Optimum design and operation of an internally-heated packed-bed tank for high-temperature solid–air energy storage: Practical application from theoretically-derived relations

A theoretically-derived design methodology for a solid–air, internally-heated thermal energy storage with localized heat application (IH-TESLA) has been presented in this study. Previous analytical solutions found by Martín-Alcántara and Fernandez-Feria (2025) have been exploited to build a set of algebraic relations useful for the practical implementation of the TES tank concept. Given the required operating conditions in terms of thermal power ( Q ≤ 100 kW) and temperature jump ( Δ T ≃ 1000 K), the derived expressions allow for the estimation of key magnitudes for the tank design such as the transient heating time, particle size, mass-flow rate, mechanical power losses, tank dimensions, and heat source thickness. Minimum values of these quantities have also been provided in the current framework. The study assesses the tank design of randomly-packed spherical particles and 4-hole cylindrical fillers, when alumina, silicon carbide (SiC), and concrete materials are used. In general, SiC particles confer a rapid thermal response, which makes the tank more appropriate for large thermal powers. However, concrete holds low thermal conductivity, and this type of fillers are intended for low power tanks. Alumina reaches a compromise between both options. The results evidence that, the current methodology can lead to an optimized design configuration for an IH-TESLA tank, given the operational needs of a heat-temperature industrial activity aiming at decarbonization. • An algebraic method is developed for the design of an IH-TES tank. • Impact of filler material, shape and size on heating transient time is analyzed. • Guidelines are provided to select filler properties for given power requirements. • Low-porosity fillers yield rapid heating while high-porosity offer design variety.