Efficiency-Optimized Hydrogen Production in PV–Battery–PEM Microgrids with Frequency Response Coordination

In industrial hydrogen production powered by high-penetration renewable energy, photovoltaic (PV) microgrids can provide low-carbon electricity for green hydrogen. However, the intermittency of PV generation and load uncertainties reduce the electrolyzer’s dwell time in its high-efficiency operating region, while imposing additional constraints on system frequency stability. This paper proposes a stochastic energy management strategy for a PV-battery-proton exchange membrane (PEM) microgrid to improve hydrogen production efficiency and ensure frequency stability. The proposed strategy uses an Efficiency-oriented Energy Allocation Markov Decision Process (EA-MDP) to model load uncertainties and incorporate available PV power into the decision-making process. The battery acts as a short-term buffer to smooth fluctuations in PV output and load demand, ensuring that the PEM electrolyzer operates efficiently despite PV intermittency. A two-timescale control strategy coordinates the Flex-MPPT with the PEM electrolyzer to maintain optimal efficiency. The strategy improves the PEM electrolyzer’s average efficiency by 14.3%, cumulative hydrogen production by 12.5% compared to traditional methods, and ensures frequency deviations are constrained within ±0.05 Hz. These results demonstrate enhanced dynamic stability, operational reliability, and efficient integration of renewable energy in the microgrid, supporting long-term sustainable hydrogen production.