Skip navigation to main content.
NREL - National Renewable Energy Laboratory
About NRELEnergy AnalysisScience and TechnologyTechnology TransferApplying TechnologiesEnergy Systems Integration

Hydrogen Production and Delivery

Most of the hydrogen in the United States is produced by steam reforming of natural gas. For the near term, this production method will continue to dominate. Researchers at NREL are developing advanced processes to produce hydrogen economically from sustainable resources. These R&D efforts include:

Fermentation

NREL scientists are developing expertise with pretreatment technologies to convert lignocellulosic biomass into sugar-rich feedstocks including hemicelluloses and cellulose that can be fermented directly to produce hydrogen, ethanol, and high-value chemicals.

Researchers are working to identify a consortium of Clostridium that can ferment hemicellulose directly to hydrogen. Moreover, researchers are bioprospecting efficient cellulolytic microbes, such as Clostridium thermocellum, that can ferment crystalline cellulose directly to hydrogen to lower the feedstock cost. Once a model cellulolytic bacterium is identified, its potential for genetic manipulations, including sensitivity to antibiotics and ease of genetic transformation, will be determined. NREL's future fermentation projects will focus on developing strategies to generate mutants that are blocked selectively from producing waste acids and solvents through fermentation to maximize hydrogen yield.

Learn about NREL's capabilities in producing hydrogen by fermentation.

Related presentations and publications:

Contact: Pin-Ching Maness

Back to Top

Biological Water Splitting

Certain photosynthetic microbes produce hydrogen from water in their metabolic activities using light energy. Photobiological technology holds great promise, but because oxygen is produced along with the hydrogen, the technology must overcome the limitation of oxygen sensitivity of the hydrogen-evolving enzyme systems. Researchers are addressing this issue by screening for naturally occurring organisms that are more tolerant of oxygen, and by creating new genetic forms of the organisms that can sustain hydrogen production in the presence of oxygen. A new system is also being developed that uses a metabolic switch (sulfur deprivation) to cycle algal cells between a photosynthetic growth phase and a hydrogen production phase.

Related presentations and publications:

Contacts: Maria Ghirardi 303-384-6312

Back to Top

Photoelectrochemical Water Splitting

The cleanest way to produce hydrogen is by using sunlight to directly split water into hydrogen and oxygen. Multijunction cell technology developed by the photovoltaic industry is being used for photoelectrochemical (PEC) light harvesting systems that generate sufficient voltage to split water and are stable in a water/electrolyte environment. The NREL PEC system produces hydrogen from sunlight without the expense and complication of electrolyzers, at a solar-to-hydrogen conversion efficiency of 12.4% lower heating value using captured light. Research is underway to identify more efficient, lower cost materials and systems that are durable and stable against corrosion in an aqueous environment.

Related presentations and publications:

Contact: John Turner 303-275-4270, Todd Deutsch 303-275-3727

Back to Top

Conversion of Biomass and Wastes

Hydrogen can be produced via pyrolysis or gasification of biomass resources such as agricultural residues like peanut shells; consumer wastes including plastics and waste grease; or biomass specifically grown for energy uses. Biomass pyrolysis produces a liquid product (bio-oil) that contains a wide spectrum of components that can be separated into valuable chemicals and fuels, including hydrogen. NREL researchers are currently focusing on hydrogen production by catalytic reforming of biomass pyrolysis products. Specific research areas include reforming of pyrolysis streams and development and testing of fluidizable catalysts.

Related presentations and publications:

Contacts: Stefan Czernik 303-384-7703, Richard Bain 303-384-7765

Back to Top

Solar Thermal Water Splitting

NREL researchers have demonstrated that highly concentrated sunlight can be used to generate the high temperatures needed to split methane into hydrogen and carbon. Concentrated solar energy can also be used to generate temperatures of several hundred to over 2,000 degrees at which thermochemical reaction cycles can be used to produce hydrogen. Such high-temperature, high-flux solar driven thermochemical processes offer a novel approach for the environmentally benign production of hydrogen. Very high reaction rates at these elevated temperatures give rise to very fast reaction rates that enhance the production rates significantly and more than compensate for the intermittent nature of the solar resource.

Related presentations and publications:

Contact: Carl Bingham 303-384-7477

Back to Top

Renewable Electrolysis

Renewable energy sources such as photovoltaics, wind, biomass, hydro, and geothermal can provide clean and sustainable electricity for our nation. However, renewable energy sources are naturally variable, requiring energy storage or a hybrid system to accommodate daily and seasonal changes. One solution is to produce hydrogen through the electrolysis—splitting with an electric current—of water and to use that hydrogen in a fuel cell to produce electricity during times of low power production or peak demand, or to use the hydrogen in fuel cell vehicles.

NREL's Distributed Energy Resource Test Facility is an ideal location for examining the issues related to renewable energy sources and hydrogen production via the electrolysis of water. The facility offers the flexibility of interconnecting various renewable sources to electrolyzers and their hydrogen-producing stacks. NREL is testing integrated electrolysis systems and investigating options for improved designs that will lower capital costs and enhance performance of the naturally varying power input from renewable sources to the electrolyzer.

Learn more about NREL's hydrogen production cost analysis, renewable electrolysis research, and the wind-to-hydrogen project, which uses electricity from wind turbines and solar panels to produce hydrogen.

Contact: Kevin Harrison 303-384-7091 or Chris Ainscough 303-275-3781

Back to Top