The purpose of this study is to determine an optimum design for a projected parabolic trough solar power plant (PTSPP) under Algerian climate through different funding scenarios. In this paper, seven different (d1-d7) designs for PTSPP have been developed for the Naama site. Plant size, technology type, storage capacity, location of the plant, Operation & Maintenance (O&M) costs, replacement costs, fuel consumption, net CO2 emission, levelized electricity cost, net power generation, specific investment costs and discount rate are the basis factors to determine the optimum sustainable design for PTSPP. The most attractive designs of each base technology were selected as D1, D2 and D3. The preferable design of three funding scenarios was finally selected on economic, financial and sensitivity analysis. It is finally concluded that, under the most favorable economic conditions allowed in this study, design D3 is the most advantageous in terms of benefit to cost ratio: its power output will be 100 MWel with 8 full load hours thermal energy storage. It was also found that for design D3 under funding scenario S2, the project will require an upfront grant of 396 MEUR. This corresponds to around 56% of the total investment cost and the payback period will be approximately 7 years. (C) 2014 Elsevier Ltd. All rights reserved.