NREL's renewable electrolysis research focuses on designing, developing, and testing advanced experimental and analytical methods to improve electrolyzer stack and system efficiency.
Related activities include:
- Characterizing electrolyzer performance under variable-input power conditions
- Designing and developing shared power-electronics packages and controllers to reduce system cost and optimize performance
- Identifying opportunities for cost reductions through component integration breakthroughs
- Testing, evaluating, and optimizing renewable electrolysis system performance for hydrogen production and electricity/hydrogen cogeneration.
Learn about the wind-to-hydrogen project, which uses electricity from wind turbines and solar panels to produce hydrogen.
Systems Engineering, Modeling, and Analysis
NREL develops and validates component and system models to assess and optimize a variety of system scenarios and control strategies for renewable hydrogen production and electricity/hydrogen cogeneration.
Systems Integration and Component Development
NREL develops power electronics interfaces for renewable electrolysis systems to characterize and test the performance of electrochemical devices. Testing also examines how the fluctuating power output of a wind turbine impacts electrolyzer operation. Systems performance is quantified based on the efficiency of stack and electrolyzer systems as well as their ability to accommodate renewable electricity sources.
The renewable-electrolysis systems that NREL studies incorporate a common direct current (DC) bus (electrical conductor) fixed with a battery bank connected to a wind turbine, photovoltaic array, and an electrolyzer. Typically, small wind turbines are set up to charge batteries and require connection to a constant voltage DC bus and power electronics to regulate power output and to convert wild alternating current (AC) to DC.
In commercially available electrolyzer systems, the electrolyzer stack accepts DC power input from its onboard power converter. The electrolyzer regulates power to the stack and operates at a fixed stack current. Characterization testing addresses the operation of hydrogen-producing stacks at variable current, without a fixed power supply.
Characterization and Testing
NREL works with national and international industry leaders to develop consensus-based characterization and testing protocols for renewable-based electrolyzers and to compare the performance of electrolyzers from various manufacturers.
Based on actual operational data from wind farms, photovoltaic cells, and projected load-shifting, these test protocols apply to electrolyzer operation under varying-input power conditions.
NREL uses the protocols to test on-site electrolyzers. Specific performance measures include the purity of hydrogen at low power and the long-term effects of variable power operation on electrolyzer system and stack efficiency.
NREL's renewable electrolysis research is conducted at the Energy Systems Integration Laboratory at the Energy Systems Integration Facility.