A novel solids-based electro-thermal energy storage system utilizing electromagnetic induction: Conceptual design and theoretical analysis

Abstract

Electro-thermal energy storage (ETES) technology has presented its great potential to efficiently consume renewable energy and increase the flexibility of power grid. This paper presents an innovative ETES system that integrates electromagnetic induction heat storage (EIHS) with moving bed heat release (MBHR). A numerical simulation method based on CFD-DEM was developed to access the system’s performance and evaluate its technical feasibility. In a studied case, the EI heater unit achieves uniform radial temperature distribution, adjustable temperature rise rate, and high particle heat storage density, while the tubular MBHE unit shows high heat transfer intensity (678.2–784.6  W/m²/K). The system’s power-to-power conversion efficiency is approximately 30.78 %, excluding minor power consumption. The developed system offers three operation modes and two business models for peak electricity supply. The preliminary economic evaluation indicates that model 1, using valley power, has a 5-year payback period and a 21.56 % internal rate of return ($\mathrm{IRR}$), while model 2, using abandoned photovoltaic/wind power, shows a 10-year payback period and an 11.26 % $\mathrm{IRR}$. Further sensitivity analysis suggests model 1 is more cost-effective while model 2 offers slightly better risk resistance. This work has offered some valuable insights into the advanced enhancement and development of the ETES system, as well as its future engineering applications.