Optimal operation of flexible IES based on energy hub and demand-side response

In this paper, we explored optimal operation strategies for integrated energy systems (IES) in electrolytic aluminum industrial parks, highlighting energy hubs (EH) as key to improving energy efficiency and operational flexibility. A review of IES research covers system modeling, optimization algorithms, and demand-side response (DR) strategies. By integrating EH into an energy coupling model with a DR framework, we analyzed the system's economic viability, constraints, and optimization approaches. A case study was performed to validate the model's effectiveness across scenarios. Our results demonstrated that the proposed framework significantly improves IES performance: When compared with single-energy-conversion equipment configurations, the EH-integrated model reduces total operating costs by 21.05%–38.02%. By incorporating a DR model tailored to electrolytic aluminum's rigid load characteristics, including load shifting and multi–energy substitution, the system achieves a 53.6%–62.1% reduction in wind/solar curtailment rates and shortens energy storage payback periods by 18.7%. Further analysis indicated that the DR-IES model can dynamically balance electrical and thermal loads, incentivize user participation, and enhance environmental benefits. Empirical results showed that this approach reduces total operating costs by 5.56% and narrows the peak-valley differences of electrical and thermal loads by 24.78% and 17.11%, respectively. This study provides a new paradigm for high-energy-consuming industries to achieve low–carbon transformation through the collaborative optimization of EH and DR, offering theoretical and practical guidance for energy management in industrial parks.