized by a near-zero environmental impact (GWP = 0.02) [3] and a high latent heat of vaporization, making it a sustainable alternative to traditional synthetic refrigerants. The core innovation of this system lies in its integration with a thermal energy storage (TES) unit based on Phase Change Materials (PCM).