This article reviews the thermal energy storage (TES) for CSPs and focuses on detailing the latest advancement in materials for TES systems and advanced thermal fluids for high energy conversion efficiency. . Thermal energy storage provides a workable solution to this challenge. In a concentrating solar power (CSP) system, the sun's rays are reflected onto a receiver, which creates heat that is used to generate electricity that can be used immediately or stored for later use. TES is ideal for energy generated through pumped heat, compressed air, concentrated solar power or molten salt. Southwest Research Institute (SwRI) is developing. . NLR researchers integrate concentrating solar power (CSP) systems with thermal energy storage to increase system efficiency, dispatchability, and flexibility. NLR researchers are leveraging expertise in thermal storage, molten salts, and power cycles to develop novel thermal storage systems that. . To eliminate its intermittence feature, thermal energy storage is vital for efficient and stable operation of solar energy utilization systems. It is an effective way of decoupling the energy demand and generation, while plays an important role on smoothing their fluctuations. In this chapter. . Thermal Energy Storage (TES) generates more efficient, reliable, and usable solar energy possible by decoupling energy generation from demand, especially in Concentrated Solar Power (CSP) plants. TES systems indirectly store thermal energy by a diverse (heat or cold) medium from which heat can. . Solar energy is the most viable and abundant renewable energy source. Its intermittent nature and mismatch between source availability and energy demand, however, are critical issues in its deployment and market penetrability. This problem can be addressed by storing surplus energy during peak sun. .