Session: 09-10-01: Hydrogen Production, Storage, and Integrated Hydrogen Energy Systems I

Paper Number: 167654

Dynamic Performance Analysis of High Temperature Steam Electrolysis System in an Integrated Energy Ecosystem 

Flexible loads are becoming increasingly crucial for the effective control and management of modern power grids. As the energy landscape continues to change from centralized to decentralized generation, the need for more dynamic and responsive load management has grown significantly. Rather than adjusting generator set-points, flexible electrical loads can adjust their consumption patterns in real-time, either ramping up or down in response to the prevailing grid conditions or set commands from the power utility. This adaptability provides a more economical and efficient means of ensuring grid stability, particularly in maintaining voltage and frequency balance. 

One such flexible load is High Temperature Steam Electrolysis (HTSE) which can be used for H2 production in response to leverage cheap grid electricity and providing demand response. At Idaho National Laboratory (INL), a range of HTSE test facilities has been developed to assess the dynamic operation of solid oxide electrolysis technology across the full Technology Readiness Level (TRL) spectrum. These facilities range from individual button cells to pre-commercial, sub-megawatt systems. This work presents an Integrated Energy System (IES) framework designed to coordinate the use of HTSE alongside other IES resources to provide profitable ancillary services to the grid in the form of demand response. 

As part of the effort to optimally coordinate the HTSE’s operation with existing IES power generation and load components, a coordinated control framework is proposed. It includes a ramp-constraint volt-Watt (VW) droop algorithm for the HTSE, which is formulated based on the operational dynamics of an actual grid-tied HTSE at INL. Based on the prevailing grid dynamics, the proposed coordinated optimization and control framework determines the optimal power dispatch and demand setpoints for both the HTSE and other IES resources which are set as control variables. This problem is formulated as a mixed-integer linear programming (MILP) problem and implemented in MATLAB with Modbus TCP/IP connection to a real-time digital simulation (RTDS) environment. The optimization formulation serves as a tertiary controller for the HTSE-IES setup. 

To evaluate the proposed ramp-constraint demand response schedule, an actual HTSE-integrated IES is modeled on a RTDS platform. Steady-state real-time grid measurements are taken to verify the effectiveness of the proposed coordinated control algorithm. The results demonstrate that within the operational constraints of the HTSE, significant improvements can be made to the steady-state dynamics in response to changes in variable energy resources within the grid. Although the HTSE system has some ramp constraints, these are primarily attributable to the thermal inertia of its balance of plant, rather than the limitations of the power electronic converters or the solid oxide electrolysis stacks. 

Presenting Author: Jan Lambrechtsen Idaho National Laboratory

Presenting Author Biography: Jan Lambrechtsen is a mechanical design engineer for Idaho National Laboratory in their Hydrogen & Thermal Systems group. He has two years of experience designing test facilities for high temperature steam electrolysis systems. Before working at INL, he got his bachelor's degree at Brigham Young University - Idaho and went on to earn a Masters of Science at the University of Idaho designing, building, and simulating a molten salt convection loop.

Authors:

Temitayo Olowu Idaho National Laboratory
Jan Lambrechtsen Idaho National Laboratory
Jeremy Hartvigsen Idaho National Laboratory
Micah Casteel Idaho National Laboratory