NREL, in partnership with Xcel Energy, launched a wind-to-hydrogen (Wind2H2) demonstration project at the National Wind Technology Center in Boulder, Colorado. The Wind2H2 project links wind turbines to electrolyzers, which pass the wind-generated electricity through water to split it into hydrogen and oxygen. The hydrogen can then be stored and used later to generate electricity from an internal combustion engine or a fuel cell.
The goal of the Wind2H2 project is to improve the system efficiency of producing hydrogen from renewable resources in quantities large enough and at costs low enough to compete with traditional energy sources such as coal, oil, and natural gas.
Learn more about the Wind2H2 project through:
The Wind2H2 project uses two wind turbine technologies: a Northern Power Systems 100-kW wind turbine and a Bergey 10-kW wind turbine. Both wind turbines are variable speed, meaning the blade's speed varies with wind speed. Such wind turbines produce alternating current (AC) that varies in magnitude and frequency (known as wild AC) as the wind speed changes.
The energy from the 10-kW wind turbine is converted from its wild AC form to direct current (DC) and then used by the electrolyzer stack to produce hydrogen from water. The energy from the 100-kW wind turbine is monitored with a power transducer, and stack current on the 33-kW alkaline stack is varied proportionally.
Two HOGEN 40RE polymer electrolyte membrane electrolyzers from Proton Energy Systems and one Teledyne HMXT-100 alkaline electrolyzer produce hydrogen and oxygen from water. NREL examines the issues related to integrating these technologies as well as the operation of electrolyzers with different gas output pressures.
After compressing the hydrogen, it is stored for later use in a hydrogen internal combustion engine where it is converted to electricity and fed into the utility grid during peak demand hours. In 2009, NREL installed a new compressor, tank, and hydrogen dispenser to enable refueling of fuel cell vehicles. From December 2008 through September 2009, NREL operated a Mercedes Benz F-Cell fuel cell vehicle. Hydrogen from wind and PV were compressed to high pressure to fill the vehicle's 1.8-kg storage tank. The vehicle travels around 110 miles between refueling.
NREL's research focuses on:
- Exploring system-level integration issues related to multiple electrolyzers that produce hydrogen gas at different pressures
- Evaluating the ability to integrate energy from variable-speed wind turbines and PV arrays directly to the hydrogen-producing stacks of commercially-available electrolyzers
- Determining the system impacts and ability of each electrolyzer technology to accommodate the varying energy input from wind turbines and photovoltaics
- Quantifying system-level efficiency improvements and cost reductions by designing, building, and integrating dedicated wind-to-electrolyzer stack power electronics to enable closer coupling of wind- and PV-generated electricity and electrolyzer stack requirements
- Gaining operational experience of a hydrogen production facility, including the compression of product gas and the use of a hydrogen internal combustion engine to generate electricity during peak demand hours
- Evaluating appropriate safety systems and system controls for the safe operation of hydrogen production technologies with varying wind energy input
- Demonstrating operation of a wind-to-hydrogen system to enable evaluation of actual system costs and to identify areas for cost and efficiency improvements
- Exploring operational challenges and opportunities related to energy storage systems and their potential for addressing electric system integration issues inherent with variable wind energy resources.
In addition to this ongoing research, NREL performed an extensive analysis of the cost of producing hydrogen via wind-based water electrolysis at potential sites across the nation. The results of this analysis, performed in 2011, are provided in the hydrogen production cost analysis interactive tool.
The Wind2H2 project allows researchers to explore how to make hydrogen without producing greenhouse gases or other harmful byproducts. Most hydrogen is "reformed" from natural gas or other fossil fuels by stripping out the hydrogen atoms, a process that creates greenhouse gas emissions and eliminates some environmental benefits. Hydrogen is also produced through electrolysis using sources of electricity, such as fossil fuels, that generate air emissions.
Other benefits include:
- Creating synergies from the co-production of electricity and hydrogen
- Addressing the variable nature of wind and PV energy by storing hydrogen for later use, creating a ready source of electricity when wind is not present or when electricity demand is high
- Producing hydrogen for use in vehicles
- Comparing multiple electrolyzer technologies to gauge their efficiencies and abilities to accommodate the variable input power of wind energy
- Achieving efficiency gains though a unique, integrated AC-to-DC and DC-to-DC connection between the wind turbines, PV arrays, and the electrolyzer stacks.
Publications and Presentations
The following publications provide more information about renewable electrolysis and the wind-to-hydrogen project.
- Renewable Electrolysis Integrated System Development and Testing. Kevin Harrison. Annual Merit Review. (2014)
- Renewable Electrolysis Integrated Systems Development and Testing. Kevin Harrison, Michael Peters, and Christopher Ainscough. Annual Progress Report. (2013)
- Wind Electrolysis: Hydrogen Cost Optimization. Genevieve Saur and Todd Ramsden. (2011)
- NREL Improves System Efficiency and Increases Energy Transfer with Wind2H2 Project, Enabling Reduced Cost Electrolysis Production. Kevin Harrison and Todd Ramsden. (2010)
- Hydrogen Production: Fundamentals and Case Study Summaries. K. Harrison, R. Remick, A. Hoskin, and G. Martin. Presented at the World Hydrogen Energy Conference. (2010)
- Hydrogen for Energy Storage Analysis Overview. D. Steward, T. Ramsden, and K. Harrison. Presented at the National Hydrogen Association Conference. (2010)
- The Wind-to-Hydrogen Project: Operational Experience, Performance Testing, and Systems Integration. K. Harrison, G. Martin, T. Ramsden, and W. Kramer. (2009)
- Renewable Hydrogen: Integration, Validation, and Demonstration. K. Harrison and G. Martin. Presented at the National Hydrogen Association Conference. (2008)
Contact: Kevin Harrison 303-384-7091