Multi-timescale Power System Operations for Electrolytic Hydrogen Generation in Integrated Nuclear-Renewable Energy Systems

This study explores how sector coupling via In- tegrated energy systems (IES) can improve the operational flexibility of the power grid, while hydrogen is gaining traction as a versatile energy carrier. Specifically, we have evaluated the operational benefits of integrating two electrolytic processes for hydrogen generation, namely low-temperature electrolysis (LTE) and high-temperature steam electrolysis (HTSE), into a nuclear- renewable IES using a 3-cycle power system operation frame- work. Detailed steady-state models of the electrolytic hydrogen generating facilities are constructed, with the HTSE process represented using standard transient models to account for the steam-bypass scheme from the nuclear reactor. These models are then integrated into a renewable-intensive power network model (specifically, the NREL 118-bus system). To simulate the operation of the integrated system across multiple timescales, a multi-timescale scheduling and dispatch tool is employed. Results indicate that while both electrolytic processes contribute to signif- icant flexibility enhancement and renewable energy curtailment reduction, the LTE process offers more operational benefits than the HTSE process across multiple timescales.