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Over the past few years, the combination of solar power with refrigeration technology has matured, providing a promising solution for sustainable cooling. However, a key challenge remains, namely the inherent intermittency of solar energy. Due to its uneven temporal distribution, it is difficult to ensure continuous 24 h operation when relying solely on solar energy. To address this issue, thermal energy storage technology has emerged as a viable solution. This paper presents a comprehensive systematic review of phase-change material (PCM) applications in solar refrigeration systems. It systematically categorizes solar energy conversion methodologies and refrigeration system configurations while elucidating the fundamental operational principles of each solar refrigeration system. A detailed examination of system components is provided, encompassing photovoltaic panels, condensers, evaporators, solar collectors, absorbers, and generators. The analysis further investigates PCM integration strategies with these components, evaluating integration effectiveness and criteria for PCM selection. The critical physical parameters of PCMs are comparatively analyzed, including phase transition temperature, latent heat capacity, specific heat, density, and thermal conductivity. Through conducting a critical analysis of existing studies, this review comprehensively evaluates current research progress within PCM integration techniques, methodological classification frameworks, performance enhancement approaches, and system-level implementation within solar refrigeration systems. The investigation concludes by presenting strategic recommendations for future research priorities based on a comprehensive systematic evaluation of technological challenges and knowledge gaps within the domain.

Freeze-melting (F/M) desalination presents a sustainable and energy-efficient alternative to conventional desalination methods. In this study, we evaluated two solar-powered refrigeration systems, using BaCl2–NH3 and NH3–LiNO3 sorbent–refrigerant pairs, for seawater desalination and cooling applications. The NH3–LiNO3 system demonstrated a superior performance, achieving evaporator temperatures below −3 °C and producing up to 8 kg/day of ice. The system operated with a significantly lower energy consumption than the 3–6 kWh/m3 required by reverse osmosis (RO). Practical tests confirmed the dual functionality of the system, providing cooling for food preservation (maintaining 4 °C for 5 h) and climate control while producing desalinated water with total dissolved solids (TDS) levels of 3650 k/m3. Although the TDS remained above the WHO potable water standard, the output is suitable for irrigation and livestock watering. These results highlight the F/M desalination system’s potential to address water scarcity and cooling needs in resource-limited, off-grid regions, contributing to sustainable desalination technologies powered by renewable energy.

This article proposes an integrated solar PV refrigerator and heat pump (ISPVRHP) for Sub-Saharan African food vendors; the warm chamber would keep prepared food warm until the food is sold, while the cold chamber would minimise food spoilage. The ISPVRHP proposed in this article can cool water or other beverages and be capable of utilising the heat rejected to the atmosphere by the condenser for warming food. The ISPVRHP was modelled using ANSYS software, and the results were validated experimentally. The results show that both systems work well at peak hours, especially under more intense sun rays. The study found that the variation of incident solar radiation and ambient temperature has significant effects on the performance of the ISPVRHP; the wind speed, however, has only a minor impact on the total heat load of the system. In addition, the systems (cooling and heating) reached the desired temperatures and maintained them for long periods. The capacity of the refrigeration system can be increased by increasing the component sizes, including the PV system size. The ISPVRHP performance dropped substantially when the doors remained open for extended periods due to loss of energy through mass transfer.

This chapter contains sections titled: Introduction Multistage Refrigeration Cycles Cascade Refrigeration Systems Liquefaction of Gases Steam Jet Refrigeration Systems Thermoelectric Refrigeration Thermoacoustic Refrigeration Metal Hydride Refrigeration Systems Solar Refrigeration Magnetic Refrigeration Supermarket Refrigeration Concluding Remarks Nomenclature Study Problems References

This article presents novel research on the utilization of a neural-network-based time control system for microwave oven heating of food items within a solar-powered vending machine. The research aims to explore the control of heating time for various food products, considering multiple variables. The neural network controller is calibrated through extensive experimentation, allowing it to accurately predict optimal heating times based on input parameters such as food type, weight, initial temperature, water content, and desired doneness level. The results demonstrate that the neural-network-controlled microwave oven achieves precise and desirable heating durations, mitigating the risk of overheating and ensuring superior food quality and taste. Moreover, the solar-powered vending machine showcases a commitment to sustainable energy sources, effectively reducing dependence on non-renewable energy and minimizing greenhouse gas emissions. To maintain food quality and freshness, a food refrigeration unit is integrated into the vending machine, employing load-balancing technology to control the refrigeration chamber’s temperature effectively. Energy efficiency is prioritized in both the refrigeration unit and the microwave oven through intelligent algorithms and system optimization. The combination of a neural-network-controlled microwave oven, a solar-powered vending machine, and a food refrigeration unit introduces a novel and sustainable approach to food preparation and energy management.