To serve for readily-realizable power system integration, our present analysis is still based on a conventional100-MWesteamplantwith 42.5% cycle efficiency. Based on this power system assumption, wecalculated 6-, 8-, 12-,and 16-hour TES storage capacities. An estimate of material and labor indicates that the FB-TES cost could be $5–7/kWhth,less than half of the DOE SunShot TES cost target of $15/kWhth.The cost number was derived from ourdesign work involving silo concrete structure, a foundation design based on the geological condition at Barstow,California, the storage sand cost, and a preliminary insulation design. Thecost estimate will be improved afterinsulation design andfurther confirmation with the material supplier and silo builder in future development.