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Solar jet refrigeration. The schematic diagram of a solar jet refrigeration system is shown in Figure 3. This system features a simple structure, stable operation, and good reliability, but it has a low COP value. As a result, there has been a trend to use electrical energy to assist in increasing the impingement pressure of the ejector in order to improve system performance. A solar-enhanced jet refrigeration system uses hot water at high temperature obtained from solar collectors as a heat source, along with a low-boiling-point working fluid and a mechanical compression jet refrigeration cycle. This system primarily improves the performance of the ejector by increasing the pressure of the induced flow; it combines the advantages of mechanical compression refrigeration cycles with those of steam injection refrigeration cycles, offering high thermal efficiency, with a COP that is 50% higher than that of conventional jet refrigeration systems. Solar semiconductor cooling technology: A solar semiconductor cooling system makes use of the thermoelectric cooling effect of semiconductors; the necessary direct current is supplied by solar cells, thereby achieving cooling or heating effects. This technology is also known as thermoelectric cooling or Peltier cooling. Solar cooling offers excellent seasonal suitability. In summer, the hotter the weather, the greater the load on air conditioners and the more cooling capacity is required; at the same time, solar radiation is at its strongest, providing the most heat energy, and thus solar air conditioners can deliver the highest level of cooling. In winter, solar radiation decreases, but the temperature of the water required for heating cycles is not high. With a collection area sufficient to meet the cooling requirements, it is still possible to satisfy the heating demands. This characteristic has led to increased attention and development of solar cooling technology. There are various ways to achieve solar-powered cooling, such as “light-heat-cooling”, “light-electricity-cooling”, and “light-heat-electricity-cooling”. A solar semiconductor refrigeration system consists of components such as a solar photovoltaic converter, a digital control matcher, an energy storage device, and a semiconductor refrigeration unit. Solar photovoltaic converters produce direct current, of which a portion is supplied directly to semiconductor cooling devices, while the other portion is stored in energy storage devices for use on cloudy days or at night, ensuring that the system can operate properly around the clock. Currently, as the prices of solar cells and thermoelectric materials continue to decline and power generation efficiency improves rapidly, the cost of solar semiconductor cooling systems is also dropping significantly. More optimistically, their performance has also seen notable improvements, which to some extent promotes the widespread use of solar semiconductor cooling systems. Based on this trend, it can be inferred that various clean and low-noise solar cooling systems will all be realized in the near future.