In this paper, the concept of electric energy storage by a fluidized bed (EESFB) is introduced and validated. In this novel EESFB system, sand is used as the medium for energy storage. In the heating mode, sand is heated up in a fluidized bed by a group of embedded electric heating elements to a high temperature and then stored in thermally insulated tank. In the heat release mode, the stored thermal energy can be released to generate hot air, steam and electricity as necessary. Compared with other thermal energy storage technologies, EESFB is prevailing in cost-effective, environmental-friendly, high efficiency, high energy density, high flexibility to meet load fluctuations and always-ready characteristics to supply high-temperature thermal energy. It also could have a potential for massive energy storage. An experimental system with 100 kW input power was setup to study the feasibility of the novel technology. Results showed that EESFB system can be operated smoothly and sand can be efficiently heated up to a high temperature with embedded heating elements in the fluidized bed.
Keywords energy storage, electric energy storage, heat storage, fluidized bed, high temperature