A CSP system that operates at 600°C to more than 1000°C is possible because of stable materials and
minimized thermal losses due to thermal self-insulation of particles in the storage mode. The TES can hold largecapacity
thermal energy for a longer time period without the need for expensive metal alloys and insulation. The
particle-TES cost in the range of $5–$7/kW hth is possible, and may achieve >75% cost reduction over the current
TES—less than a quarter of the current TES cost estimated at $30/kWhth, or less than half of the SunShot CSP TES
cost target of $15/kW hth—to meet the SunShot cost target on TES development. The FB-TES has the potential to
support all types of power cycles, even for very high-temperature (>1000°C) needs. The uncertainty of insulation
design and the associated cost may be resolved in future CSP system integration.