A solar-assisted ejector cooling system is simulated in order to investigate the validity of a design methodology. Hourly simulation results allow for Computing the solar fraction, in cases when the cooling capacity of the ejector cycle is kept constant during daily periods. The computed solar fraction is compared with estimates obtained from the f-(phi) over bar -chart method based on the utilizability concept. An equivalent minimum temperature for the utilizability of the solar system is found, which proves to be different, but close to, the vapor generator temperature of the ejector cycle. It is shown that the solar fraction derived from the utilizability concept based on the monthly means of the global solar radiation is applicable to solar-assisted ejector cooling cycles, in cases when the minimum temperature at which solar heat is supplied to the load is determined. Good agreement is found between the solar fraction results obtained from the simulations and those obtained by the f-(phi) over bar -method. (C) 2008 Elsevier Ltd. All rights reserved.