Multi-Scale Thermochemical and Electrochemical Modeling for Material Scale-Up to Component and System Design


National Renewable Energy Laboratory (NREL)

Capability Expert

Zhiwen Ma, Janna Martinek


Computational Tools and Modeling

Node Readiness Category

1: High-Temperature Electrolysis (HTE)
2: Low-Temperature Electrolysis (LTE)
1: Solar Thermochemical (STCH)


This capability develops computational tools to enable the implementation of materials into a component design for assessing their performance, lifetime and reliability through high-fidelity modeling methods. NREL component and system modeling expertise can support material integration into the hydrogen generation devices and system configuration. The component modeling tools use ANSYS software as a solution framework, by adding fundamental thermochemical, electrochemical, and thermomechanical models in user defined functions, for simulations from basic material properties to a full-product design. NREL experts have experience in developing and applying the tools to predict material performance at service conditions and support the industry development. The thermochemical and electrochemical modeling tools are developed from the ground up and tailored for an individual system from basic material performance data and correlations in order to reduce prediction uncertainties. The modeling practices were previously successfully applied for fuel cell stack design and solar thermochemical hydrogen process (STCH). The capability can be used for advanced electrolysis and solar thermochemical hydrogen conversion development as a general tool for electrolyzer design or solar reactor performance optimization. The computational tools will support the electrolyzer design, performance prediction, degradation and life cycle predictions, and can accelerate the material implementation into a product with proper design and optimum performance. Thermal modeling methods developed for STCH process simulate the solar heat collection, chemical reaction, and component design.

Capability Bounds‎

The component modeling tools are for material scale-up and implementation in cell and stack level. Appropriate mathematical descriptions of the electrochemical and thermochemical processes need to be developed for any given system based on the underlying material performance from either material experimental data or theoretical modeling results. The type, size, and scale of systems that can be simulated are constrained by the complexity of the underlying physical processes with appropriate mathematical descriptions, availability of computational resources, and software licensing.

Unique Aspects‎

NREL expert developed a multi-scale electrochemical modeling tool that was used for product performance and durability improvements. The integral modeling tool accelerated implementation of new electrode or catalyst materials into electrochemical cell and stacks. NREL has developed a thermochemical model for a STCH reactor for on-sun applications. The model integrates solar heat addition, thermal performance, and chemical reaction kinetics to assess STCH material performance within a solar receiver configuration under on-sun conditions. The solar simulation programs, SolarPILOT (heliostat field) and SolTrace (Ray-tracing) developed at NREL, are able to provide concentrated solar power design through modeling of the solar field and can facilitate evaluation of the integral component models under realistic full-scale system conditions.


We have ability in developing ANSYS/Fluent-based thermochemical and electrochemical CFD models for simulating the electrolysis cell and stack. The modeling tools can predict performance and design optimization for HydroGEN material application scale-up. The existing computational capacity may be limited by the number of software licenses available for parallel computing, though this limitation can be resolved through crosscutting usage. The modeling tools can run on NREL's supercomputing facility that has powerful computing scale and is readily available and open to both internal and external users for high-performance computing.


The capability at NREL can increase availability of computational resources and expertise to the experimental community, thereby linking experimental materials research with implications on commercial system performance. The approach will accelerate material R&D and improve the computational tools to support industry for predicting product performance and life cycle. The modeling capabilities can accelerate the integration of materials into a system for commercialization.


NREL Peregrine Supercomputer.

Electrochemical-CFD model predicted fuel cell current density distribution (previous work by capability experts, not performed at NREL).

STCH – CFD model predicted H2 generation rate and prototype receiver temperature distribution (previous work by capability experts, not performed at NREL).


1. Zhiwen Ma, Ramakrishnan Venkataraman, Mohammad Farooque. (2009). "Modeling", In Juergen Garche, Chris Dyer, Patrick Moseley, Zempachi Ogumi, David Rand and Bruno Scrosati, editors. Encyclopedia of Electrochemical Power Sources, Vol 2.Amsterdam: Elsevier; 2009. pp. 519–532. 2. Zhiwen Ma, Ramakrishnan Venkataraman, and Mohammad Farooque, "Study of the Gas Flow Distribution and Heat Transfer for Externally Manifolded Fuel Cell Stack Module Using Computational Fluid Dynamics Method," J. Fuel Cell Sci. Technol., Volume 1, Issue 1, 49, November 2004. 3. Martinek, J., Viger, R., Weimer, A.W. (2014) "Transient simulation of a tubular packed bed solar receiver for hydrogen generation via metal oxide thermochemical cycles" Solar Energy 105 pp. 613-631.