Research on Integrated Energy System Optimal Operation Considering Electrolyzer Dynamic Operation and Lifetime Degradation

While green hydrogen is vital for sustainable energy transitions, the volatility of renewable power adversely affects the dynamic operation and service life of electrolyzers in integrated energy systems (IESs). To mitigate these effects while minimizing operational costs and extending the service life of electrolyzers, this paper proposes an optimization method for the operation of IESs that considers the dynamic operating characteristics and lifetime degradation of multiple types of electrolyzers. Firstly, detailed models for alkaline (ALK) electrolyzer and proton exchange membrane (PEM) electrolyzer are developed, and their start–stop characteristics and lifetime degradation characteristics are analyzed. Secondly, an optimal operation model for IES is established, taking economy as the optimization objective and considering the dynamic operating characteristics and lifetime degradation of multiple types of electrolyzers. By piecewise linearizing the hydrogen production rate of the electrolyzer, the original model is transformed into a mixed-integer linear programming model for solution. The results indicate that the proposed method can reduce the operational costs of IES, increase the proportion of stable operation time for the electrolyzer, decrease the number of startups and shutdowns, subsequently reduce the cost associated with the lifetime degradation of the electrolyzer, and specifically extend the actual lifetime of the PEM electrolyzer by 12.17% versus its rated life. Ultimately, this approach not only improves the economic viability of the system but also ensures the long-term sustainability of green hydrogen projects by minimizing equipment replacement cycles and maximizing renewable energy accommodation.