Hydrogen–Electricity Cooperative Mode Switching Mechanism and Optimization Based on Economic Trade-Off Index and Adaptive Threshold

Aiming at the economic optimization problem in the coupling application of intermittent renewable energy and electrolytic hydrogen production equipment, this paper proposes a dual-mode dynamic switching mechanism. This mechanism breaks through the limitations of the fixed operation mode and realizes intelligent switching between the two modes of hydrogen energy driven power dispatching (HDPD) and power-driven hydrogen production (PDHP) through a decision index and adaptive threshold that integrates multiple factors. The simulation results show that the proposed method achieves a total cost which is 10.6% and 16.3% lower than that of PDHP and HDPD modes, respectively. The levelized cost of hydrogen is optimized to 0.25 USD/kg, which is 34.2% lower than that of HDPD mode. Moreover, the proposed method increases hydrogen production by 14.4% compared to PDHP mode. The system maintains a high renewable energy utilization rate of 96.34% and achieves carbon emission reduction of 3.25 million kg CO2. The counterfactual test verifies the effectiveness of the switching mechanism and quantifies the opportunity cost related to decision-making. This study provides key decision-making tools and methodological references for the deployment of efficient, flexible, and economically sustainable green hydrogen energy systems.