The thermodynamic solar power plant of the National Institute for Scientific Research in Tunisia has been in operation since 1984. The plant served as a pilot unit for exploring the technical reliability and evaluating the economic feasibility of the process of converting solar thermal energy into electricity. This paper consists of a close evaluation and analysis of the long-term performance of the system and a review of 15 years of successful operation. The aim of this study was to go over the main problems and technical difficulties encountered and pinpoint the major factors affecting the plant operation in order to identify the optimal operating policies toward the enhancement of the plant efficiency. Even though the thermal performance of the plant was relatively low, the impact of such a plant on the energy sector of the country was significant in terms of energy saving and environmental protection. In regions with high solar radiation such as Tunisia with a daily mean insolation of 4.8kWhm−2, the use of solar power plants — similar to this one — essentially for heat production prove to be a good alternative especially for remote and rural areas.