Powering the future: Releasing the potential of phase change materials in domestic refrigeration systems to store renewable energy
Abstract
• 2 billion home refrigeration units represent 4% of global electricity consumption. • This comprehensive review considers leveraging subzero PCMs for storing renewables. • Nanoparticles to boost PCMs’ properties of thermal conductivity and supercooling. • Rating domestic VCR units with PCMs needs uniform criteria to disclose potential. • Simplified numerical tools needed for virtual test benches and parametric studies. Globally, two billion domestic refrigeration systems (DRSs) represent 4 % of electricity consumption and stimulate Demand Side Management (DSM) actions like smart load shifting to balance energy supply and demand. Additionally, they offer the potential for Thermal Energy Storage (TES), which is crucial to revolutionizing thermal batteries for Renewable Energy Sources (RES). Explicitly, leveraging Phase Change Materials (PCMs) can also enhance the coefficient of performance (COP) and resilience to power outages in refrigerators/freezers. Despite extensive research, a comprehensive review addressing the barriers still hindering PCMs’ adoption in DRSs for storing renewables remains absent. This paper fills that gap by covering existent subzero cold storage PCMs, debating corrosion and leakage issues, and summarizing findings from experiments on DRSs with PCMs at the evaporators and compartments. It concludes by reviewing state-of-the-art numerical tools for system design, optimization, and control. Our findings highlight that novel PCMs have improved thermal conductivity and reduced supercooling but require further development toward long-term chemical stability. Experimental studies project up to fourfold autonomy extensions and 50 % reductions in energy consumption, operating costs, and emissions in PCM-enhanced DRSs. Literature reveals that systems with up to 2500 kJ of additional latent storage capacity have been investigated, primarily relying on exhaustive experimental/empirical studies. To advance this field, this review proposes future research directions to unleash the PCMs’ potential for accelerating DRSs’ transformation into advanced thermal batteries for renewable energy storage. Specifically, we advocate for developing simplified dynamic models to enable virtual test benches that support parametric studies and avoid complex CFD simulations.