Dynamics and control of a thermally self-sustaining energy storage system using integrated solid oxide cells for an islanded building.

A solid oxide cell-based energy system is proposed for a solar-powered stand-alone building. The system is comprised of a 5 kW el solid oxide fuel cell (SOFC), a 9.5 kW el solid oxide electrolysis cell (SOEC), and the required balance of plant. The SOFC supplies: 1- building demand in the absence of sufficient solar power, 2- heat for SOEC in endothermic and standby modes. Thermal integration of SOFC and SOEC is implemented through a network of heat exchangers, combined with set of control algorithms. Two control strategies were implemented to actuate the SOFC in response to endothermic heat demands of SOEC by manipulating: 1- electric power, 2- fuel utilization. The results of dynamic simulation of system for two scenarios (sunny day and cloudy day) showed successful compliance of temperature constraints with both methods. Manipulation of fuel utilization, however, resulted in better system performance in terms of efficiency and H 2 balance. Schematic of proposed thermally self-sustaining energy storage system. [Display omitted] • A dynamic multi-function energy system is designed for a solar PV powered building. • Power-to-Gas technology is used to convert excess electricity to hydrogen via SOEC. • SOFC is thermally integrated to SOEC to eliminate external heat sources for SOEC. • Analyzed system dynamics for two solar power scenarios: sunny day and cloudy day. • Designed two control strategies for actuating SOFC (electric power, fuel utilization). [ABSTRACT FROM AUTHOR]