Thermocline storage for concentrated solar power plants: Descriptive review and critical analysis

The present research work is part of a desire to provide additional and necessary knowledge for the development of thermal storage technology. In concentrating solar power plants, the main objective is the economic competitiveness of the electricity production. Achieving this goal requires maintaining the sustainability of electrical energy production during the absence of solar power using stored thermal energy. Thermocline is considered as a favorable solution for thermal power storage system that achieves cost reduction for concen-trated solar power (CSP) plants. However, Thermocline uses a large quantity of material, often molten salts, in one or two huge tanks several tens of meters high and in diameter. Hence, Understanding the behavior of a thermal storage system used in a solar concentration plants. The importance of these devices has led many research groups to study the improvement of their performances in both experimental and numerical approach. In thermocline tanks, the material storing hot and cold fluid is stratified; a hot layer in the upper part and a cold layer in the lower part as well as a thermal gradient zone between both layers. This paper presents a compre-hensive survey of thermal storage based thermocline for CSP plants, their advantages, the methods enabling its performance to be improved and the different latest concepts for the combination of thermal energy system. Moreover, suggestions for future numerical and experimental research and applications guidance were also presented, as well as the different features to be studied in our current project.