Thermal energy storage for direct steam generation concentrating solar power plants: Concept and materials selection

Direct steam generation (DSG) concentrating solar power (CSP) plants uses water as heat transfer fluid, and it is a technology available today. It has many advantages, but its deployment is limited due to the lack of an adequate long-term thermal energy storage (TES) system. This paper presents a new TES concept for DSG CSP plants. This system is based on three blocks, a saturated block based on phase change materials, an overheating block that elevates the vapor temperature of a heat transfer fluid to the desired values, and a preheating block that increases the temperature difference between a cold tank and a hot tank of a non-phase change thermal storage material. After a deep selection and characterization process, the material to be used is LiOH/KOH, since although it has the disadvantage of high corrosion, the identified advantages overcome it as an ideal PCM for this process.