The linear Fresnel collector technology is currently being commercialized by several companies for the application in solar thermal power plants and it appears as a technology with very high potential to reduce costs. The present paper compares the annual behavior in terms of annual electricity output, levelized cost of energy (LCOE), and capacity factor (CF) of 50-MW direct steam generation (DSG) linear Fresnel power plants with different solar field sizes and different backup system capacities. A sensitivity analysis of site's parameters (direct normal irradiation (DNI), altitude, average temperature, etc.) has been added by the choice of different locations on the south of Algeria (Hassi R'mel, Tamanrasset, and InSalah) to provide a comprehensive analysis. For this purpose, System Advisor Model (SAM) software has been used. As follows from the results, a DSG linear Fresnel solar plant has the lowest LCOE among all concentrating solar power (CSP) plants, and it recovers the investment after the first year of operation and the payback period is less than 2 years. It was also found that the DSG linear Fresnel solar plant with 24% of the backup system is the best and optimum solution under Algerian climates.