The newly adopted version of the National Renewable Energy Program of Algeria offers the country the possibility to integrate 27% of renewable energy in the national energy mix. Preservation of fossil resources, diversification of electricity production and contribution to sustainable development are among challenges that face the country nowadays. The objective of this paper is to propose a methodology and outline a procedure to determine the best configuration and the optimum design of future solar thermal power plants with minimum levelized cost of electricity (LCOE) and maximum annual power generation as objectives. Our study is based on a Concentrating Solar Power (CSP) plant of capacity of 50 MW to be erected in Hassi R'mel City, in the south of Algeria. In this methodology, the size of the solar field, the fossil fill fraction of backup system and full load hours of storage are optimized for the minimum LCOE using the concept of solar multiple. Moreover, different models, technologies and scenarios for parabolic trough and central tower receiver power plant are presented. LCOE presents a basis of comparison for weighted average costs of different power generation technologies. It is clearly shown that the solar power plant based on central receiver tower technology with 48% of backup system and 8 h of storage is the most attractive and optimum plant. It was also found from financial analysis that the LCOE can decreases by 13% with less interest rate and tax deductions. (C) 2016 Elsevier Ltd. All rights reserved.