Investigation of the dynamic behavior of Brayton Batteries for Coupled Generation of Electricity, Heat, and Cooling

Abstract

This study presents a comprehensive dynamic system analysis of air-based Brayton batteries for the coupled generation of electricity, heat, and cooling. Building upon a pre-viously published structural concept study, the most promising system architectures were modeled and evaluated using quasi-stationary simulations with dynamically designed thermal energy storage (TES) in Ebsilon Professional®. The results show round-trip effi-ciencies (RTEs) of up to 50% for pure electricity generation and round-trip utilizations (RTUs) exceeding 85% for combined heat and power. Integration of waste heat further in-creases RTU to more than 100%, albeit at the expense of electrical efficiency. Dynamic sim-ulations demonstrate stable operation with load gradients up to 2 MW min-1, highlighting suitability for flexible industrial and grid applications. Regenerator-based TES exhibits the most favorable trade-off between efficiency and cost, while hybrid configurations of solid and liquid media offer additional optimization potential. The estimated investment costs range between 200 and 800 EUR/kWhel, comparable to other large-scale Carnot battery systems. The findings provide a validated framework for the techno-economic design and control of next-generation Brayton battery systems and lay the foundation for experimental validation and pilot-scale implementation.