Integrated framework for optimal selection and capacity configuration of electric-thermal-hydrogen hybrid energy storage in distributed energy systems

To address the disconnection between scheme selection and capacity sizing of hybrid energy storage (HES) in distributed energy systems (DES), this study proposes an integrated optimization-evaluation framework for electric-thermal-hydrogen hybrid energy storage. Eight candidate schemes are constructed by combining electrical, thermal, and hydrogen storage technologies. An improved NSGA-III is adopted to obtain the optimal compromise solution for each scheme under multiple objectives. Through a five-dimensional comprehensive evaluation system combining AHP, entropy weight method (EWM), game theory, and fuzzy TOPSIS, the optimal HES scheme and its synergistic capacity configuration are determined. The results show that Scheme #7, integrating battery, hydrogen, and thermal storage, achieves the best overall performance among the eight candidate schemes. Compared with the non-storage benchmark Scheme #8, it improves exergy efficiency by 27.36%, reduces EENS by 9.71%, increases NPV by 21.11%, and enhances PESR by 19.82%. Additional comparisons with benchmark decision frameworks further verify the advantage of the proposed method in achieving a more balanced solution. Monte Carlo simulation and sensitivity analysis confirm the robustness of the selected scheme. The proposed framework provides an effective reference for decision-making in coordinated HES selection and capacity planning in DES.