The refrigeration system based on the conventional compression cycle consumes an enormous amount of high-grade energy. Using fossil fuels as the energy sources results in the addition of CO2 into the atmosphere and consequently stimulating higher greenhouse effect. The ejector refrigeration systems powered by renewable energy sources would be an effective alternative without increasing global CO2 footprint. In this study, the performance characteristics of a solar ejector refrigeration system working with R718 are analytically calculated by using a one-dimensional flow model. At the critical mode, the solar ejector-refrigeration system is analyzed at various working conditions such as condenser temperature, evaporator temperature, generator temperature, and ejector area ratio. The critical system performance is analyzed to meet any designated working conditions with a wide range of condenser temperatures. It is found that during the critical mode of operation, higher area ratio, higher evaporator temperature and lower generator temperature enhance the performance of the system. The minimum evaporator temperature, and the maximum generator temperature designed to acquire the required coefficient of performance value are also calculated.