Solar Electricity Generation System With Combined Energy Storage and Steam Generation

Solar steam power plants for electricity generation were launched commercially in 1984. These plants are known as SEGs projects. The oil as the heat transfer fluid (HTF) was pumped through solar field to capture solar energy. However, the oil was unable to maintain the temperature during off-sun periods. Thermal energy storage (TES) is useful to increase the solar multiple. Molten salt is usually employed as a stable energy storage medium. Two-tank and single-tank construction have been employed for parabolic trough-based solar steam power plants. In our paper, we propose an improved thermal storage concept aiming at increasing the operation hours and reducing construction cost. Our design is shown in the figure below(Figure 1,right), which incorporates the steam evaporator inside the single thermal storage tank. Aspen HYSYS is used to dynamically simulate the process, analyze the steam generation efficiency and compare with the single-tank base case(Figure 1, left).

Figure 1 Thermal storage base case and the improved design process